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  • A Taxonomy of Numerical Methods v1

    - by JoshReuben
    Numerical Analysis – When, What, (but not how) Once you understand the Math & know C++, Numerical Methods are basically blocks of iterative & conditional math code. I found the real trick was seeing the forest for the trees – knowing which method to use for which situation. Its pretty easy to get lost in the details – so I’ve tried to organize these methods in a way that I can quickly look this up. I’ve included links to detailed explanations and to C++ code examples. I’ve tried to classify Numerical methods in the following broad categories: Solving Systems of Linear Equations Solving Non-Linear Equations Iteratively Interpolation Curve Fitting Optimization Numerical Differentiation & Integration Solving ODEs Boundary Problems Solving EigenValue problems Enjoy – I did ! Solving Systems of Linear Equations Overview Solve sets of algebraic equations with x unknowns The set is commonly in matrix form Gauss-Jordan Elimination http://en.wikipedia.org/wiki/Gauss%E2%80%93Jordan_elimination C++: http://www.codekeep.net/snippets/623f1923-e03c-4636-8c92-c9dc7aa0d3c0.aspx Produces solution of the equations & the coefficient matrix Efficient, stable 2 steps: · Forward Elimination – matrix decomposition: reduce set to triangular form (0s below the diagonal) or row echelon form. If degenerate, then there is no solution · Backward Elimination –write the original matrix as the product of ints inverse matrix & its reduced row-echelon matrix à reduce set to row canonical form & use back-substitution to find the solution to the set Elementary ops for matrix decomposition: · Row multiplication · Row switching · Add multiples of rows to other rows Use pivoting to ensure rows are ordered for achieving triangular form LU Decomposition http://en.wikipedia.org/wiki/LU_decomposition C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-lu-decomposition-for-solving.html Represent the matrix as a product of lower & upper triangular matrices A modified version of GJ Elimination Advantage – can easily apply forward & backward elimination to solve triangular matrices Techniques: · Doolittle Method – sets the L matrix diagonal to unity · Crout Method - sets the U matrix diagonal to unity Note: both the L & U matrices share the same unity diagonal & can be stored compactly in the same matrix Gauss-Seidel Iteration http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method C++: http://www.nr.com/forum/showthread.php?t=722 Transform the linear set of equations into a single equation & then use numerical integration (as integration formulas have Sums, it is implemented iteratively). an optimization of Gauss-Jacobi: 1.5 times faster, requires 0.25 iterations to achieve the same tolerance Solving Non-Linear Equations Iteratively find roots of polynomials – there may be 0, 1 or n solutions for an n order polynomial use iterative techniques Iterative methods · used when there are no known analytical techniques · Requires set functions to be continuous & differentiable · Requires an initial seed value – choice is critical to convergence à conduct multiple runs with different starting points & then select best result · Systematic - iterate until diminishing returns, tolerance or max iteration conditions are met · bracketing techniques will always yield convergent solutions, non-bracketing methods may fail to converge Incremental method if a nonlinear function has opposite signs at 2 ends of a small interval x1 & x2, then there is likely to be a solution in their interval – solutions are detected by evaluating a function over interval steps, for a change in sign, adjusting the step size dynamically. Limitations – can miss closely spaced solutions in large intervals, cannot detect degenerate (coinciding) solutions, limited to functions that cross the x-axis, gives false positives for singularities Fixed point method http://en.wikipedia.org/wiki/Fixed-point_iteration C++: http://books.google.co.il/books?id=weYj75E_t6MC&pg=PA79&lpg=PA79&dq=fixed+point+method++c%2B%2B&source=bl&ots=LQ-5P_taoC&sig=lENUUIYBK53tZtTwNfHLy5PEWDk&hl=en&sa=X&ei=wezDUPW1J5DptQaMsIHQCw&redir_esc=y#v=onepage&q=fixed%20point%20method%20%20c%2B%2B&f=false Algebraically rearrange a solution to isolate a variable then apply incremental method Bisection method http://en.wikipedia.org/wiki/Bisection_method C++: http://numericalcomputing.wordpress.com/category/algorithms/ Bracketed - Select an initial interval, keep bisecting it ad midpoint into sub-intervals and then apply incremental method on smaller & smaller intervals – zoom in Adv: unaffected by function gradient à reliable Disadv: slow convergence False Position Method http://en.wikipedia.org/wiki/False_position_method C++: http://www.dreamincode.net/forums/topic/126100-bisection-and-false-position-methods/ Bracketed - Select an initial interval , & use the relative value of function at interval end points to select next sub-intervals (estimate how far between the end points the solution might be & subdivide based on this) Newton-Raphson method http://en.wikipedia.org/wiki/Newton's_method C++: http://www-users.cselabs.umn.edu/classes/Summer-2012/csci1113/index.php?page=./newt3 Also known as Newton's method Convenient, efficient Not bracketed – only a single initial guess is required to start iteration – requires an analytical expression for the first derivative of the function as input. Evaluates the function & its derivative at each step. Can be extended to the Newton MutiRoot method for solving multiple roots Can be easily applied to an of n-coupled set of non-linear equations – conduct a Taylor Series expansion of a function, dropping terms of order n, rewrite as a Jacobian matrix of PDs & convert to simultaneous linear equations !!! Secant Method http://en.wikipedia.org/wiki/Secant_method C++: http://forum.vcoderz.com/showthread.php?p=205230 Unlike N-R, can estimate first derivative from an initial interval (does not require root to be bracketed) instead of inputting it Since derivative is approximated, may converge slower. Is fast in practice as it does not have to evaluate the derivative at each step. Similar implementation to False Positive method Birge-Vieta Method http://mat.iitm.ac.in/home/sryedida/public_html/caimna/transcendental/polynomial%20methods/bv%20method.html C++: http://books.google.co.il/books?id=cL1boM2uyQwC&pg=SA3-PA51&lpg=SA3-PA51&dq=Birge-Vieta+Method+c%2B%2B&source=bl&ots=QZmnDTK3rC&sig=BPNcHHbpR_DKVoZXrLi4nVXD-gg&hl=en&sa=X&ei=R-_DUK2iNIjzsgbE5ID4Dg&redir_esc=y#v=onepage&q=Birge-Vieta%20Method%20c%2B%2B&f=false combines Horner's method of polynomial evaluation (transforming into lesser degree polynomials that are more computationally efficient to process) with Newton-Raphson to provide a computational speed-up Interpolation Overview Construct new data points for as close as possible fit within range of a discrete set of known points (that were obtained via sampling, experimentation) Use Taylor Series Expansion of a function f(x) around a specific value for x Linear Interpolation http://en.wikipedia.org/wiki/Linear_interpolation C++: http://www.hamaluik.com/?p=289 Straight line between 2 points à concatenate interpolants between each pair of data points Bilinear Interpolation http://en.wikipedia.org/wiki/Bilinear_interpolation C++: http://supercomputingblog.com/graphics/coding-bilinear-interpolation/2/ Extension of the linear function for interpolating functions of 2 variables – perform linear interpolation first in 1 direction, then in another. Used in image processing – e.g. texture mapping filter. Uses 4 vertices to interpolate a value within a unit cell. Lagrange Interpolation http://en.wikipedia.org/wiki/Lagrange_polynomial C++: http://www.codecogs.com/code/maths/approximation/interpolation/lagrange.php For polynomials Requires recomputation for all terms for each distinct x value – can only be applied for small number of nodes Numerically unstable Barycentric Interpolation http://epubs.siam.org/doi/pdf/10.1137/S0036144502417715 C++: http://www.gamedev.net/topic/621445-barycentric-coordinates-c-code-check/ Rearrange the terms in the equation of the Legrange interpolation by defining weight functions that are independent of the interpolated value of x Newton Divided Difference Interpolation http://en.wikipedia.org/wiki/Newton_polynomial C++: http://jee-appy.blogspot.co.il/2011/12/newton-divided-difference-interpolation.html Hermite Divided Differences: Interpolation polynomial approximation for a given set of data points in the NR form - divided differences are used to approximately calculate the various differences. For a given set of 3 data points , fit a quadratic interpolant through the data Bracketed functions allow Newton divided differences to be calculated recursively Difference table Cubic Spline Interpolation http://en.wikipedia.org/wiki/Spline_interpolation C++: https://www.marcusbannerman.co.uk/index.php/home/latestarticles/42-articles/96-cubic-spline-class.html Spline is a piecewise polynomial Provides smoothness – for interpolations with significantly varying data Use weighted coefficients to bend the function to be smooth & its 1st & 2nd derivatives are continuous through the edge points in the interval Curve Fitting A generalization of interpolating whereby given data points may contain noise à the curve does not necessarily pass through all the points Least Squares Fit http://en.wikipedia.org/wiki/Least_squares C++: http://www.ccas.ru/mmes/educat/lab04k/02/least-squares.c Residual – difference between observed value & expected value Model function is often chosen as a linear combination of the specified functions Determines: A) The model instance in which the sum of squared residuals has the least value B) param values for which model best fits data Straight Line Fit Linear correlation between independent variable and dependent variable Linear Regression http://en.wikipedia.org/wiki/Linear_regression C++: http://www.oocities.org/david_swaim/cpp/linregc.htm Special case of statistically exact extrapolation Leverage least squares Given a basis function, the sum of the residuals is determined and the corresponding gradient equation is expressed as a set of normal linear equations in matrix form that can be solved (e.g. using LU Decomposition) Can be weighted - Drop the assumption that all errors have the same significance –-> confidence of accuracy is different for each data point. Fit the function closer to points with higher weights Polynomial Fit - use a polynomial basis function Moving Average http://en.wikipedia.org/wiki/Moving_average C++: http://www.codeproject.com/Articles/17860/A-Simple-Moving-Average-Algorithm Used for smoothing (cancel fluctuations to highlight longer-term trends & cycles), time series data analysis, signal processing filters Replace each data point with average of neighbors. Can be simple (SMA), weighted (WMA), exponential (EMA). Lags behind latest data points – extra weight can be given to more recent data points. Weights can decrease arithmetically or exponentially according to distance from point. Parameters: smoothing factor, period, weight basis Optimization Overview Given function with multiple variables, find Min (or max by minimizing –f(x)) Iterative approach Efficient, but not necessarily reliable Conditions: noisy