Search Results

Search found 2155 results on 87 pages for 'mathematical expressions'.

Page 25/87 | < Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >

  • New regular expression features in PCRE 8.34 and 8.35

    - by Jan Goyvaerts
    PCRE 8.34 adds some new regex features and changes the behavior of a few to make it better compatible with the latest versions of Perl. There are no changes to the regex syntax in PCRE 8.35. \o{377} is now an octal escape just like \377. This syntax was first introduced in Perl 5.12. It avoids any confusion between octal escapes and backreferences. It also allows octal numbers beyond 377 to be used. E.g. \o{400} is the same as \x{100}. If you have any reason to use octal escapes instead of hexadecimal escapes then you should definitely use the new syntax. Because of this change, \o is now an error when it doesn’t form a valid octal escape. Previously \o was a literal o and \o{377} was a sequence of 337 o‘s. In free-spacing mode, whitespace between a quantifier and the ? that makes it lazy or the + that makes it possessive is now ignored. In Perl this has always been the case. In PCRE 8.33 and prior, whitespace ended a quantifier and any following ? or + was seen as a second quantifier and thus an error. The shorthand \s now matches the vertical tab character in addition to the other whitespace characters it previously matched. Perl 5.18 made the same change. Many other regex flavors have always included the vertical tab in \s, just like POSIX has always included it in [[:space:]]. Names of capturing groups are no longer allowed to start with a digit. This has always been the case in Perl since named groups were added to Perl 5.10. PCRE 8.33 and prior even allowed group names to consist entirely of digits. [[:<:]] and [[::]] are now treated as POSIX-style word boundaries. They match at the start and the end of a word. Though they use similar syntax, these have nothing to do with POSIX character classes and cannot be used inside character classes. Perl does not support POSIX word boundaries. The same changes affect PHP 5.5.10 (and later) and R 3.0.3 (and later) as they have been updated to use PCRE 8.34. RegexBuddy and RegexMagic have been updated to support the latest versions of PCRE, PHP, and R. Older versions that were previously supported are still supported, so you can compare or convert your regular expressions between the latest versions of PCRE, PHP, and R and whichever version you were using previously.