data, constraints, non-linear models Detection via sign of first derivative - Derivative of saddle points will be 0 Local minima Bisection method Similar method for finding a root for a non-linear equation Start with an interval that contains a minimum Golden Search method http://en.wikipedia.org/wiki/Golden_section_search C++: http://www.codecogs.com/code/maths/optimization/golden.php Bisect intervals according to golden ratio 0.618.. Achieves reduction by evaluating a single function instead of 2 Newton-Raphson Method Brent method http://en.wikipedia.org/wiki/Brent's_method C++: http://people.sc.fsu.edu/~jburkardt/cpp_src/brent/brent.cpp Based on quadratic or parabolic interpolation – if the function is smooth & parabolic near to the minimum, then a parabola fitted through any 3 points should approximate the minima – fails when the 3 points are collinear , in which case the denominator is 0 Simplex Method http://en.wikipedia.org/wiki/Simplex_algorithm C++: http://www.codeguru.com/cpp/article.php/c17505/Simplex-Optimization-Algorithm-and-Implemetation-in-C-Programming.htm Find the global minima of any multi-variable function Direct search – no derivatives required At each step it maintains a non-degenerative simplex – a convex hull of n+1 vertices. Obtains the minimum for a function with n variables by evaluating the function at n-1 points, iteratively replacing the point of worst result with the point of best result, shrinking the multidimensional simplex around the best point. Point replacement involves expanding & contracting the simplex near the worst value point to determine a better replacement point Oscillation can be avoided by choosing the 2nd worst result Restart if it gets stuck Parameters: contraction & expansion factors Simulated Annealing http://en.wikipedia.org/wiki/Simulated_annealing C++: http://code.google.com/p/cppsimulatedannealing/ Analogy to heating & cooling metal to strengthen its structure Stochastic method – apply random permutation search for global minima - Avoid entrapment in local minima via hill climbing Heating schedule - Annealing schedule params: temperature, iterations at each temp, temperature delta Cooling schedule – can be linear, step-wise or exponential Differential Evolution http://en.wikipedia.org/wiki/Differential_evolution C++: http://www.amichel.com/de/doc/html/ More advanced stochastic methods analogous to biological processes: Genetic algorithms, evolution strategies Parallel direct search method against multiple discrete or continuous variables Initial population of variable vectors chosen randomly – if weighted difference vector of 2 vectors yields a lower objective function value then it replaces the comparison vector Many params: #parents, #variables, step size, crossover constant etc Convergence is slow – many more function evaluations than simulated annealing Numerical Differentiation Overview 2 approaches to finite difference methods: · A) approximate function via polynomial interpolation then differentiate · B) Taylor series approximation – additionally provides error estimate Finite Difference methods http://en.wikipedia.org/wiki/Finite_difference_method C++: http://www.wpi.edu/Pubs/ETD/Available/etd-051807-164436/unrestricted/EAMPADU.pdf Find differences between high order derivative values - Approximate differential equations by finite differences at evenly spaced data points Based on forward & backward Taylor series expansion of f(x) about x plus or minus multiples of delta h. Forward / backward difference - the sums of the series contains even derivatives and the difference of the series contains odd derivatives – coupled equations that can be solved. Provide an approximation of the derivative within a O(h^2) accuracy There is also central difference & extended central difference which has a O(h^4) accuracy Richardson Extrapolation http://en.wikipedia.org/wiki/Richardson_extrapolation C++: http://mathscoding.blogspot.co.il/2012/02/introduction-richardson-extrapolation.html A sequence acceleration method applied to finite differences Fast convergence, high accuracy O(h^4) Derivatives via Interpolation Cannot apply Finite Difference method to discrete data points at uneven intervals – so need to approximate the derivative of f(x) using the derivative of the interpolant via 3 point Lagrange Interpolation Note: the higher the order of the derivative, the lower the approximation precision Numerical Integration Estimate finite & infinite integrals of functions More accurate procedure than numerical differentiation Use when it is not possible to obtain an integral of a function analytically or when the function is not given, only the data points are Newton Cotes Methods http://en.wikipedia.org/wiki/Newton%E2%80%93Cotes_formulas C++: http://www.siafoo.net/snippet/324 For equally spaced data points Computationally easy – based on local interpolation of n rectangular strip areas that is piecewise fitted to a polynomial to get the sum total area Evaluate the integrand at n+1 evenly spaced points – approximate definite integral by Sum Weights are derived from Lagrange Basis polynomials Leverage Trapezoidal Rule for default 2nd formulas, Simpson 1/3 Rule for substituting 3 point formulas, Simpson 3/8 Rule for 4 point formulas. For 4 point formulas use Bodes Rule. Higher orders obtain more accurate results Trapezoidal Rule uses simple area, Simpsons Rule replaces the integrand f(x) with a quadratic polynomial p(x) that uses the same values as f(x) for its end points, but adds a midpoint Romberg Integration http://en.wikipedia.org/wiki/Romberg's_method C++: http://code.google.com/p/romberg-integration/downloads/detail?name=romberg.cpp&can=2&q= Combines trapezoidal rule with Richardson Extrapolation Evaluates the integrand at equally spaced points The integrand must have continuous derivatives Each R(n,m) extrapolation uses a higher order integrand polynomial replacement rule (zeroth starts with trapezoidal) à a lower triangular matrix set of equation coefficients where the bottom right term has the most accurate approximation. The process continues until the difference between 2 successive diagonal terms becomes sufficiently small. Gaussian Quadrature http://en.wikipedia.org/wiki/Gaussian_quadrature C++: http://www.alglib.net/integration/gaussianquadratures.php Data points are chosen to yield best possible accuracy – requires fewer evaluations Ability to handle singularities, functions that are difficult to evaluate The integrand can include a weighting function determined by a set of orthogonal polynomials. Points & weights are selected so that the integrand yields the exact integral if f(x) is a polynomial of degree <= 2n+1 Techniques (basically different weighting functions): · Gauss-Legendre Integration w(x)=1 · Gauss-Laguerre Integration w(x)=e^-x · Gauss-Hermite Integration w(x)=e^-x^2 · Gauss-Chebyshev Integration w(x)= 1 / Sqrt(1-x^2) Solving ODEs Use when high order differential equations cannot be solved analytically Evaluated under boundary conditions RK for systems – a high order differential equation can always be transformed into a coupled first order system of equations Euler method http://en.wikipedia.org/wiki/Euler_method C++: http://rosettacode.org/wiki/Euler_method First order Runge–Kutta method. Simple recursive method – given an initial value, calculate derivative deltas. Unstable & not very accurate (O(h) error) – not used in practice A first-order method - the local error (truncation error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size In evolving solution between data points xn & xn+1, only evaluates derivatives at beginning of interval xn à asymmetric at boundaries Higher order Runge Kutta http://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods C++: http://www.dreamincode.net/code/snippet1441.htm 2nd & 4th order RK - Introduces parameterized midpoints for more symmetric solutions à accuracy at higher computational cost Adaptive RK – RK-Fehlberg – estimate the truncation at each integration step & automatically adjust the step size to keep error within prescribed limits. At each step 2 approximations are compared – if in disagreement to a specific accuracy, the step size is reduced Boundary Value Problems Where solution of differential equations are located at 2 different values of the independent variable x à more difficult, because cannot just start at point of initial value – there may not be enough starting conditions available at the end points to produce a unique solution An n-order equation will require n boundary conditions – need to determine the missing n-1 conditions which cause the given conditions at the other boundary to be satisfied Shooting Method http://en.wikipedia.org/wiki/Shooting_method C++: http://ganeshtiwaridotcomdotnp.blogspot.co.il/2009/12/c-c-code-shooting-method-for-solving.html Iteratively guess the missing values for one end & integrate, then inspect the discrepancy with the boundary values of the other end to adjust the estimate Given the starting boundary values u1 & u2 which contain the root u, solve u given the false position method (solving the differential equation as an initial value problem via 4th order RK), then use u to solve the differential equations. Finite Difference Method For linear & non-linear systems Higher order derivatives require more computational steps – some combinations for boundary conditions may not work though Improve the accuracy by increasing the number of mesh points Solving EigenValue Problems An eigenvalue can substitute a matrix when doing matrix multiplication à convert matrix multiplication into a polynomial EigenValue For a given set of equations in matrix form, determine what are the solution eigenvalue & eigenvectors Similar Matrices - have same eigenvalues. Use orthogonal similarity transforms to reduce a matrix to diagonal form from which eigenvalue(s) & eigenvectors can be computed iteratively Jacobi method http://en.wikipedia.org/wiki/Jacobi_method C++: http://people.sc.fsu.edu/~jburkardt/classes/acs2_2008/openmp/jacobi/jacobi.html Robust but Computationally intense – use for small matrices < 10x10 Power Iteration http://en.wikipedia.org/wiki/Power_iteration For any given real symmetric matrix, generate the largest single eigenvalue & its eigenvectors Simplest method – does not compute matrix decomposition à suitable for large, sparse matrices Inverse Iteration Variation of power iteration method – generates the smallest eigenvalue from the inverse matrix Rayleigh Method http://en.wikipedia.org/wiki/Rayleigh's_method_of_dimensional_analysis Variation of power iteration method Rayleigh Quotient Method Variation of inverse iteration method Matrix Tri-diagonalization Method Use householder algorithm to reduce an NxN symmetric matrix to a tridiagonal real symmetric matrix vua N-2 orthogonal transforms     Whats Next Outside of Numerical Methods there are lots of different types of algorithms that I’ve learned over the decades: Data Mining – (I covered this briefly in a previous post: http://geekswithblogs.net/JoshReuben/archive/2007/12/31/ssas-dm-algorithms.aspx ) Search & Sort Routing Problem Solving Logical Theorem Proving Planning Probabilistic Reasoning Machine Learning Solvers (eg MIP) Bioinformatics (Sequence Alignment, Protein Folding) Quant Finance (I read Wilmott’s books – interesting) Sooner or later, I’ll cover the above topics as well.

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  • C#/.NET Little Wonders: The Generic Func Delegates

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Back in one of my three original “Little Wonders” Trilogy of posts, I had listed generic delegates as one of the Little Wonders of .NET.  Later, someone posted a comment saying said that they would love more detail on the generic delegates and their uses, since my original entry just scratched the surface of them. Last week, I began our look at some of the handy generic delegates built into .NET with a description of delegates in general, and the Action family of delegates.  For this week, I’ll launch into a look at the Func family of generic delegates and how they can be used to support generic, reusable algorithms and classes. Quick Delegate Recap Delegates are similar to function pointers in C++ in that they allow you to store a reference to a method.  They can store references to either static or instance methods, and can actually be used to chain several methods together in one delegate. Delegates are very type-safe and can be satisfied with any standard method, anonymous method, or a lambda expression.  They can also be null as well (refers to no method), so care should be taken to make sure that the delegate is not null before you invoke it. Delegates are defined using the keyword delegate, where the delegate’s type name is placed where you would typically place the method name: 1: // This delegate matches any method that takes string, returns nothing 2: public delegate void Log(string message); This delegate defines a delegate type named Log that can be used to store references to any method(s) that satisfies its signature (whether instance, static, lambda expression, etc.). Delegate instances then can be assigned zero (null) or more methods using the operator = which replaces the existing delegate chain, or by using the operator += which adds a method to the end of a delegate chain: 1: // creates a delegate instance named currentLogger defaulted to Console.WriteLine (static method) 2: Log currentLogger = Console.Out.WriteLine; 3:  4: // invokes the delegate, which writes to the console out 5: currentLogger("Hi Standard Out!"); 6:  7: // append a delegate to Console.Error.WriteLine to go to std error 8: currentLogger += Console.Error.WriteLine; 9:  10: // invokes the delegate chain and writes message to std out and std err 11: currentLogger("Hi Standard Out and Error!"); While delegates give us a lot of power, it can be cumbersome to re-create fairly standard delegate definitions repeatedly, for this purpose the generic delegates were introduced in various stages in .NET.  These support various method types with particular signatures. Note: a caveat with generic delegates is that while they can support multiple parameters, they do not match methods that contains ref or out parameters. If you want to a delegate to represent methods that takes ref or out parameters, you will need to create a custom delegate. We’ve got the Func… delegates Just like it’s cousin, the Action delegate family, the Func delegate family gives us a lot of power to use generic delegates to make classes and algorithms more generic.  Using them keeps us from having to define a new delegate type when need to make a class or algorithm generic. Remember that the point of the Action delegate family was to be able to perform an “action” on an item, with no return results.  Thus Action delegates can be used to represent most methods that take 0 to 16 arguments but return void.  You can assign a method The Func delegate family was introduced in .NET 3.5 with the advent of LINQ, and gives us the power to define a function that can be called on 0 to 16 arguments and returns a result.  Thus, the main difference between Action and Func, from a delegate perspective, is that Actions return nothing, but Funcs return a result. The Func family of delegates have signatures as follows: Func<TResult> – matches a method that takes no arguments, and returns value of type TResult. Func<T, TResult> – matches a method that takes an argument of type T, and returns value of type TResult. Func<T1, T2, TResult> – matches a method that takes arguments of type T1 and T2, and returns value of type TResult. Func<T1, T2, …, TResult> – and so on up to 16 arguments, and returns value of type TResult. These are handy because they quickly allow you to be able to specify that a method or class you design will perform a function to produce a result as long as the method you specify meets the signature. For example, let’s say you were designing a generic aggregator, and you wanted to allow the user to define how the values will be aggregated into the result (i.e. Sum, Min, Max, etc…).  To do this, we would ask the user of our class to pass in a method that would take the current total, the next value, and produce a new total.  A class like this could look like: 1: public sealed class Aggregator<TValue, TResult> 2: { 3: // holds method that takes previous result, combines with next value, creates new result 4: private Func<TResult, TValue, TResult> _aggregationMethod; 5:  6: // gets or sets the current result of aggregation 7: public TResult Result { get; private set; } 8:  9: // construct the aggregator given the method to use to aggregate values 10: public Aggregator(Func<TResult, TValue, TResult> aggregationMethod = null) 11: { 12: if (aggregationMethod == null) throw new ArgumentNullException("aggregationMethod"); 13:  14: _aggregationMethod = aggregationMethod; 15: } 16:  17: // method to add next value 18: public void Aggregate(TValue nextValue) 19: { 20: // performs the aggregation method function on the current result and next and sets to current result 21: Result = _aggregationMethod(Result, nextValue); 22: } 23: } Of course, LINQ already has an Aggregate extension method, but that works on a sequence of IEnumerable<T>, whereas this is designed to work more with aggregating single results over time (such as keeping track of a max response time for a service). We could then use this generic aggregator to find the sum of a series of values over time, or the max of a series of values over time (among other things): 1: // creates an aggregator that adds the next to the total to sum the values 2: var sumAggregator = new Aggregator<int, int>((total, next) => total + next); 3:  4: // creates an aggregator (using static method) that returns the max of previous result and next 5: var maxAggregator = new Aggregator<int, int>(Math.Max); So, if we were timing the response time of a web method every time it was called, we could pass that response time to both of these aggregators to get an idea of the total time spent in that web method, and the max time spent in any one call to the web method: 1: // total will be 13 and max 13 2: int responseTime = 13; 3: sumAggregator.Aggregate(responseTime); 4: maxAggregator.Aggregate(responseTime); 5:  6: // total will be 20 and max still 13 7: responseTime = 7; 8: sumAggregator.Aggregate(responseTime); 9: maxAggregator.Aggregate(responseTime); 10:  11: // total will be 40 and max now 20 12: responseTime = 20; 13: sumAggregator.Aggregate(responseTime); 14: maxAggregator.Aggregate(responseTime); The Func delegate family is useful for making generic algorithms and classes, and in particular allows the caller of the method or user of the class to specify a function to be performed in order to generate a result. What is the result of a Func delegate chain? If you remember, we said earlier that you can assign multiple methods to a delegate by using the += operator to chain them.  So how does this affect delegates such as Func that return a value, when applied to something like the code below? 1: Func<int, int, int> combo = null; 2:  3: // What if we wanted to aggregate the sum and max together? 4: combo += (total, next) => total + next; 5: combo += Math.Max; 6:  7: // what is the result? 8: var comboAggregator = new Aggregator<int, int>(combo); Well, in .NET if you chain multiple methods in a delegate, they will all get invoked, but the result of the delegate is the result of the last method invoked in the chain.  Thus, this aggregator would always result in the Math.Max() result.  The other chained method (the sum) gets executed first, but it’s result is thrown away: 1: // result is 13 2: int responseTime = 13; 3: comboAggregator.Aggregate(responseTime); 4:  5: // result is still 13 6: responseTime = 7; 7: comboAggregator.Aggregate(responseTime); 8:  9: // result is now 20 10: responseTime = 20; 11: comboAggregator.Aggregate(responseTime); So remember, you can chain multiple Func (or other delegates that return values) together, but if you do so you will only get the last executed result. Func delegates and co-variance/contra-variance in .NET 4.0 Just like the Action delegate, as of .NET 4.0, the Func delegate family is contra-variant on its arguments.  In addition, it is co-variant on its return type.  To support this, in .NET 4.0 the signatures of the Func delegates changed to: Func<out TResult> – matches a method that takes no arguments, and returns value of type TResult (or a more derived type). Func<in T, out TResult> – matches a method that takes an argument of type T (or a less derived type), and returns value of type TResult(or a more derived type). Func<in T1, in T2, out TResult> – matches a method that takes arguments of type T1 and T2 (or less derived types), and returns value of type TResult (or a more derived type). Func<in T1, in T2, …, out TResult> – and so on up to 16 arguments, and returns value of type TResult (or a more derived type). Notice the addition of the in and out keywords before each of the generic type placeholders.  As we saw last week, the in keyword is used to specify that a generic type can be contra-variant -- it can match the given type or a type that is less derived.  However, the out keyword, is used to specify that a generic type can be co-variant -- it can match the given type or a type that is more derived. On contra-variance, if you are saying you need an function that will accept a string, you can just as easily give it an function that accepts an object.  In other words, if you say “give me an function that will process dogs”, I could pass you a method that will process any animal, because all dogs are animals.  On the co-variance side, if you are saying you need a function that returns an object, you can just as easily pass it a function that returns a string because any string returned from the given method can be accepted by a delegate expecting an object result, since string is more derived.  Once again, in other words, if you say “give me a method that creates an animal”, I can pass you a method that will create a dog, because all dogs are animals. It really all makes sense, you can pass a more specific thing to a less specific parameter, and you can return a more specific thing as a less specific result.  In other words, pay attention to the direction the item travels (parameters go in, results come out).  Keeping that in mind, you can always pass more specific things in and return more specific things out. For example, in the code below, we have a method that takes a Func<object> to generate an object, but we can pass it a Func<string> because the return type of object can obviously accept a return value of string as well: 1: // since Func<object> is co-variant, this will access Func<string>, etc... 2: public static string Sequence(int count, Func<object> generator) 3: { 4: var builder = new StringBuilder(); 5:  6: for (int i=0; i<count; i++) 7: { 8: object value = generator(); 9: builder.Append(value); 10: } 11:  12: return builder.ToString(); 13: } Even though the method above takes a Func<object>, we can pass a Func<string> because the TResult type placeholder is co-variant and accepts types that are more derived as well: 1: // delegate that's typed to return string. 2: Func<string> stringGenerator = () => DateTime.Now.ToString(); 3:  4: // This will work in .NET 4.0, but not in previous versions 5: Sequence(100, stringGenerator); Previous versions of .NET implemented some forms of co-variance and contra-variance before, but .NET 4.0 goes one step further and allows you to pass or assign an Func<A, BResult> to a Func<Y, ZResult> as long as A is less derived (or same) as Y, and BResult is more derived (or same) as ZResult. Sidebar: The Func and the Predicate A method that takes one argument and returns a bool is generally thought of as a predicate.  Predicates are used to examine an item and determine whether that item satisfies a particular condition.  Predicates are typically unary, but you may also have binary and other predicates as well. Predicates are often used to filter results, such as in the LINQ Where() extension method: 1: var numbers = new[] { 1, 2, 4, 13, 8, 10, 27 }; 2:  3: // call Where() using a predicate which determines if the number is even 4: var evens = numbers.Where(num => num % 2 == 0); As of .NET 3.5, predicates are typically represented as Func<T, bool> where T is the type of the item to examine.  Previous to .NET 3.5, there was a Predicate<T> type that tended to be used (which we’ll discuss next week) and is still supported, but most developers recommend using Func<T, bool> now, as it prevents confusion with overloads that accept unary predicates and binary predicates, etc.: 1: // this seems more confusing as an overload set, because of Predicate vs Func 2: public static SomeMethod(Predicate<int> unaryPredicate) { } 3: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } 4:  5: // this seems more consistent as an overload set, since just uses Func 6: public static SomeMethod(Func<int, bool> unaryPredicate) { } 7: public static SomeMethod(Func<int, int, bool> binaryPredicate) { } Also, even though Predicate<T> and Func<T, bool> match the same signatures, they are separate types!  Thus you cannot assign a Predicate<T> instance to a Func<T, bool> instance and vice versa: 1: // the same method, lambda expression, etc can be assigned to both 2: Predicate<int> isEven = i => (i % 2) == 0; 3: Func<int, bool> alsoIsEven = i => (i % 2) == 0; 4:  5: // but the delegate instances cannot be directly assigned, strongly typed! 6: // ERROR: cannot convert type... 7: isEven = alsoIsEven; 8:  9: // however, you can assign by wrapping in a new instance: 10: isEven = new Predicate<int>(alsoIsEven); 11: alsoIsEven = new Func<int, bool>(isEven); So, the general advice that seems to come from most developers is that Predicate<T> is still supported, but we should use Func<T, bool> for consistency in .NET 3.5 and above. Sidebar: Func as a Generator for Unit Testing One area of difficulty in unit testing can be unit testing code that is based on time of day.  We’d still want to unit test our code to make sure the logic is accurate, but we don’t want the results of our unit tests to be dependent on the time they are run. One way (of many) around this is to create an internal generator that will produce the “current” time of day.  This would default to returning result from DateTime.Now (or some other method), but we could inject specific times for our unit testing.  Generators are typically methods that return (generate) a value for use in a class/method. For example, say we are creating a CacheItem<T> class that represents an item in the cache, and we want to make sure the item shows as expired if the age is more than 30 seconds.  Such a class could look like: 1: // responsible for maintaining an item of type T in the cache 2: public sealed class CacheItem<T> 3: { 4: // helper method that returns the current time 5: private static Func<DateTime> _timeGenerator = () => DateTime.Now; 6:  7: // allows internal access to the time generator 8: internal static Func<DateTime> TimeGenerator 9: { 10: get { return _timeGenerator; } 11: set { _timeGenerator = value; } 12: } 13:  14: // time the item was cached 15: public DateTime CachedTime { get; private set; } 16:  17: // the item cached 18: public T Value { get; private set; } 19:  20: // item is expired if older than 30 seconds 21: public bool IsExpired 22: { 23: get { return _timeGenerator() - CachedTime > TimeSpan.FromSeconds(30.0); } 24: } 25:  26: // creates the new cached item, setting cached time to "current" time 27: public CacheItem(T value) 28: { 29: Value = value; 30: CachedTime = _timeGenerator(); 31: } 32: } Then, we can use this construct to unit test our CacheItem<T> without any time dependencies: 1: var baseTime = DateTime.Now; 2:  3: // start with current time stored above (so doesn't drift) 4: CacheItem<int>.TimeGenerator = () => baseTime; 5:  6: var target = new CacheItem<int>(13); 7:  8: // now add 15 seconds, should still be non-expired 9: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(15); 10:  11: Assert.IsFalse(target.IsExpired); 12:  13: // now add 31 seconds, should now be expired 14: CacheItem<int>.TimeGenerator = () => baseTime.AddSeconds(31); 15:  16: Assert.IsTrue(target.IsExpired); Now we can unit test for 1 second before, 1 second after, 1 millisecond before, 1 day after, etc.  Func delegates can be a handy tool for this type of value generation to support more testable code.  Summary Generic delegates give us a lot of power to make truly generic algorithms and classes.  The Func family of delegates is a great way to be able to specify functions to calculate a result based on 0-16 arguments.  Stay tuned in the weeks that follow for other generic delegates in the .NET Framework!   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Func, Delegates