    Read the article

  • C#/.NET Little Wonders: The Useful But Overlooked Sets

    - by James Michael Hare
    Once again we consider some of the lesser known classes and keywords of C#.  Today we will be looking at two set implementations in the System.Collections.Generic namespace: HashSet<T> and SortedSet<T>.  Even though most people think of sets as mathematical constructs, they are actually very useful classes that can be used to help make your application more performant if used appropriately. A Background From Math In mathematical terms, a set is an unordered collection of unique items.  In other words, the set {2,3,5} is identical to the set {3,5,2}.  In addition, the set {2, 2, 4, 1} would be invalid because it would have a duplicate item (2).  In addition, you can perform set arithmetic on sets such as: Intersections: The intersection of two sets is the collection of elements common to both.  Example: The intersection of {1,2,5} and {2,4,9} is the set {2}. Unions: The union of two sets is the collection of unique items present in either or both set.  Example: The union of {1,2,5} and {2,4,9} is {1,2,4,5,9}. Differences: The difference of two sets is the removal of all items from the first set that are common between the sets.  Example: The difference of {1,2,5} and {2,4,9} is {1,5}. Supersets: One set is a superset of a second set if it contains all elements that are in the second set. Example: The set {1,2,5} is a superset of {1,5}. Subsets: One set is a subset of a second set if all the elements of that set are contained in the first set. Example: The set {1,5} is a subset of {1,2,5}. If We’re Not Doing Math, Why Do We Care? Now, you may be thinking: why bother with the set classes in C# if you have no need for mathematical set manipulation?  The answer is simple: they are extremely efficient ways to determine ownership in a collection. For example, let’s say you are designing an order system that tracks the price of a particular equity, and once it reaches a certain point will trigger an order.  Now, since there’s tens of thousands of equities on the markets, you don’t want to track market data for every ticker as that would be a waste of time and processing power for symbols you don’t have orders for.  Thus, we just want to subscribe to the stock symbol for an equity order only if it is a symbol we are not already subscribed to. Every time a new order comes in, we will check the list of subscriptions to see if the new order’s stock symbol is in that list.  If it is, great, we already have that market data feed!  If not, then and only then should we subscribe to the feed for that symbol. So far so good, we have a collection of symbols and we want to see if a symbol is present in that collection and if not, add it.  This really is the essence of set processing, but for the sake of comparison, let’s say you do a list instead: 1: // class that handles are order processing service 2: public sealed class OrderProcessor 3: { 4: // contains list of all symbols we are currently subscribed to 5: private readonly List<string> _subscriptions = new List<string>(); 6:  7: ... 8: } Now whenever you are adding a new order, it would look something like: 1: public PlaceOrderResponse PlaceOrder(Order newOrder) 2: { 3: // do some validation, of course... 4:  5: // check to see if already subscribed, if not add a subscription 6: if (!_subscriptions.Contains(newOrder.Symbol)) 7: { 8: // add the symbol to the list 9: _subscriptions.Add(newOrder.Symbol); 10: 11: // do whatever magic is needed to start a subscription for the symbol 12: } 13:  14: // place the order logic! 15: } What’s wrong with this?  In short: performance!  Finding an item inside a List<T> is a linear - O(n) – operation, which is not a very performant way to find if an item exists in a collection. (I used to teach algorithms and data structures in my spare time at a local university, and when you began talking about big-O notation you could immediately begin to see eyes glossing over as if it was pure, useless theory that would not apply in the real world, but I did and still do believe it is something worth understanding well to make the best choices in computer science). Let’s think about this: a linear operation means that as the number of items increases, the time that it takes to perform the operation tends to increase in a linear fashion.  Put crudely, this means if you double the collection size, you might expect the operation to take something like the order of twice as long.  Linear operations tend to be bad for performance because they mean that to perform some operation on a collection, you must potentially “visit” every item in the collection.  Consider finding an item in a List<T>: if you want to see if the list has an item, you must potentially check every item in the list before you find it or determine it’s not found. Now, we could of course sort our list and then perform a binary search on it, but sorting is typically a linear-logarithmic complexity – O(n * log n) - and could involve temporary storage.  So performing a sort after each add would probably add more time.  As an alternative, we could use a SortedList<TKey, TValue> which sorts the list on every Add(), but this has a similar level of complexity to move the items and also requires a key and value, and in our case the key is the value. This is why sets tend to be the best choice for this type of processing: they don’t rely on separate keys and values for ordering – so they save space – and they typically don’t care about ordering – so they tend to be extremely performant.  The .NET BCL (Base Class Library) has had the HashSet<T> since .NET 3.5, but at that time it did not implement the ISet<T> interface.  As of .NET 4.0, HashSet<T> implements ISet<T> and a new set, the SortedSet<T> was added that gives you a set with ordering. HashSet<T> – For Unordered Storage of Sets When used right, HashSet<T> is a beautiful collection, you can think of it as a simplified Dictionary<T,T>.  That is, a Dictionary where the TKey and TValue refer to the same object.  This is really an oversimplification, but logically it makes sense.  I’ve actually seen people code a Dictionary<T,T> where they store the same thing in the key and the value, and that’s just inefficient because of the extra storage to hold both the key and the value. As it’s name implies, the HashSet<T> uses a hashing algorithm to find the items in the set, which means it does take up some additional space, but it has lightning fast lookups!  Compare the times below between HashSet<T> and List<T>: Operation HashSet<T> List<T> Add() O(1) O(1) at end O(n) in middle Remove() O(1) O(n) Contains() O(1) O(n)   Now, these times are amortized and represent the typical case.  In the very worst case, the operations could be linear if they involve a resizing of the collection – but this is true for both the List and HashSet so that’s a less of an issue when comparing the two. The key thing to note is that in the general case, HashSet is constant time for adds, removes, and contains!  This means that no matter how large the collection is, it takes roughly the exact same amount of time to find an item or determine if it’s not in the collection.  Compare this to the List where almost any add or remove must rearrange potentially all the elements!  And to find an item in the list (if unsorted) you must search every item in the List. So as you can see, if you want to create an unordered collection and have very fast lookup and manipulation, the HashSet is a great collection. And since HashSet<T> implements ICollection<T> and IEnumerable<T>, it supports nearly all the same basic operations as the List<T> and can use the System.Linq extension methods as well. All we have to do to switch from a List<T> to a HashSet<T>  is change our declaration.  Since List and HashSet support many of the same members, chances are we won’t need to change much else. 1: public sealed class OrderProcessor 2: { 3: private readonly HashSet<string> _subscriptions = new HashSet<string>(); 4:  5: // ... 6:  7: public PlaceOrderResponse PlaceOrder(Order newOrder) 8: { 9: // do some validation, of course... 10: 11: // check to see if already subscribed, if not add a subscription 12: if (!_subscriptions.Contains(newOrder.Symbol)) 13: { 14: // add the symbol to the list 15: _subscriptions.Add(newOrder.Symbol); 16: 17: // do whatever magic is needed to start a subscription for the symbol 18: } 19: 20: // place the order logic! 21: } 22:  23: // ... 24: } 25: Notice, we didn’t change any code other than the declaration for _subscriptions to be a HashSet<T>.  Thus, we can pick up the performance improvements in this case with minimal code changes. SortedSet<T> – Ordered Storage of Sets Just like HashSet<T> is logically similar to Dictionary<T,T>, the SortedSet<T> is logically similar to the SortedDictionary<T,T>. The SortedSet can be used when you want to do set operations on a collection, but you want to maintain that collection in sorted order.  Now, this is not necessarily mathematically relevant, but if your collection needs do include order, this is the set to use. So the SortedSet seems to be implemented as a binary tree (possibly a red-black tree) internally.  Since binary trees are dynamic structures and non-contiguous (unlike List and SortedList) this means that inserts and deletes do not involve rearranging elements, or changing the linking of the nodes.  There is some overhead in keeping the nodes in order, but it is much smaller than a contiguous storage collection like a List<T>.  Let’s compare the three: Operation HashSet<T> SortedSet<T> List<T> Add() O(1) O(log n) O(1) at end O(n) in middle Remove() O(1) O(log n) O(n) Contains() O(1) O(log n) O(n)   The MSDN documentation seems to indicate that operations on SortedSet are O(1), but this seems to be inconsistent with its implementation and seems to be a documentation error.  There’s actually a separate MSDN document (here) on SortedSet that indicates that it is, in fact, logarithmic in complexity.  Let’s put it in layman’s terms: logarithmic means you can double the collection size and typically you only add a single extra “visit” to an item in the collection.  Take that in contrast to List<T>’s linear operation where if you double the size of the collection you double the “visits” to items in the collection.  This is very good performance!  It’s still not as performant as HashSet<T> where it always just visits one item (amortized), but for the addition of sorting this is a good thing. Consider the following table, now this is just illustrative data of the relative complexities, but it’s enough to get the point: Collection Size O(1) Visits O(log n) Visits O(n) Visits 1 1 1 1 10 1 4 10 100 1 7 100 1000 1 10 1000   Notice that the logarithmic – O(log n) – visit count goes up very slowly compare to the linear – O(n) – visit count.  This is because since the list is sorted, it can do one check in the middle of the list, determine which half of the collection the data is in, and discard the other half (binary search).  So, if you need your set to be sorted, you can use the SortedSet<T> just like the HashSet<T> and gain sorting for a small performance hit, but it’s still faster than a List<T>. Unique Set Operations Now, if you do want to perform more set-like operations, both implementations of ISet<T> support the following, which play back towards the mathematical set operations described before: IntersectWith() – Performs the set intersection of two sets.  Modifies the current set so that it only contains elements also in the second set. UnionWith() – Performs a set union of two sets.  Modifies the current set so it contains all elements present both in the current set and the second set. ExceptWith() – Performs a set difference of two sets.  Modifies the current set so that it removes all elements present in the second set. IsSupersetOf() – Checks if the current set is a superset of the second set. IsSubsetOf() – Checks if the current set is a subset of the second set. For more information on the set operations themselves, see the MSDN description of ISet<T> (here). What Sets Don’t Do Don’t get me wrong, sets are not silver bullets.  You don’t really want to use a set when you want separate key to value lookups, that’s what the IDictionary implementations are best for. Also sets don’t store temporal add-order.  That is, if you are adding items to the end of a list all the time, your list is ordered in terms of when items were added to it.  This is something the sets don’t do naturally (though you could use a SortedSet with an IComparer with a DateTime but that’s overkill) but List<T> can. Also, List<T> allows indexing which is a blazingly fast way to iterate through items in the collection.  Iterating over all the items in a List<T> is generally much, much faster than iterating over a set. Summary Sets are an excellent tool for maintaining a lookup table where the item is both the key and the value.  In addition, if you have need for the mathematical set operations, the C# sets support those as well.  The HashSet<T> is the set of choice if you want the fastest possible lookups but don’t care about order.  In contrast the SortedSet<T> will give you a sorted collection at a slight reduction in performance.   Technorati Tags: C#,.Net,Little Wonders,BlackRabbitCoder,ISet,HashSet,SortedSet