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  • Realtek RTL8111/8168B wired network doesn't work anymore

    - by Radar4002
    This sounds like it's a common problem upgrading 11.04, but I am having trouble finding a common solution, and one that will work for me. I just applied updates via the update manager and now my wired network connection is down. I know Ubuntu network settings is the issue, because I have a dual-boot with Win 7 and my network/internet is fine on Win 7. I don't know too much about networking, so what can I do to trouble shoot this issue? I can choose an older grub version, 2.6.38-8 instead of 2.6.38-11 and this does not resolve the issue. Here is my lspci result: 00:00.0 Host bridge: ATI Technologies Inc RD890 Northbridge only single slot PCI-e GFX Hydra part (rev 02) 00:02.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port B) 00:04.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port D) 00:05.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port E) 00:06.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port F) 00:07.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port G) 00:09.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (PCI express gpp port H) 00:0a.0 PCI bridge: ATI Technologies Inc RD890 PCI to PCI bridge (external gfx1 port A) 00:11.0 SATA controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 SATA Controller [IDE mode] (rev 40) 00:12.0 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI0 Controller 00:12.2 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB EHCI Controller 00:13.0 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI0 Controller 00:13.2 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB EHCI Controller 00:14.0 SMBus: ATI Technologies Inc SBx00 SMBus Controller (rev 41) 00:14.1 IDE interface: ATI Technologies Inc SB7x0/SB8x0/SB9x0 IDE Controller (rev 40) 00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA) (rev 40) 00:14.3 ISA bridge: ATI Technologies Inc SB7x0/SB8x0/SB9x0 LPC host controller (rev 40) 00:14.4 PCI bridge: ATI Technologies Inc SBx00 PCI to PCI Bridge (rev 40) 00:14.5 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI2 Controller 00:15.0 PCI bridge: ATI Technologies Inc Device 43a0 00:16.0 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB OHCI0 Controller 00:16.2 USB Controller: ATI Technologies Inc SB7x0/SB8x0/SB9x0 USB EHCI Controller 00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor Link Control 01:00.0 VGA compatible controller: ATI Technologies Inc Juniper [Radeon HD 5700 Series] 01:00.1 Audio device: ATI Technologies Inc Juniper HDMI Audio [Radeon HD 5700 Series] 02:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) 05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) 07:00.0 SATA controller: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 03) 07:00.1 IDE interface: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 03) 08:0e.0 FireWire (IEEE 1394): Texas Instruments TSB43AB23 IEEE-1394a-2000 Controller (PHY/Link) 09:00.0 SATA controller: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 02) 09:00.1 IDE interface: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller (rev 02) Here is my sudo lshw -class network: *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:05:00.0 logical name: eth0 version: 03 serial: 6c:f0:49:e7:72:e8 size: 10Mbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:40 ioport:9e00(size=256) memory:fceff000-fcefffff memory:fcef8000-fcefbfff memory:fce00000-fce1ffff *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:06:00.0 logical name: eth1 version: 03 serial: 6c:f0:49:e7:72:ea size: 10Mbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:47 ioport:8e00(size=256) memory:fddff000-fddfffff memory:fddf8000-fddfbfff memory:fdd00000-fdd1ffff

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  • wifi hardware switch doesn't work on a Dell 1018

    - by user42566
    I have a problem with my Dell 1018 Inspiron. I can't switch the wifi on, through the key on the keyboard. I think it's a driver problem since Ubuntu 11.10. This are the versions i tried: Ubuntu 10.04 / 10.10 It's possible to install the driver by hand: sudo add-apt-repository ppa:lexical/hwe-wireless sudo apt-get update sudo apt-get install rtl8192ce-dkms Ubuntu 11.04 It works out of the box Ubuntu 11.10 / 12.04 I haven’t found any solution for these versions. The "ppa:lexical/hwe-wireless" doesn't work for these versions. It says Can not find package rtl8192ce-dkms. The window of additional drivers is empty. So I can't install the driver. The wired network works good. Here is some information: 0: dell-wifi: Wireless LAN Soft blocked: no Hard blocked: no 1: phy0: Wireless LAN Soft blocked: no Hard blocked: yes sudo lshw -class network *-network description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:05:00.0 logical name: eth0 version: 05 serial: 5c:26:0a:0d:20:10 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8105e-1.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:43 ioport:2000(size=256) memory:f0f2c000-f0f2cfff memory:f0f18000-f0f1bfff *-network description: Wireless interface product: RTL8188CE 802.11b/g/n WiFi Adapter vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:07:00.0 logical name: wlan0 version: 01 serial: 70:f1:a1:fe:15:bd width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=rtl8192ce driverversion=3.2.0-22-generic-pae firmware=N/A ip=192.168.1.76 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 ioport:3000(size=256) memory:f0100000-f0103fff mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ sudo lspci -nn 00:00.0 Host bridge [0600]: Intel Corporation N10 Family DMI Bridge [8086:a010] 00:02.0 VGA compatible controller [0300]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a011] 00:02.1 Display controller [0380]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a012] 00:1b.0 Audio device [0403]: Intel Corporation N10/ICH 7 Family High Definition Audio Controller [8086:27d8] (rev 02) 00:1c.0 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 1 [8086:27d0] (rev 02) 00:1c.1 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 2 [8086:27d2] (rev 02) 00:1d.0 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 [8086:27c8] (rev 02) 00:1d.1 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 [8086:27c9] (rev 02) 00:1d.2 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 [8086:27ca] (rev 02) 00:1d.3 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 [8086:27cb] (rev 02) 00:1d.7 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller [8086:27cc] (rev 02) 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev e2) 00:1f.0 ISA bridge [0601]: Intel Corporation NM10 Family LPC Controller [8086:27bc] (rev 02) 00:1f.2 SATA controller [0106]: Intel Corporation N10/ICH7 Family SATA Controller [AHCI mode] [8086:27c1] (rev 02) 00:1f.3 SMBus [0c05]: Intel Corporation N10/ICH 7 Family SMBus Controller [8086:27da] (rev 02) 05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05) 07:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01) mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 174f:1127 Syntek mark@mark-Inspiron-1018:~$

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  • Single page not appearing in Google Search

    - by Dan
    Description I have a static franchise website which has various sub pages each dedicated to an individual franchisee. For each franchisee the page, the only thing slightly similar between all of them are the page titles, they follow this structure: <title> Welcome to THE_COMPANY - PRODUCT_DESCRIPTION Services, THE_LOCATION </title> THE_COMPANY and PRODUCT_DESCRIPTION are the same across all franchisees, however THE_LOCATION changes depeding on where they are located in the UK. Each franchisee page has the following <meta /> tags: <meta name="DC.creator" content="user"/> <meta name="DC.format" content="text/html"/> <meta name="DC.language" content="en"/> <meta name="DC.date.modified" content="2014-01-23T11:22:31+00:00"/> <meta name="DC.date.created" content="2014-01-23T11:22:09+00:00"/> <meta name="DC.type" content="Page"/> <meta name="DC.distribution" content="Global"/> <meta name="robots" content="ALL"/> <meta name="distribution" content="Global"/> The main content on each franchisee page is completely different. The Problem There is one particular franchisee page, located in Area A.. Which will not appear in Google Search results at all. However every single other franchisee (if you Google Search for "THE_COMPANY, THE_LOCATION" is number 1). And if I do the same search on Bing, Yahoo or DuckDuckGo, the Area A franchisee is the first result on all of them. Has Google for some reason black listed one page on the site? What I Have Tried Ensuring the page is referenced in my sitemap.xml file 'Fetching as Google Bot' the link www.the_company.co.uk/areaa When that came back as OK I would submit to index Resubmitting the sitemap.xml file in Webmaster Tools Linking to the Area A page from another pages content For this I also waited about 3 weeks before checking again to give Google time to re-index Making a change to the page content and waiting another 2 / 3 weeks Removing the page completely and recreating it with an alternative URL The closest thing I have found to this issue is this StackOverflow question but this particular franchisee has existed for almost a year, it used to appear on Google searches however no longer does. I'm guessing the Panda update wasn't too happy with something on the page, but it hasn't effected anything else on the site and I am at a loss for things to try. I would greatly appreciate any information or thoughts as to what could have caused this Thanks. Update In line with Daniel Fukudas answer below, I have followed some of his steps but everything seems to check out alright: HTTP Headers HTTP/1.1 200 OK => Date => Tue, 25 Feb 2014 16:31:29 GMT Server => Zope/(2.12.16, python 2.6.6, linux2) ZServer/1.1 Content-Length => 40078 Expires => Sat, 01 Jan 2000 00:00:00 GMT Content-Type => text/html;charset=utf-8 Content-Language => en Vary => Accept-Encoding Connection => close Robots <meta /> tag: <meta name="robots" content="ALL"/> I have updated this <meta /> tag to read content="INDEX" instead now. robots.txt: User-agent: * Disallow: User-Agent: Googlebot Disallow: /*sendto_form$ Disallow: /*folder_factories$ Using site:THE_COMPANY.co.uk: Searching for 'AREA A site:THE_COMPANY.co.uk' does not return the page, but regardless of that searching just for site:THE_COMPANY.co.uk will not necessarily return every indexed page, or so I understand... Update It appears Google likes to drop pages every now and then from the index, despite my steps above, I left the site alone and the page appeared back in the SERPs by itself.

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  • Rails link to PDF version of show.html.erb

    - by Danny McClelland
    Hi Everyone, I have created a pdf version of our rails application using the Prawn plugin, the page in question is part of the Kase model - the link to the kase is /kases/1 and the link to the pdf version is /kases/1.pdf. How can I add a link within the show.html.erb to the PDF file so whichever page is being viewed it updates the URL to the correct case id? <% content_for :header do -%> <%=h @kase.jobno %> | <%=h @kase.casesubject %> <% end -%> <!-- #START SIDEBAR --> <% content_for :sidebar do -%> <% if @kase.avatar.exists? then %> <%= image_tag @kase.avatar.url %> <% else %> <p style="font-size:smaller"> You can upload an icon for this case that will display here. Usually this would be for the year number icon for easy recognition.</p> <% end %> <% end %> <!-- #END SIDEBAR --> <ul id="kases_showlist"> <li>Date Instructed: <span><%=h @kase.dateinstructed %></span></li> <li>Client Company: <span><%=h @kase.clientcompanyname %></span></li> <li>Client Reference: <span><%=h @kase.clientref %></span></li> <li>Case Subject: <span><%=h @kase.casesubject %></span></li> <li>Transport<span><%=h @kase.transport %></span></li> <li>Goods<span><%=h @kase.goods %></span></li> <li>Case Status: <span><%=h @kase.kase_status %></span></li> <li>Client Company Address: <span class="address"><%=h @kase.clientcompanyaddress %></span></li> <li>Client Company Fax: <span><%=h @kase.clientcompanyfax %></span></li> <li>Case Handler: <span><%=h @kase.casehandlername %></span></li> <li>Case Handler Tel: <span><%=h @kase.casehandlertel %></span></li> <li>Case Handler Email: <span><%=h @kase.casehandleremail %></span></li> <li>Claimant Name: <span><%=h @kase.claimantname %></span></li> <li>Claimant Address: <span class="address"><%=h @kase.claimantaddress %></span></li> <li>Claimant Contact: <span><%=h @kase.claimantcontact %></span></li> <li>Claimant Tel: <span><%=h @kase.claimanttel %></span></li> <li>Claiment Mob: <span><%=h @kase.claimantmob %></span></li> <li>Claiment Email: <span><%=h @kase.claimantemail %></span></li> <li>Claimant URL: <span><%=h @kase.claimanturl %></span></li> <li>Comments: <span><%=h @kase.comments %></span></li> </ul> <!--- START FINANCE INFORMATION --> <div id="kase_finances"> <div class="js_option"> <h2>Financial Options</h2><p class="finance_showhide"><%= link_to_function "Show","Element.show('finance_showhide');" %> / <%= link_to_function "Hide","Element.hide('finance_showhide');" %></p> </div> <div id="finance_showhide" style="display:none"> <ul id="kases_new_finance"> <li>Invoice Number<span><%=h @kase.invoicenumber %></span></li> <li>Net Amount<span><%=h @kase.netamount %></span></li> <li>VAT<span><%=h @kase.vat %></span></li> <li>Gross Amount<span><%=h @kase.grossamount %></span></li> <li>Date Closed<span><%=h @kase.dateclosed %></span></li> <li>Date Paid<span><%=h @kase.datepaid %></span></li> </ul></div> </div> <!--- END FINANCE INFORMATION --> <%= link_to 'Edit Case', edit_kase_path(@kase) %> | <%= link_to 'Back', kases_path %> | <a href="#">Top</a> <div style="width:120%; height: 50px; background-color: black; margin: 10px 0 0 -19px; padding: 0; background-color: #d4d4d4;">&nbsp;</div> <div class="js_option_kaseemails"> <%= link_to_function "Show", "Element.show('newinstructionemail1');" %> / <%= link_to_function "Hide", "Element.hide('newinstructionemail1');" %> </div> <h3>New Instruction Email</h3> <div id="newinstructionemail1" style="display:none"> <p class="kase_email_output"> Hi,<br /> <br /> Many thanks for your instructions in the subject matter.<br /> <br /> We have allocated reference number <%=h @kase.jobno %> to the above claim.<br /> <br /> We have started our inquiries and will be in touch.<br /> <br /> Best Regards,<br /> <br /> <strong><%=h current_user.name %></strong> <br /> McClelland &amp; Co<br /> PO Box 149<br /> Southport<br /> PR8 4GZ<br /> <br /> Tel: +(0) 1704 569871<br /> Fax: +(0) 1704 562234<br /> Mob: <%=h current_user.mobile %><br /> E-mail: <%= current_user.email %><br /> <br /> This e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you receive this e-mail in error please notify the originator of the message. <br /><br /> McClelland &amp; Co has taken every reasonable precaution to ensure that any attachment to this e-mail has been checked for viruses but it is strongly recommended that you carry out your own virus check before opening any attachment. McClelland &amp; Co cannot accept liability for any damage sustained as a result of software virus infection. </p> <%= link_to 'Edit Case', edit_kase_path(@kase) %> | <%= link_to 'Back', kases_path %> | <a href="#">Top</a> </div> <div style="width:120%; height: 20px; background-color: black; margin: 10px 0 0 -19px; padding: 0; background-color: #d4d4d4;">&nbsp;</div> <div class="js_option_kaseemails"> <%= link_to_function "Show", "Element.show('newinstructionemail');" %> / <%= link_to_function "Hide", "Element.hide('newinstructionemail');" %> </div> <h3>New Instruction Email</h3> <div id="newinstructionemail" style="display:none"> <p class="kase_email_output"> Hi,<br /> <br /> Many thanks for your instructions in the subject matter.<br /> <br /> We have allocated reference number <%=h @kase.jobno %> to the above claim.<br /> <br /> We have started our inquiries and will be in touch.<br /> <br /> Best Regards,<br /> <br /> <strong><%=h current_user.name %></strong> <br /> McClelland &amp; Co<br /> PO Box 149<br /> Southport<br /> PR8 4GZ<br /> <br /> Tel: +(0) 1704 569871<br /> Fax: +(0) 1704 562234<br /> Mob: <%=h current_user.mobile %><br /> E-mail: <%= current_user.email %><br /> <br /> This e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you receive this e-mail in error please notify the originator of the message. <br /><br /> McClelland &amp; Co has taken every reasonable precaution to ensure that any attachment to this e-mail has been checked for viruses but it is strongly recommended that you carry out your own virus check before opening any attachment. McClelland &amp; Co cannot accept liability for any damage sustained as a result of software virus infection. </p> <%= link_to 'Edit Case', edit_kase_path(@kase) %> | <%= link_to 'Back', kases_path %> | <a href="#">Top</a> </div> <div style="width:120%; height: 20px; background-color: black; margin: 10px 0 0 -19px; padding: 0; background-color: #d4d4d4;">&nbsp;</div> <div class="js_option_kaseemails"> <%= link_to_function "Show", "Element.show('newinstructionemail2');" %> / <%= link_to_function "Hide", "Element.hide('newinstructionemail2');" %> </div> <h3>New Instruction Email</h3> <div id="newinstructionemail2" style="display:none;"> <p class="kase_email_output"> Hi,<br /> <br /> Many thanks for your instructions in the subject matter.<br /> <br /> We have allocated reference number <%=h @kase.jobno %> to the above claim.<br /> <br /> We have started our inquiries and will be in touch.<br /> <br /> Best Regards,<br /> <br /> <strong><%=h current_user.name %></strong> <br /> McClelland &amp; Co<br /> PO Box 149<br /> Southport<br /> PR8 4GZ<br /> <br /> Tel: +(0) 1704 569871<br /> Fax: +(0) 1704 562234<br /> Mob: <%=h current_user.mobile %><br /> E-mail: <%= current_user.email %><br /> <br /> This e-mail and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you receive this e-mail in error please notify the originator of the message. <br /><br /> McClelland &amp; Co has taken every reasonable precaution to ensure that any attachment to this e-mail has been checked for viruses but it is strongly recommended that you carry out your own virus check before opening any attachment. McClelland &amp; Co cannot accept liability for any damage sustained as a result of software virus infection. </p> <%= link_to 'Edit Case', edit_kase_path(@kase) %> | <%= link_to 'Back', kases_path %> | <a href="#">Top</a> </div> Thanks, Danny