    Read the article

  • New TPerlRegEx Compatible with Delphi XE

    - by Jan Goyvaerts
    The new RegularExpressionsCore unit in Delphi XE is based on the PerlRegEx unit that I wrote many years ago. Since I donated full rights to a copy rather than full rights to the original, I can continue to make my version of TPerlRegEx available to people using older versions of Delphi. I did make a few changes to the code to modernize it a bit prior to donating a copy to Embarcadero. The latest TPerlRegEx includes those changes. This allows you to use the same regex-based code using the RegularExpressionsCore unit in Delphi XE, and the PerlRegEx unit in Delphi 2010 and earlier. If you’re writing new code using regular expressions in Delphi 2010 or earlier, I strongly recomment you use the new version of my PerlRegEx unit. If you later migrate your code to Delphi XE, all you have to do is replace PerlRegEx with RegularExrpessionsCore in the uses clause of your units. If you have code written using an older version of TPerlRegEx that you want to migrate to the latest TPerlRegEx, you’ll need to take a few changes into account. The original TPerlRegEx was developed when Borland’s goal was to have a component for everything on the component palette. So the old TPerlRegEx derives from TComponent, allowing you to put it on the component palette and drop it on a form. The new TPerlRegEx derives from TObject. It can only be instantiated at runtime. If you want to migrate from an older version of TPerlRegEx to the latest TPerlRegEx, start with removing any TPerlRegEx components you may have placed on forms or data modules and instantiate the objects at runtime instead. When instantiating at runtime, you no longer need to pass an owner component to the Create() constructor. Simply remove the parameter. Some of the property and method names in the original TPerlRegEx were a bit unwieldy. These have been renamed in the latest TPerlRegEx. Essentially, in all identifiers SubExpression was replaced with Group and MatchedExpression was replaced with Matched. Here is a complete list of the changed identifiers: Old Identifier New Identifier StoreSubExpression StoreGroups NamedSubExpression NamedGroup MatchedExpression MatchedText MatchedExpressionLength MatchedLength MatchedExpressionOffset MatchedOffset SubExpressionCount GroupCount SubExpressions Groups SubExpressionLengths GroupLengths SubExpressionOffsets GroupOffsets Download TPerlRegEx. Source is included under the MPL 1.1 license.