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  • In .net what are the difference between Eventlog and ManagementObject for retriving logs from remote

    - by Mitesh Patel
    I have found out following two ways for getting Application Event log entries from remote server. 1. Using EventLog object string logType = "Application"; EventLog ev = new EventLog(logType,"rspl200"); EventLogEntryCollection evColl = ev.Entries 2. Using ManagementObjectSearcher object ConnectionOptions co = new ConnectionOptions(); co.Username = "testA"; co.Password = "testA"; ManagementScope scope = new ManagementScope(@"\" + "machineName"+ @"\root\cimv2", co); scope.Connect(); SelectQuery query = new SelectQuery(@"select * from Win32_NtLogEvent"); EnumerationOptions opt = new EnumerationOptions(); opt.BlockSize = 1000; using (ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query,opt)) { foreach (ManagementObject mo in searcher.Get()) { // write down log entries Console.Writeline(mo["EventCode"]); } } I can easily get remote eventlog using method #1 (Using EventLog object) without any security access denied exception. But using method #2 (Using ManagementObjectSearcher object) i get access denied exception. Actually I want remote event log (only application and also latest log not all application logs) to be displayed in treeview like below - ServerName - Logs + Error + Information + Warning Can anybody help me in this to find out best way from this or any other? Also the main thing is that user who reads remote logs may be in different domain than server. Thanks Mitesh Patel

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  • Hyperlink regex including http(s):// not working in C#

    - by Rory Fitzpatrick
    I think this is sufficiently different from similar questions to warrant a new one. I have the following regex to match the beginning hyperlink tags in HTML, including the http(s):// part in order to avoid mailto: links <a[^>]*?href=[""'](?<href>\\b(https?)://[^\[\]""]+?)[""'][^>]*?> When I run this through Nregex (with escaping removed) it matches correctly for the following test cases: <a href="http://www.bbc.co.uk"> <a href="http://bbc.co.uk"> <a href="https://www.bbc.co.uk"> <a href="mailto:[email protected]"> However when I run this in my C# code it fails. Here is the matching code: public static IEnumerable<string> GetUrls(this string input, string matchPattern) { var matches = Regex.Matches(input, matchPattern, RegexOptions.Compiled | RegexOptions.IgnoreCase); foreach (Match match in matches) { yield return match.Groups["href"].Value; } } And my tests: @"<a href=""https://www.bbc.co.uk"">bbc</a>".GetUrls(StringExtensions.HtmlUrlRegexPattern).Count().ShouldEqual(1); @"<a href=""mailto:[email protected]"">bbc</a>".GetUrls(StringExtensions.HtmlUrlRegexPattern).Count().ShouldEqual(0); The problem seems to be in the \\b(https?):// part which I added, removing this passes the normal URL test but fails the mailto: test. Anyone shed any light?

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  • Overlapping matches with finditer() in Python

    - by Raphink
    Hi there, I'm using a regex to match Bible verse references in a text. The current regex is REF_REGEX = re.compile(r'(?<!\w)((?i)q(?:uote)?\s+)?((?:(?:[1-3]|I{1,3})\s*)?[A-Za-z]+)\.?(?:\s*(\d+)(?:[:.](\d+)(?:-(\d+))?)?)(?:\s+(?:(?i)(?:from\s+)|(?:in\s+)|(?P<lbrace>\())\s*(\w+)(?(lbrace)\)))?', re.UNICODE) This matches the following expressions fine: "jn 3:16": (None, 'jn', '3', '16', None, None, None), "matt. 18:21-22": (None, 'matt', '18', '21', '22', None, None), "q matt. 18:21-22": ('q ', 'matt', '18', '21', '22', None, None), "QuOTe jn 3:16": ('QuOTe ', 'jn', '3', '16', None, None, None), "q 1co13:1": ('q ', '1co', '13', '1', None, None, None), "q 1 co 13:1": ('q ', '1 co', '13', '1', None, None, None), "quote 1 co 13:1": ('quote ', '1 co', '13', '1', None, None, None), "quote 1co13:1": ('quote ', '1co', '13', '1', None, None, None), "jean 3:18 (PDV)": (None, 'jean', '3', '18', None, '(', 'PDV'), "quote malachie 1.1-2 fRom Colombe": ('quote ', 'malachie', '1', '1', '2', None, 'Colombe'), "quote malachie 1.1-2 In Colombe": ('quote ', 'malachie', '1', '1', '2', None, 'Colombe'), "cinq jn 3:16 (test)": (None, 'jn', '3', '16', None, '(', 'test'), "Q IIKings5.13-58 from wolof": ('Q ', 'IIKings', '5', '13', '58', None, 'wolof'), "This text is about lv5.4-6 in KJV only": (None, 'lv', '5', '4', '6', None, 'KJV'), but it fails to parse: "Found in 2 Cor. 5:18-21 ( Ministers": (None, '2 Cor', '5', '18', '21', None, None), because it returns (None, 'in', '2', None, None, None, None) instead. Is there a way to get finditer() to return all matches, even if they overlap, or is there a way to improve my regex so it matches this last bit properly? Thanks.

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  • How to parse rss from a php page, using jQuery/jFeed?

    - by ricebowl
    I'm trying to fumble my way through parsing rss sensibly, using jQuery and jFeed. Because of the same origin policy I'm pulling the BBC's health news feed into a local page (http://www.davidrhysthomas.co.uk/play/proxy.php). Originally this was just the same proxy.php script as available in the jFeed download package, but due to my host's disabling allow_url_fopen() I've amended the php to the following: $url = "http://newsrss.bbc.co.uk/rss/newsonline_uk_edition/health/rss.xml"; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $data = curl_exec($ch); echo "$data"; curl_close($ch); Which seems to generate the same/comparable contents as the original fopen on my local machine. Now that seems to be working, I'm looking at setting the jFeed script up to work with the page and, to my embarrassment, don't see how. I understand that, at the least, this should work: jQuery.getFeed({ url: 'http://www.davidrhysthomas.co.uk/play/proxy.php', success: function(feed) { alert(feed.title); } }); ...but, as I'm sure you anticipate, it doesn't. What non-output there is, is available for your perusal here: http://www.davidrhysthomas.co.uk/play/exampleTest.html. And I honestly don't have a clue what to do about it. If anyone could offer some pointers, tips, hints, or, at a pinch, a quick slap around the cheeks and a 'pull yourself together!' it'd be much appreciated... Thanks in advance =)

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  • PHP - dynamic page via subdomain

    - by Phil Jackson
    Hi, im creating profile pages based on a subdomains using the wildcard DNS setting. Problem being, if the subdomain is incorrect, I want it to redirect to the same page but without the subdomain infront ie; if ( preg_match('/^(www\.)?([^.]+)\.domainname\.co.uk$/', $_SERVER['HTTP_HOST'], $match)) { $DISPLAY_NAME = $match[2]; $query = "SELECT * FROM `" . ACCOUNT_TABLE . "` WHERE DISPLAY_NAME = '$DISPLAY_NAME' AND ACCOUNT_TYPE = 'premium_account'"; $q = mysql_query( $query, $CON ) or die( "_error_" . mysql_error() ); if( mysql_num_rows( $q ) != 0 ) { }else{ mysql_close( $CON ); header("location: http://www.domainname.co.uk"); exit; } } I get a browser error: Firefox has detected that the server is redirecting the request for this address in a way that will never complete. I think its because when using header("location: http://www.domainname.co.uk"); it still puts the sub domain infront i.e. ; header("location: http://www.sub.domainname.co.uk"); Does anyone know how to sort this and/or what is the problem. Regards, Phil

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  • Reasoner Conversion Problems:

    - by Annalyne
    I have this code right here in Java and I wanted to translate it in C++, but I had some problems going: this is the java code: import java.io.*; import java.util.*; public class ClueReasoner { private int numPlayers; private int playerNum; private int numCards; private SATSolver solver; private String caseFile = "cf"; private String[] players = {"sc", "mu", "wh", "gr", "pe", "pl"}; private String[] suspects = {"mu", "pl", "gr", "pe", "sc", "wh"}; private String[] weapons = {"kn", "ca", "re", "ro", "pi", "wr"}; private String[] rooms = {"ha", "lo", "di", "ki", "ba", "co", "bi", "li", "st"}; private String[] cards; public ClueReasoner() { numPlayers = players.length; // Initialize card info cards = new String[suspects.length + weapons.length + rooms.length]; int i = 0; for (String card : suspects) cards[i++] = card; for (String card : weapons) cards[i++] = card; for (String card : rooms) cards[i++] = card; numCards = i; // Initialize solver solver = new SATSolver(); addInitialClauses(); } private int getPlayerNum(String player) { if (player.equals(caseFile)) return numPlayers; for (int i = 0; i < numPlayers; i++) if (player.equals(players[i])) return i; System.out.println("Illegal player: " + player); return -1; } private int getCardNum(String card) { for (int i = 0; i < numCards; i++) if (card.equals(cards[i])) return i; System.out.println("Illegal card: " + card); return -1; } private int getPairNum(String player, String card) { return getPairNum(getPlayerNum(player), getCardNum(card)); } private int getPairNum(int playerNum, int cardNum) { return playerNum * numCards + cardNum + 1; } public void addInitialClauses() { // TO BE IMPLEMENTED AS AN EXERCISE // Each card is in at least one place (including case file). for (int c = 0; c < numCards; c++) { int[] clause = new int[numPlayers + 1]; for (int p = 0; p <= numPlayers; p++) clause[p] = getPairNum(p, c); solver.addClause(clause); } // If a card is one place, it cannot be in another place. // At least one card of each category is in the case file. // No two cards in each category can both be in the case file. } public void hand(String player, String[] cards) { playerNum = getPlayerNum(player); // TO BE IMPLEMENTED AS AN EXERCISE } public void suggest(String suggester, String card1, String card2, String card3, String refuter, String cardShown) { // TO BE IMPLEMENTED AS AN EXERCISE } public void accuse(String accuser, String card1, String card2, String card3, boolean isCorrect) { // TO BE IMPLEMENTED AS AN EXERCISE } public int query(String player, String card) { return solver.testLiteral(getPairNum(player, card)); } public String queryString(int returnCode) { if (returnCode == SATSolver.TRUE) return "Y"; else if (returnCode == SATSolver.FALSE) return "n"; else return "-"; } public void printNotepad() { PrintStream out = System.out; for (String player : players) out.print("\t" + player); out.println("\t" + caseFile); for (String card : cards) { out.print(card + "\t"); for (String player : players) out.print(queryString(query(player, card)) + "\t"); out.println(queryString(query(caseFile, card))); } } public static void main(String[] args) { ClueReasoner cr = new ClueReasoner(); String[] myCards = {"wh", "li", "st"}; cr.hand("sc", myCards); cr.suggest("sc", "sc", "ro", "lo", "mu", "sc"); cr.suggest("mu", "pe", "pi", "di", "pe", null); cr.suggest("wh", "mu", "re", "ba", "pe", null); cr.suggest("gr", "wh", "kn", "ba", "pl", null); cr.suggest("pe", "gr", "ca", "di", "wh", null); cr.suggest("pl", "wh", "wr", "st", "sc", "wh"); cr.suggest("sc", "pl", "ro", "co", "mu", "pl"); cr.suggest("mu", "pe", "ro", "ba", "wh", null); cr.suggest("wh", "mu", "ca", "st", "gr", null); cr.suggest("gr", "pe", "kn", "di", "pe", null); cr.suggest("pe", "mu", "pi", "di", "pl", null); cr.suggest("pl", "gr", "kn", "co", "wh", null); cr.suggest("sc", "pe", "kn", "lo", "mu", "lo"); cr.suggest("mu", "pe", "kn", "di", "wh", null); cr.suggest("wh", "pe", "wr", "ha", "gr", null); cr.suggest("gr", "wh", "pi", "co", "pl", null); cr.suggest("pe", "sc", "pi", "ha", "mu", null); cr.suggest("pl", "pe", "pi", "ba", null, null); cr.suggest("sc", "wh", "pi", "ha", "pe", "ha"); cr.suggest("wh", "pe", "pi", "ha", "pe", null); cr.suggest("pe", "pe", "pi", "ha", null, null); cr.suggest("sc", "gr", "pi", "st", "wh", "gr"); cr.suggest("mu", "pe", "pi", "ba", "pl", null); cr.suggest("wh", "pe", "pi", "st", "sc", "st"); cr.suggest("gr", "wh", "pi", "st", "sc", "wh"); cr.suggest("pe", "wh", "pi", "st", "sc", "wh"); cr.suggest("pl", "pe", "pi", "ki", "gr", null); cr.printNotepad(); cr.accuse("sc", "pe", "pi", "bi", true); } } how can I convert this? there are too many errors I get. for my C++ code (as a commentor asked for) #include <iostream> #include <cstdlib> #include <string> using namespace std; void Scene_Reasoner() { int numPlayer; int playerNum; int cardNum; string filecase = "Case: "; string players [] = {"sc", "mu", "wh", "gr", "pe", "pl"}; string suspects [] = {"mu", "pl", "gr", "pe", "sc", "wh"}; string weapons [] = {"kn", "ca", "re", "ro", "pi", "wr"}; string rooms[] = {"ha", "lo", "di", "ki", "ba", "co", "bi", "li", "st"}; string cards [0]; }; void Scene_Reason_Base () { numPlayer = players.length; // Initialize card info cards = new String[suspects.length + weapons.length + rooms.length]; int i = 0; for (String card : suspects) cards[i++] = card; for (String card : weapons) cards[i++] = card; for (String card : rooms) cards[i++] = card; cardNum = i; }; private int getCardNum (string card) { for (int i = 0; i < numCards; i++) if (card.equals(cards[i])) return i; cout << "Illegal card: " + card <<endl; return -1; }; private int getPairNum(String player, String card) { return getPairNum(getPlayerNum(player), getCardNum(card)); }; private int getPairNum(int playerNum, int cardNum) { return playerNum * numCards + cardNum + 1; }; int main () { return 0; }

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  • Troubleshooting an unstable internet connection

    - by Konrad Rudolph
    My MacBook Pro running OS X (10.9, but I had the same problem before) is connected to a Belkin router via WiFi and, using Virgin Media as the ISP, to the internet. The connection is extremely unstable – on some days, I get a ping timeout every few seconds. In addition, some domains seem to suffer general connectivity issues. For instance, I often find that while the youtube.com website loads, none of the videos (which are hosted on a separate domain) do. At other times, videos load but always fail to buffer, even though the actual connection speed is ok, even though I’ve disabled dash playback. Since I’m living in a rented room and the ISP contract isn’t actually mine I’ve got only limited possibilities of addressing the problem. In particular, I have no access to the router configuration and my non tech savvy landlady, while sympathetic, is not in a great hurry to hand the problem over to the ISP’s customer support. What’s more, I seem to be the only person in the house experiencing these problems – but I can imagine that this is simply because I’m the only one who’s using the internet continuously. I’m searching for specific tests that might be able to pinpoint – and ideally solve – the problem. So far all I’ve managed to do is establish that Virgin is routing my traffic in mysterious ways. Here’s an excerpt from traceroute google.co.uk. It’s worth mentioning that the host name doesn’t seem to matter a lot, the trace route is always the same. traceroute: Warning: google.co.uk has multiple addresses; using 62.254.36.148 traceroute to google.co.uk (62.254.36.148), 64 hops max, 52 byte packets 1 (192.168.2.1) 1.112 ms 1.300 ms 2.359 ms 2 10.100.32.1 (10.100.32.1) 11.926 ms 10.217 ms 24.987 ms 3 cmbg-core-1a-ae3-610.network.virginmedia.net (80.1.202.93) 28.809 ms * 66.653 ms 4 popl-bb-1b-ae16-0.network.virginmedia.net (212.43.163.141) 13.759 ms 126.504 ms 20.472 ms 5 nrth-bb-1b-et-010-0.network.virginmedia.net (62.253.175.57) 28.357 ms 16.398 ms 42.387 ms 6 nrth-bb-1c-ae1-0.network.virginmedia.net (62.253.174.110) 27.441 ms 15.622 ms 12.044 ms 7 lutn-icdn-1-ae0-0.network.virginmedia.net (62.253.175.82) 16.678 ms 28.463 ms 28.253 ms 8 * * * 9 * * * 10 * * * ^C If I let it, this goes on until the end of time. It never seems to reach a destination. Is this normal? A friend living in the same town who is also with Virgin Media has a more conventional traceroute output: 7 hops to google.co.uk, all of which send the ICMP TIME_EXCEEDED response. The obvious fix – rebooting the router – doesn’t seem to help. As far as I can tell, the WiFi connection is stable (I can always ping the router) so the problem is further downstream. I’ve tried using an alternative DNS before (OpenDNS) but if anything, this made things worse. In fact, it made all Google services nigh unreachable.

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  • Change the default Google search domain [closed]

    - by Anoop
    Possible Duplicate: Firefox 3.6 - Navigation Toolbar - Google search box language problem I am currently working from Germany. From Firefox, if I give something to search in the Google search box in the browser, it is automatically taking me to google.de, and is returning results which is of no use for me. Is there any chance, that I can change the default to google.com or google.co.in or google.co.uk, something like that which gives me English results?

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  • Fonts on Certain Web Pages jagged and blocky on XP yet fine in Windows7

    - by Peter Nimmo
    This site for example: http://www.cultbox.co.uk/reviews/episodes/778-twenty-twelve-episode-3-review Which has this CSS - http://www.cultbox.co.uk/style.css body { text-align: center; font-size: 1em; font-family: Helvetica Neue,Helvetica,Arial,sans-serif; color: #000000; background: #D3D8E1; } I think I first saw this problem on Tech Republic. Also is it possible to find out which Font the browser chose to render in?

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  • fan adapter required for 2 controlers

    - by spy
    good day i would like to ask if i can connect the same fan to 2 fan controllers at the same time, if so how do i go about it please, i bought http://www.ebay.co.uk/itm/121255084003?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 wich has a loger cable and sits on my table and http://www.ebay.co.uk/itm/111365380971?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 sits in the tower and facing away from me.

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  • amazon ec2 ubuntu with gitlab and nginx - cant load?

    - by thebluefox
    Ok, so I've spooled up an Amazon EC2 server running Ubuntu, and then followed the instructions below to install GitLab; http://doc.gitlab.com/ce/install/installation.html The only step I've not been able to complete is running the following check on the status; sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production I get the following error; rake aborted! Errno::ENOMEM: Cannot allocate memory - whoami Which I presume is becuase my EC2 is just running a free tier setup, so isn't that well spec'd. Regardless, I've been trying to access this through my browser. I've set up the elastic IP and pointed my domain at it (for the purpose of this, lets say its git.mydom.co.uk). Doing a whois on this domain shows me its pointing to the right place. For some reason though, I get the "Oops, Chrome could not connect to git.mydom.co.uk". Now - for a period of time I was getting the Nginx holding page (telling me I still needed to perform configuration). This though disappeared after removing the default file from /etc/nginx/sites-enabled/ (after reading this could be issue on a troubleshooting page). Since then, I've had nothing, even when I symlinked the file back in from /sites-available. I've tried changing the owner of the git.mydom.co.uk file sat inside /sites-enabled and /sites-available to www-data, as suggested here, but I could only change the permission of the file in /sites-available, and not the symlinked one in /sites-enabled. The content of this file is as follows; upstream gitlab { server unix:/home/git/gitlab/tmp/sockets/gitlab.socket; } server { listen *:80 default_server; # e.g., listen 192.168.1.1:80; In most cases *:80 is a good idea server_name git.mydom.co.uk; # e.g., server_name source.example.com; server_tokens off; # don't show the version number, a security best practice root /home/git/gitlab/public; # Increase this if you want to upload large attachments # Or if you want to accept large git objects over http client_max_body_size 20m; # individual nginx logs for this gitlab vhost access_log /var/log/nginx/gitlab_access.log; error_log /var/log/nginx/gitlab_error.log; location / { # serve static files from defined root folder;. # @gitlab is a named location for the upstream fallback, see below try_files $uri $uri/index.html $uri.html @gitlab; } All the paths mentioned in here look ok...I'm about at the end of my knowledge now!

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  • Domain Forwarding | A Magento Store

    - by WaZ
    I have installed Magento inside a folder called magento. The URL of the site currently looks like this: http://gios.azamdevelopment.co.uk/magento/ We want our domain forwarded to the above URL and moreover, any links relative should work as well. e.g. http://gios.azamdevelopment.co.uk/magento/customer/account/login/ should ideally be www.giosconcept.com/customer/account/login and so forth. Thanks very much.