    Read the article

  • C#/.NET Little Wonders: The Joy of Anonymous Types

    - 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. In the .NET 3 Framework, Microsoft introduced the concept of anonymous types, which provide a way to create a quick, compiler-generated types at the point of instantiation.  These may seem trivial, but are very handy for concisely creating lightweight, strongly-typed objects containing only read-only properties that can be used within a given scope. Creating an Anonymous Type In short, an anonymous type is a reference type that derives directly from object and is defined by its set of properties base on their names, number, types, and order given at initialization.  In addition to just holding these properties, it is also given appropriate overridden implementations for Equals() and GetHashCode() that take into account all of the properties to correctly perform property comparisons and hashing.  Also overridden is an implementation of ToString() which makes it easy to display the contents of an anonymous type instance in a fairly concise manner. To construct an anonymous type instance, you use basically the same initialization syntax as with a regular type.  So, for example, if we wanted to create an anonymous type to represent a particular point, we could do this: 1: var point = new { X = 13, Y = 7 }; Note the similarity between anonymous type initialization and regular initialization.  The main difference is that the compiler generates the type name and the properties (as readonly) based on the names and order provided, and inferring their types from the expressions they are assigned to. It is key to remember that all of those factors (number, names, types, order of properties) determine the anonymous type.  This is important, because while these two instances share the same anonymous type: 1: // same names, types, and order 2: var point1 = new { X = 13, Y = 7 }; 3: var point2 = new { X = 5, Y = 0 }; These similar ones do not: 1: var point3 = new { Y = 3, X = 5 }; // different order 2: var point4 = new { X = 3, Y = 5.0 }; // different type for Y 3: var point5 = new {MyX = 3, MyY = 5 }; // different names 4: var point6 = new { X = 1, Y = 2, Z = 3 }; // different count Limitations on Property Initialization Expressions The expression for a property in an anonymous type initialization cannot be null (though it can evaluate to null) or an anonymous function.  For example, the following are illegal: 1: // Null can't be used directly. Null reference of what type? 2: var cantUseNull = new { Value = null }; 3:  4: // Anonymous methods cannot be used. 5: var cantUseAnonymousFxn = new { Value = () => Console.WriteLine(“Can’t.”) }; Note that the restriction on null is just that you can’t use it directly as the expression, because otherwise how would it be able to determine the type?  You can, however, use it indirectly assigning a null expression such as a typed variable with the value null, or by casting null to a specific type: 1: string str = null; 2: var fineIndirectly = new { Value = str }; 3: var fineCast = new { Value = (string)null }; All of the examples above name the properties explicitly, but you can also implicitly name properties if they are being set from a property, field, or variable.  In these cases, when a field, property, or variable is used alone, and you don’t specify a property name assigned to it, the new property will have the same name.  For example: 1: int variable = 42; 2:  3: // creates two properties named varriable and Now 4: var implicitProperties = new { variable, DateTime.Now }; Is the same type as: 1: var explicitProperties = new { variable = variable, Now = DateTime.Now }; But this only works if you are using an existing field, variable, or property directly as the expression.  If you use a more complex expression then the name cannot be inferred: 1: // can't infer the name variable from variable * 2, must name explicitly 2: var wontWork = new { variable * 2, DateTime.Now }; In the example above, since we typed variable * 2, it is no longer just a variable and thus we would have to assign the property a name explicitly. ToString() on Anonymous Types One of the more trivial overrides that an anonymous type provides you is a ToString() method that prints the value of the anonymous type instance in much the same format as it was initialized (except actual values instead of expressions as appropriate of course). For example, if you had: 1: var point = new { X = 13, Y = 42 }; And then print it out: 1: Console.WriteLine(point.ToString()); You will get: 1: { X = 13, Y = 42 } While this isn’t necessarily the most stunning feature of anonymous types, it can be handy for debugging or logging values in a fairly easy to read format. Comparing Anonymous Type Instances Because anonymous types automatically create appropriate overrides of Equals() and GetHashCode() based on the underlying properties, we can reliably compare two instances or get hash codes.  For example, if we had the following 3 points: 1: var point1 = new { X = 1, Y = 2 }; 2: var point2 = new { X = 1, Y = 2 }; 3: var point3 = new { Y = 2, X = 1 }; If we compare point1 and point2 we’ll see that Equals() returns true because they overridden version of Equals() sees that the types are the same (same number, names, types, and order of properties) and that the values are the same.   In addition, because all equal objects should have the same hash code, we’ll see that the hash codes evaluate to the same as well: 1: // true, same type, same values 2: Console.WriteLine(point1.Equals(point2)); 3:  4: // true, equal anonymous type instances always have same hash code 5: Console.WriteLine(point1.GetHashCode() == point2.GetHashCode()); However, if we compare point2 and point3 we get false.  Even though the names, types, and values of the properties are the same, the order is not, thus they are two different types and cannot be compared (and thus return false).  And, since they are not equal objects (even though they have the same value) there is a good chance their hash codes are different as well (though not guaranteed): 1: // false, different types 2: Console.WriteLine(point2.Equals(point3)); 3:  4: // quite possibly false (was false on my machine) 5: Console.WriteLine(point2.GetHashCode() == point3.GetHashCode()); Using Anonymous Types Now that we’ve created instances of anonymous types, let’s actually use them.  The property names (whether implicit or explicit) are used to access the individual properties of the anonymous type.  The main thing, once again, to keep in mind is that the properties are readonly, so you cannot assign the properties a new value (note: this does not mean that instances referred to by a property are immutable – for more information check out C#/.NET Fundamentals: Returning Data Immutably in a Mutable World). Thus, if we have the following anonymous type instance: 1: var point = new { X = 13, Y = 42 }; We can get the properties as you’d expect: 1: Console.WriteLine(“The point is: ({0},{1})”, point.X, point.Y); But we cannot alter the property values: 1: // compiler error, properties are readonly 2: point.X = 99; Further, since the anonymous type name is only known by the compiler, there is no easy way to pass anonymous type instances outside of a given scope.  The only real choices are to pass them as object or dynamic.  But really that is not the intention of using anonymous types.  If you find yourself needing to pass an anonymous type outside of a given scope, you should really consider making a POCO (Plain Old CLR Type – i.e. a class that contains just properties to hold data with little/no business logic) instead. Given that, why use them at all?  Couldn’t you always just create a POCO to represent every anonymous type you needed?  Sure you could, but then you might litter your solution with many small POCO classes that have very localized uses. It turns out this is the key to when to use anonymous types to your advantage: when you just need a lightweight type in a local context to store intermediate results, consider an anonymous type – but when that result is more long-lived and used outside of the current scope, consider a POCO instead. So what do we mean by intermediate results in a local context?  Well, a classic example would be filtering down results from a LINQ expression.  For example, let’s say we had a List<Transaction>, where Transaction is defined something like: 1: public class Transaction 2: { 3: public string UserId { get; set; } 4: public DateTime At { get; set; } 5: public decimal Amount { get; set; } 6: // … 7: } And let’s say we had this data in our List<Transaction>: 1: var transactions = new List<Transaction> 2: { 3: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = 2200.00m }, 4: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = -1100.00m }, 5: new Transaction { UserId = "Jim", At = DateTime.Now.AddDays(-1), Amount = 900.00m }, 6: new Transaction { UserId = "John", At = DateTime.Now.AddDays(-2), Amount = 300.00m }, 7: new Transaction { UserId = "John", At = DateTime.Now, Amount = -10.00m }, 8: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = 200.00m }, 9: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = -50.00m }, 10: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = -100.00m }, 11: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = 300.00m }, 12: }; So let’s say we wanted to get the transactions for each day for each user.  That is, for each day we’d want to see the transactions each user performed.  We could do this very simply with a nice LINQ expression, without the need of creating any POCOs: 1: // group the transactions based on an anonymous type with properties UserId and Date: 2: byUserAndDay = transactions 3: .GroupBy(tx => new { tx.UserId, tx.At.Date }) 4: .OrderBy(grp => grp.Key.Date) 5: .ThenBy(grp => grp.Key.UserId); Now, those of you who have attempted to use custom classes as a grouping type before (such as GroupBy(), Distinct(), etc.) may have discovered the hard way that LINQ gets a lot of its speed by utilizing not on Equals(), but also GetHashCode() on the type you are grouping by.  Thus, when you use custom types for these purposes, you generally end up having to write custom Equals() and GetHashCode() implementations or you won’t get the results you were expecting (the default implementations of Equals() and GetHashCode() are reference equality and reference identity based respectively). As we said before, it turns out that anonymous types already do these critical overrides for you.  This makes them even more convenient to use!  Instead of creating a small POCO to handle this grouping, and then having to implement a custom Equals() and GetHashCode() every time, we can just take advantage of the fact that anonymous types automatically override these methods with appropriate implementations that take into account the values of all of the properties. Now, we can look at our results: 1: foreach (var group in byUserAndDay) 2: { 3: // the group’s Key is an instance of our anonymous type 4: Console.WriteLine("{0} on {1:MM/dd/yyyy} did:", group.Key.UserId, group.Key.Date); 5:  6: // each grouping contains a sequence of the items. 7: foreach (var tx in group) 8: { 9: Console.WriteLine("\t{0}", tx.Amount); 10: } 11: } And see: 1: Jaime on 06/18/2012 did: 2: -100.00 3: 300.00 4:  5: John on 06/19/2012 did: 6: 300.00 7:  8: Jim on 06/20/2012 did: 9: 900.00 10:  11: Jane on 06/21/2012 did: 12: 200.00 13: -50.00 14:  15: Jim on 06/21/2012 did: 16: 2200.00 17: -1100.00 18:  19: John on 06/21/2012 did: 20: -10.00 Again, sure we could have just built a POCO to do this, given it an appropriate Equals() and GetHashCode() method, but that would have bloated our code with so many extra lines and been more difficult to maintain if the properties change.  Summary Anonymous types are one of those Little Wonders of the .NET language that are perfect at exactly that time when you need a temporary type to hold a set of properties together for an intermediate result.  While they are not very useful beyond the scope in which they are defined, they are excellent in LINQ expressions as a way to create and us intermediary values for further expressions and analysis. Anonymous types are defined by the compiler based on the number, type, names, and order of properties created, and they automatically implement appropriate Equals() and GetHashCode() overrides (as well as ToString()) which makes them ideal for LINQ expressions where you need to create a set of properties to group, evaluate, etc. Technorati Tags: C#,CSharp,.NET,Little Wonders,Anonymous Types,LINQ

    Read the article

  • RIA Services Filter descriptor

    - by Mohit
    I have a Filterdescriptor as shown below. The propertypath is of type 'char?' I get following InvalidOperationException when I filter by entering a value Y InnerException {System.InvalidOperationException: A FilterDescriptor with its PropertyPath equal to 'Valid' cannot be evaluated. --- System.ArgumentException: Operator 'StartsWith' incompatible with operand types 'Char?' and 'Char?' --- System.ArgumentNullException: Value cannot be null. Parameter name: method at System.Linq.Expressions.Expression.ValidateCallArgs(Expression instance, MethodInfo method, ReadOnlyCollection1& arguments) at System.Linq.Expressions.Expression.Call(Expression instance, MethodInfo method, IEnumerable1 arguments) at System.Linq.Expressions.Expression.Call(Expression instance, MethodInfo method, Expression[] arguments) at System.Windows.Controls.LinqHelper.GenerateMethodCall(String methodName, Expression left, Expression right) at System.Windows.Controls.LinqHelper.GenerateStartsWith(Expression left, Expression right) at System.Windows.Controls.LinqHelper.BuildFilterExpression(Expression propertyExpression, FilterOperator filterOperator, Expression valueExpression, Boolean isCaseSensitive, Expression& filterExpression) --- End of inner exception stack trace --- --- End of inner exception stack trace ---} System.Exception {System.InvalidOperationException}

    Read the article

  • Left Join in Subsonic 3

    - by user303187
    I'm trying to do a left join in subsonic 3 using linq but it doesn't seem to work, I get a big error. var post = from p in Post.All() join q in Quote.All() on p.ID equals q.PostID into pq where p.ID == id.Value from qt in pq.DefaultIfEmpty() select new {p, qt}; I'm using subsonic 3, latest GIT version from Rob, but I'm getting an error, see below, when I try a left join. I have searched but I didn't found any solution. Can anyone explain to me why the error and how to fix it? Thanks Expression of type 'System.Collections.Generic.IEnumerable1[GetAQuote.Post]' cannot be used for parameter of type 'System.Linq.IQueryable1[GetAQuote.Post]' of method 'System.Linq.IQueryable1[<>f__AnonymousType221[GetAQuote.Post], System.Collections.Generic.IEnumerable1%5BGetAQuote.Quote%5D, System.Linq.Expressions.Expression1[System.Func2%5BGetAQuote.Post,System.Int32%5D%5D, System.Linq.Expressions.Expression1[System.Func2%5BGetAQuote.Quote,System.Int32%5D%5D, System.Linq.Expressions.Expression1[System.Func3%5BGetAQuote.Post,System.Collections.Generic.IEnumerable1[GetAQuote.Quote],<>f__AnonymousType22%5BGetAQuote.Post,System.Collections.Generic.IEnumerable1%5BGetAQuote.Quote%5D%5D%5D%5D"GetAQuote.Post,System.Collections.Generic.IEnumerable1[GetAQuote.Quote]]] GroupJoin[Post,Quote,Int32,<f__AnonymousType22'`

    Read the article

  • translate by replacing words inside existing text

    - by Berry Tsakala
    What are common approaches for translating certain words (or expressions) inside a given text, when the text must be reconstructed (with punctuations and everythin.) ? The translation comes from a lookup table, and covers words, collocations, and emoticons like L33t, CUL8R, :-), etc. Simple string search-and-replace is not enough since it can replace part of longer words (cat dog ? caterpillar dogerpillar). Assume the following input: s = "dogbert, started a dilbert dilbertion proces cat-bert :-)" after translation, i should receive something like: result = "anna, started a george dilbertion process cat-bert smiley" I can't simply tokenize, since i loose punctuations and word positions. Regular expressions, works for normal words, but don't catch special expressions like the smiley :-) but it does . re.sub(r'\bword\b','translation',s) ==> translation re.sub(r'\b:-\)\b','smiley',s) ==> :-) for now i'm using the above mentioned regex, and simple replace for the non-alphanumeric words, but it's far from being bulletproof. (p.s. i'm using python)

    Read the article

  • How can I build a Truth Table Generator?

    - by KingNestor
    I'm looking to write a Truth Table Generator as a personal project. There are several web-based online ones here and here. (Example screenshot of an existing Truth Table Generator) I have the following questions: How should I go about parsing expressions like: ((P = Q) & (Q = R)) = (P = R) Should I use a parser generator like ANTLr or YACC, or use straight regular expressions? Once I have the expression parsed, how should I go about generating the truth table? Each section of the expression needs to be divided up into its smallest components and re-built from the left side of the table to the right. How would I evaluate something like that? Can anyone provide me with tips concerning the parsing of these arbitrary expressions and eventually evaluating the parsed expression?