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  • Domain Forwarding | A Magento Store

    - by WaZ
    I have installed Magento inside a folder called magento. The URL of the site currently looks like this: http://gios.azamdevelopment.co.uk/magento/ We want our domain forwarded to the above URL and moreover, any links relative should work as well. e.g. http://gios.azamdevelopment.co.uk/magento/customer/account/login/ should ideally be www.giosconcept.com/customer/account/login and so forth. Thanks very much.

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  • CSS Dropdown Menu issues

    - by Simon Hume
    Can anyone help with a small problem. I've got a nice simple CSS dropdown menu http://www.cinderellahair.co.uk/new/CSSDropdown.html The problem I have is when you rollover a menu item that has children which are wider than the content, it pushes the whole menu right. Aside of shortening the child menu links down, is there any tweak I can make to my CSS to stop this happening? CSS Code: /* General */ #cssdropdown, #cssdropdown ul { list-style: none; } #cssdropdown, #cssdropdown * { padding: 0; margin: 0; } #cssdropdown {padding:43px 0px 0px 0px;} /* Head links */ #cssdropdown li.headlink { margin:0px 40px 0px -1px; float: left; background-color: #e9e9e9;} #cssdropdown li.headlink a { display: block; padding: 0px 0px 0px 5px; text-decoration:none; } #cssdropdown li.headlink a:hover { text-decoration:underline; } /* Child lists and links */ #cssdropdown li.headlink ul { display: none; text-align: left; padding:10px 0px 0px 0px; font-size:12px; float:left;} #cssdropdown li.headlink:hover ul { display: block; } #cssdropdown li.headlink ul li a { padding: 5px; height: 17px; } #cssdropdown li.headlink ul li a:hover { background-color: #333; } /* Pretty styling */ body { font-family:Georgia, "Times New Roman", Times, serif; font-size: 16px; } #cssdropdown a { color: grey; } #cssdropdown ul li a:hover { text-decoration: none; } #cssdropdown li.headlink { background-color: white; } #cssdropdown li.headlink ul { padding-bottom: 10px;} HTML: <ul id="cssdropdown"> <li class="headlink"><a href="http://www.cinderellahair.co.uk/new/index.php">HOME</a></li> <li class="headlink"><a href="http://www.cinderellahair.co.uk/new/gallery/gallery.php">GALLERY</a> <ul> <li><a href="http://amazon.com/">CELEBRITY</a></li> <li><a href="http://ebay.com/">BEFORE &amp; AFTER</a></li> <li><a href="http://craigslist.com/">HAIR TYPES</a></li> </ul> </li> <li class="headlink"><a href="http://www.cinderellahair.co.uk/new/about-cinderella-hair-extensions/about-us.php">ABOUT US</a> <ul> <li><a href="http://amazon.com/">WHY CHOOSE CINDERELLA</a></li> <li><a href="http://ebay.com/">TESTIMONIALS</a></li> <li><a href="http://craigslist.com/">MINI VIDEO CLIPS</a></li> <li><a href="http://craigslist.com/">OUR HAIR PRODUCTS</a></li> </ul> </li> <li class="headlink"><a href="http://www.cinderellahair.co.uk/new/news-and-offers/news.php">NEWS &amp; OFFERS</a> <ul> <li><a href="http://amazon.com/">VERA WANG FREE GIVEAWAY</a></li> <li><a href="http://ebay.com/">CINDERELLA ON TV</a></li> <li><a href="http://craigslist.com/">CINDERELLA IN THE PRESS</a></li> <li><a href="http://craigslist.com/">CINDRELLA NEWSLETTERS</a></li> </ul> </li> <li class="headlink"><a href="http://www.cinderellahair.co.uk/new/cinderella-salon/salon-finder.php">SALON FINDER</a></li> </ul> JS Code: $(document).ready(function(){ $('#cssdropdown li.headlink').hover( function() { $('ul', this).css('display', 'block'); }, function() { $('ul', this).css('display', 'none'); }); }); Full code is on the link above, just view source.

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  • DefaultHttpClient GET and POST commands Java Android

    - by RenegadeAndy
    Ok this is my application : An Android app to allow me to submit CokeZone codes into CokeZone.co.uk from a mobile app instead of from the website. So I wrote this section of code to do the post logon command and then check to see if im logged in after. Problem is - the html I get from the homepage after I send the post command is the default - as if im not logged in - so something is going wrong. Can anyone please help! Its probably the URL im sending the POST to, or the params within the POST command - I havent done much of this stuff so its probably something obvious. Below is my code so far: DefaultHttpClient httpclient = new DefaultHttpClient(); HttpGet httpget = new HttpGet(url); HttpResponse response = httpclient.execute(httpget); HttpEntity entity = response.getEntity(); thisResponse = printPage(entity.getContent()); Log.e("debug",thisResponse); System.out.println("Login form get: " + response.getStatusLine()); if (entity != null) { entity.consumeContent(); } System.out.println("Initial set of cookies:"); List<Cookie> cookies = httpclient.getCookieStore().getCookies(); if (cookies.isEmpty()) { System.out.println("None"); } else { for (int i = 0; i < cookies.size(); i++) { System.out.println("- " + cookies.get(i).toString()); } } HttpPost httpost = new HttpPost("https://secure.cokezone.co.uk/home/blank.jsp?_DARGS=/home/login/login.jsp"); List <NameValuePair> nvps = new ArrayList <NameValuePair>(); nvps.add(new BasicNameValuePair("_dyncharset", "ISO-8859-1")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.loginFormBean.name","renegadeandy%40gmail.com")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.loginFormBean.name", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.cookiedUser", "false")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.cookiedUser", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.loginFormBean.password", "passwordval")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.loginFormBean.password", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.rememberMe", "yes")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.rememberMe", "false")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.aSuccessURL", "http://www.cokezone.co.uk/home/index.jsp")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.aSuccessURL", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.aErrorURL", "http://www.cokezone.co.uk/home/index.jsphttps://secure.cokezone.co.uk/home/index.jsp")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.aErrorURL", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.explicitLogin", "true")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.explicitLogin", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.fICLogin", "login")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.fICLogin", "+")); nvps.add(new BasicNameValuePair("/grlp/login/LoginHandler.fICLogin", "LOGIN")); nvps.add(new BasicNameValuePair("_D:/grlp/login/LoginHandler.fICLogin", "+")); nvps.add(new BasicNameValuePair("_DARGS", "/home/login/login.jsp")); httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8)); response = httpclient.execute(httpost); entity = response.getEntity(); System.out.println("Login form get: " + response.getStatusLine()); if (entity != null) { thisResponse = printPage(entity.getContent()); entity.consumeContent(); } Log.e("debug",thisResponse); Log.e("debug","done"); httpget = new HttpGet("http://www.cokezone.co.uk/home/index.jsp"); response = httpclient.execute(httpget); entity = response.getEntity(); TextView points = (TextView)findViewById(R.id.points); points.setText(getPoints(entity.getContent()).toString()); debug.setText(thisResponse); System.out.println("Post logon cookies:"); cookies = httpclient.getCookieStore().getCookies(); if (cookies.isEmpty()) { System.out.println("None"); } else { for (int i = 0; i < cookies.size(); i++) { System.out.println("- " + cookies.get(i).toString()); } }

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  • C# WMI Eventwatcher code stopped working on Windows 7 with security exception

    - by Flores
    This is code that worked fine on Windows XP for years. User is not local administrator. WqlEventQuery query = new WqlEventQuery("SELECT * FROM Win32_ProcessStopTrace"); ConnectionOptions co = new ConnectionOptions(); co.EnablePrivileges = true; ManagementEventWatcher watcher = new ManagementEventWatcher(new ManagementScope(@"root\cimv2",co), query); watcher.EventArrived += StopEventArrived; watcher.Start(); This throws an SecurityException on Windows 7, Access Denied when running as a non admin. On XP this works fine without being admin. On this link MS states that 'Windows 7: Low-integrity users have read-only permissions for local WMI operations.'. I guess this is the problem. But I can't find any clue on how to change this.

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  • Cannot access a web page? [closed]

    - by ipkiss
    Hello all, Recently, I could not access the webpage bbc.co.uk anymore, while I can access other websites smoothly. Ar first, I though there may be some problem with my laptop. However, if I use my laptop through my company network, I can load the page bbc.co.uk normally. Then, I though maybe my ADSL at home blocks that web address. However, I tried another laptop with my home ADSL and it can load the page bbc.co.uk very fast. Now I do not know what could be the problem. Can anyone tell me please? Thank you.

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  • Problem extracting text from RSS feeds

    - by Gautam
    Hi, I am new to the world of Ruby and Rails. I have seen rails cast 190 and I just started playing with it. I used selector gadget to find out the CSS and XPath I have the following code.. require 'rubygems' require 'nokogiri' require 'open-uri' url = "http://www.telegraph.co.uk/sport/football/rss" doc = Nokogiri::HTML(open(url)) doc.xpath('//a').each do |paragraph| puts paragraph.text end When I extracted text from a normal HTML page with css, I could get the extracted text on the console. But when I try to do the same either with CSS or XPath for the RSS Feed for the following URL mentioned in the code above, I dont get any output. How do you extract text from RSS feeds?? I also have another silly question. Is there a way to extract text from 2 different feeds and display it on the console something like url1 = "http://www.telegraph.co.uk/sport/football/rss" url2 = "http://www.telegraph.co.uk/sport/cricket/rss" Looking forward for your help and suggestions Thank You Gautam

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  • Facebook Share doesn't show my description or my thumbnail

    - by Drew
    I have followed every single piece of advice I have found to try to get this to work but all of it has been to no avail. Can someone tell me why my description/thumbnail doesn't show up? Thanks. Below is my code and the link to the site: Meta Tags: <meta name="title" content="La Vita è Bella, because life is beautiful" /> <meta name="description" content="Drawing on Italy’s most famous export – great-tasting, healthy, colourful food – La Vita é Bella brings families together to experience mealtimes the Italian way." /> <link rel="image_src" href="http://www.lavitaebella.co.uk/images/imageforfacebook.jpg" /> Actual Link: <a href="http://www.facebook.com/share.php?u=http://www.lavitaebella.co.uk" target="_blank"><img src='../images/share/s-fb.png' /></a> http://www.lavitaebella.co.uk/ Thanks in advance for any help.

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