    Read the article

  • Why does this regular expression fail?

    - by Stephen
    I have a password validation script in PHP that checks a few different regular expressions, and throws a unique error message depending on which one fails. Here is an array of the regular expressions and the error messages that are thrown if the match fails: array( 'rule1' => array( '/^.*[\d].*$/i', 'Password must contain at least one number.' ), 'rule2' => array( '/^.*[a-z].*$/i', 'Password must contain at least one lowercase letter' ), 'rule3' => array( '/^.*[A-Z].*$/i', 'Password must contain at least one uppercase letter' ), 'rule4' => array( '/^.*[~!@#$%^&*()_+=].*$/i', 'Password must contain at least one special character [~!@#$%^&*()_+=]' ) ); For some reason, no matter what I pass through the validation, the "Special Characters" rule fails. I'm guessing it's a problem with the expression. If there's a better (or correct) way to write these expressions, I'm all ears!

    Read the article

  • How to check that a regular expression fall into infty loop or not?

    - by Sorush Rabiee
    I'm trying to learn and hopefully use regular expression with Qt. I found that some patterns cause handler to fall into loop. for example searching \b\b in a text, never will terminate. and number of these expressions is infinite (\b\b\b,\b\b\b\b and so on). I'd like to determine and control all invalid expressions. Is there an algorithm to distinguish valid and invalid expressions? If not, how can I prevent my program from falling into an infinite loop?

    Read the article

  • Symbolic Regular Expression Exploration

    - by Robz / Fervent Coder
    This is a pretty sweet little tool. Rex (Regular Expression Exploration) is a tool that allows you to give it a regular expression and it returns matching strings. The example below creates10 strings that start and end with a number and have at least 2 characters: > rex.exe "^\d.*\d$" /k:10 This is something I could use to validate/generate the Regular Expressions I have created with both UppercuT and RoundhousE. Check out the video below: Margus Veanes - Rex - Symbolic Regular Expression Exploration Margus Veanes, a Researcher from the RiSE group at Microsoft Research, gives an overview of Rex, a tool that generates matching string from .NET regular expressions. Rex turns regular expres...

    Read the article

  • ODI 11g - Cleaning control characters and User Functions

    - by David Allan
    In ODI user functions have a poor name really, they should be user expressions - a way of wrapping common expressions that you may wish to reuse many times - across many different technologies is an added bonus. To illustrate look at the problem of how to remove control characters from text. Users ask these types of questions over all technologies - Microsoft SQL Server, Oracle, DB2 and for many years - how do I clean a string, how do I tokenize a string and so on. After some searching around you will find a few ways of doing this, in Oracle there is a convenient way of using the TRANSLATE and REPLACE functions. So you can convert some text using the following SQL; replace( translate('This is my string'||chr(9)||' which has a control character', chr(3)||chr(4)||chr(5)||chr(9), chr(3) ), chr(3), '' ) If you had many columns to perform this kind of transformation on, in the Oracle database the natural solution you'd go to would be to code this as a PLSQL function since you don't want the code splattered everywhere. Someone tells you that there is another control character that needs added equals a maintenance headache. Coding it as a PLSQL function will incur a context switch between SQL and PLSQL which could prove costly. In ODI user functions let you capture this expression text and reference it many times across your mappings. This will protect the expression from being copy-pasted by developers and make maintenance much simpler - change the expression definition in one place. Firstly define a name and a syntax for the user function, I am calling it UF_STRIP_BAD_CHARACTERS and it has one parameter an input string;  We then can define an implementation for each technology we will use it, I will define Oracle's using the inputString parameter and the TRANSLATE and REPLACE functions with whatever control characters I want to replace; I can then use this inside mapping expressions in ODI, below I am cleaning the ENAME column - a fabricated example but you get the gist.  Note when I use the user function the function name remains in the text of the mapping, the actual expression is not substituted until I generate the scenario. If you generate the scenario and export the scenario you can have a peak at the code that is processed in the runtime - below you can see a snippet of my export scenario;  That's all for now, hopefully a useful snippet of info.

    Read the article

  • Regular Expression Transformation

    The regular expression transformation exposes the power of regular expression matching within the pipeline. One or more columns can be selected, and for each column an individual expression can be applied. The way multiple columns are handled can be set on the options page. The AND option means all columns must match, whilst the OR option means only one column has to match. If rows pass their tests then rows are passed down the successful match output. Rows that fail are directed down the alternate output. This transformation is ideal for validating data through the use of regular expressions. You can enter any expression you like, or select a pre-configured expression within the editor. You can expand the list of pre-configured expressions yourself. These are stored in a Xml file, %ProgramFiles%\Microsoft SQL Server\nnn\DTS\PipelineComponents\RegExTransform.xml, where nnn represents the folder version, 90 for 2005, 100 for 2008 and 110 for 2012. If you want to use regular expressions to manipulate data, rather than just validating it, try the RegexClean Transformation. The component is provided as an MSI file, however for 2005/200 you will have to add the transformation to the Visual Studio toolbox by hand. This process has been described in detail in the related FAQ entry for How do I install a task or transform component?, just select Regular Expression Transformation in the Choose Toolbox Items window. Downloads The Regular Expression Transformation is available for SQL Server 2005, SQL Server 2008 (includes R2) and SQL Server 2012. Please choose the version to match your SQL Server version, or you can install multiple versions and use them side by side if you have more than one version of SQL Server installed. Regular Expression Transformation for SQL Server 2005 Regular Expression Transformation for SQL Server 2008 Regular Expression Transformation for SQL Server 2012 Version History SQL Server 2012Version 2.0.0.87 - SQL Server 2012 release. Includes upgrade support for both 2005 and 2008 packages to 2012. (5 Jun 2012) SQL Server 2008Version 2.0.0.87 - Release for SQL Server 2008 Integration Services. (10 Oct 2008) SQL Server 2005 Version 1.1.0.93 - Added option for you to choose AND or OR logic when multiple columns have been selected. Previously behaviour was OR only. (31 Jul 2008) Version 1.0.0.76 - Installer update and improved exception handling. (28 Jan 2008) Version 1.0.0.41 - Update for user interface stability fixes. (2 Aug 2006) Version 1.0.0.24 - SQL Server 2005 RTM Refresh. SP1 Compatibility Testing. (12 Jun 2006) Version 1.0.0.9 - Public Release for SQL Server 2005 IDW 15 June CTP (29 Aug 2005) Screenshots  

    Read the article

  • [News] Utiliser le framework de bouchon Moq

    Moq est un framework permettant de mettre en oeuvre les mock-objets destin?es aux phases de tests. Cet excellent article illustre le principe : " (...) it is intended to be straightforward and easy to use mocking framework that doesn?t require any prior knowledge of the mocking concepts. So, it doesn't requires deep learning curve from the developers. It takes full advantage of the .NET 3.5 expression trees and the lambda expressions. Any of the methods and properties of the mock object can be easily represented in the lambda expressions."

    Read the article

  • Speaking at Houston Techfest on September 8

    - by John Paul Cook
    I’m giving my talk on SQL Server and SSMS Tips and Tricks at Houston Techfest on September 8, 2012. It will be similar to the one I gave at last year’s Techfest and also the one I gave at the Houston SQL Server User Group meeting last month. It will be mostly different from the one I gave at the last SQL Saturday in Houston. I will cover regular expressions. If you bring your laptop with you, you can follow along with me to make sure you leave able to actually use regular expressions. If you are...(read more)

    Read the article

  • ClearTrace Supports SQL Server 2008 R2

    - by Bill Graziano
    It was a long time coming and I hope worth the wait.  If you have SQL Server 2008 R2 installed on the same box as ClearTrace and you download the latest ClearTrace build (36) you’ll be able to read SQL Server 2008 R2 traces.  I also fixed a bug handling very, very large SQL statements.  I encountered an INSERT statement that was 12MB in size.  It was storing XML in a database.  ClearTrace uses regular expressions to clean up the SQL it finds.  Running two dozen regular expressions over this 12MB string caused the application to crash.  In this build I’m just skipping any statement over 1MB.  I’ll do something a little nicer in the next build. (And if you don’t want to download ClearTrace you can test the online version at www.TraceTune.com)

    Read the article

  • 3 SQL Join Concepts to Help You Choose the Right Join

    What do SQL joins and the "teach a man to fish" Chinese proverb have in common? SQL joins, like regular expressions, are one of those commonplace programming tasks in which true success is entirely dependent upon your ability to conceptualize the outcome. Fail to do so and you'll likely wind up spending a few hours in a frustrating round of trial and error. Like regular expressions, the proliferation of online examples has actually contributed to the frustration, providing the equivalent of a day's worth of fish rather than the proverbial fishing pool. The Future of SQL Server MonitoringMonitor wherever, whenever with Red Gate's SQL Monitor. See it live in action now.

    Read the article

  • Equations saved from Word 2007 for Windows do not appear in Word 2008 for Mac

    - by user36081
    I am a math teacher who uses Word 2008 on the Mac, and I need to collaborate with other teachers who are using Word 2007 under Windows. When they send me a document with mathematical equations in it, I can open it but not see the equations or the document loses formatting such as superscript for exponents. On this page of Known Issues in Word 2008, Microsoft says, Equations saved from Word 2007 for Windows do not appear in Word 2008 for Mac Equations saved in Word 2007 for Windows are not supported in Word 2008 for Mac. The equations will be preserved so that they display correctly in Word 2007, but will appear as placeholders in Word 2008. What can I do to collaborate with users of Word 2007 on mathematical documents?

    Read the article

  • Uget tray icon not showing

    - by ArK
    Since I upgraded to Saucy, Uget is not showing in the system tray, although the Always show tray icon option in Uget settings is checked. P.S. this happens only with Uget, all the other Softwares have working tray icons (vlc,qbittorrent..) Here is the snapshot which shows the settings of Uget: sudo dpkg -l | grep -e "^rc" -e "^iU": rc account-plugin-generic-oauth 0.10bzr13.03.26-0ubuntu1.1 i386 GNOME Control Center account plugin for single signon - generic OAuth rc appmenu-gtk:i386 12.10.3daily13.04.03-0ubuntu1 i386 Export GTK menus over DBus rc appmenu-gtk3:i386 12.10.3daily13.04.03-0ubuntu1 i386 Export GTK menus over DBus rc arora 0.11.0-0ubuntu1 i386 simple cross platform web browser rc buc 0.5.2-20 i386 BUC rc clementine 1.1.1+dfsg-2ubuntu1 i386 modern music player and library organizer rc epiphany-browser 3.6.1-2ubuntu1 i386 Intuitive GNOME web browser rc epiphany-browser-data 3.6.1-2ubuntu3 all Data files for the GNOME web browser rc fancontrol 1:3.3.3-1ubuntu1 all utilities to read temperature/voltage/fan sensors rc flaremonitor 1.0-5 i386 It is an advanced browser integration helper module of FlareGet rc google-chrome-stable 28.0.1500.95-r213514 i386 The web browser from Google rc hal 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer rc hotot-gtk 1:0.9.8.5+git20120630.884797d-1 all lightweight microblogging client - GTK+ wrapper rc jockey-common 0.9.7-0ubuntu13 all user interface and desktop integration for driver management rc libanalitza4abi1 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions rc libanalitza5 4:4.11.2-0ubuntu1 i386 library to work with mathematical expressions rc libanalitzagui4abi2 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions - GUI routines rc libanalitzaplot4 4:4.10.4-0ubuntu0.1 i386 library to work with mathematical expressions - plot routines rc libavcodec53:i386 6:0.8.6-1ubuntu2 i386 Libav codec library rc libavutil51:i386 6:0.8.6-1ubuntu2 i386 Libav utility library rc libbamf3-1:i386 0.4.0daily13.06.19~13.04-0ubuntu1 i386 Window matching library - shared library rc libboost-iostreams1.49.0 1.49.0-4 i386 Boost.Iostreams Library rc libboost-program-options1.49.0 1.49.0-4 i386 program options library for C++ rc libboost-python1.49.0 1.49.0-4 i386 Boost.Python Library rc libboost-thread1.49.0 1.49.0-4 i386 portable C++ multi-threading rc libbrlapi0.5:i386 4.4-8ubuntu4 i386 braille display access via BRLTTY - shared library rc libcamel-1.2-40 3.6.4-0ubuntu1.1 i386 Evolution MIME message handling library rc libcolumbus0-0 0.4.0daily13.04.16~13.04-0ubuntu1 i386 error tolerant matching engine - shared library rc libdns95 1:9.9.2.dfsg.P1-2ubuntu2.1 i386 DNS Shared Library used by BIND rc libdvbpsi7 0.2.2-1 i386 library for MPEG TS and DVB PSI tables decoding and generating rc libebackend-1.2-5 3.6.4-0ubuntu1.1 i386 Utility library for evolution data servers rc libechonest2.0:i386 2.0.2-0ubuntu1 i386 Qt library for communicating with The Echo Nest platform rc libechonest2.1:i386 2.1.0-2 i386 Qt library for communicating with The Echo Nest platform rc libedata-book-1.2-15 3.6.4-0ubuntu1.1 i386 Backend library for evolution address books rc libedata-cal-1.2-18 3.6.4-0ubuntu1.1 i386 Backend library for evolution calendars rc libftgl2 2.1.3~rc5-4ubuntu1 i386 library to render text in OpenGL using FreeType rc libgc1c3:i386 1:7.2d-0ubuntu5 i386 conservative garbage collector for C and C++ rc libgnome-desktop-3-4 3.6.3-0ubuntu1 i386 Utility library for loading .desktop files - runtime files rc libgtksourceview-3.0-0:i386 3.6.3-0ubuntu1 i386 shared libraries for the GTK+ syntax highlighting widget rc libgweather-3-1 3.6.2-0ubuntu1 i386 GWeather shared library rc libhal-storage1 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer - shared library for storage devices rc libhal1 0.5.14-8ubuntu1 i386 Hardware Abstraction Layer - shared library rc libharfbuzz0:i386 0.9.13-1 i386 OpenType text shaping engine rc libhd16 16.0-2.2 i386 Hardware identification system library rc libibus-1.0-0:i386 1.4.2-0ubuntu2 i386 Intelligent Input Bus - shared library rc libical0 0.48-2 i386 iCalendar library implementation in C (runtime) rc libimobiledevice3 1.1.4-1ubuntu6.2 i386 Library for communicating with the iPhone and iPod Touch rc libisc92 1:9.9.2.dfsg.P1-2ubuntu2.1 i386 ISC Shared Library used by BIND rc libkdegamesprivate1 4:4.10.2-0ubuntu1 i386 private shared library for KDE games rc libkeybinder0 0.3.0-1ubuntu1 i386 registers global key bindings for applications rc libkgapi0:i386 0.4.4-0ubuntu1 i386 Google API library for KDE rc liblastfm1:i386 1.0.7-2 i386 Last.fm web services library rc libnetfilter-queue1 1.0.2-1 i386 Netfilter netlink-queue library rc libnl1:i386 1.1-7ubuntu1 i386 library for dealing with netlink sockets rc libossp-uuid16 1.6.2-1.3 i386 OSSP uuid ISO-C and C++ - shared library rc libpackagekit-glib2-14:i386 0.7.6-3ubuntu1 i386 Library for accessing PackageKit using GLib rc libpoppler28:i386 0.20.5-1ubuntu3 i386 PDF rendering library rc libprojectm2 2.1.0+dfsg-1build1 i386 Advanced Milkdrop-compatible music visualization library rc libqxt-core0:i386 0.6.1-7 i386 extensions to Qt core classes (LibQxt) rc libqxt-gui0:i386 0.6.1-7 i386 extensions to Qt GUI classes (LibQxt) rc libraw5:i386 0.14.7-0ubuntu1.13.04.2 i386 raw image decoder library rc librhythmbox-core6 2.98-0ubuntu5 i386 support library for the rhythmbox music player rc librhythmbox-core7 3.0.1-0~13.10~ppa1 i386 support library for the rhythmbox music player rc libsnmp15 5.4.3~dfsg-2.7ubuntu1 i386 SNMP (Simple Network Management Protocol) library rc libsqlite0 2.8.17-8fakesync1 i386 SQLite shared library rc libsyncdaemon-1.0-1 4.2.0-0ubuntu1 i386 Ubuntu One synchronization daemon library rc libtiff4:i386 3.9.7-2ubuntu1 i386 Tag Image File Format (TIFF) library (old version) rc libunity-core-6.0-5 7.0.0daily13.06.19~13.04-0ubuntu1 i386 Core library for the Unity interface. rc libva-wayland1:i386 1.2.1-0ubuntu0~raring i386 Video Acceleration (VA) API for Linux -- Wayland runtime rc libwayland0:i386 1.0.5-0ubuntu1 i386 wayland compositor infrastructure - shared libraries rc libwebp2:i386 0.1.3-3 i386 Lossy compression of digital photographic images. rc linux-image-3.8.0-19-generic 3.8.0-19.30 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-21-generic 3.8.0-21.32 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-22-generic 3.8.0-22.33 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-26-generic 3.8.0-26.38 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.8.0-27-generic 3.8.0-27.40 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-3.9.0-030900-generic 3.9.0-030900.201304291257 i386 Linux kernel image for version 3.9.0 on 32 bit x86 SMP rc linux-image-3.9.0-030900rc8-generic 3.9.0-030900rc8.201304211835 i386 Linux kernel image for version 3.9.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-19-generic 3.8.0-19.30 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-21-generic 3.8.0-21.32 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-22-generic 3.8.0-22.33 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-26-generic 3.8.0-26.38 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc linux-image-extra-3.8.0-27-generic 3.8.0-27.40 i386 Linux kernel image for version 3.8.0 on 32 bit x86 SMP rc preload 0.6.4-2 i386 adaptive readahead daemon rc steam-launcher 1.0.0.39 all Launcher for the Steam software distribution service rc super-boot-manager 0.7.15 all Simple gui to configure Grub2, Burg and Plymouth. rc totem 3.6.3-0ubuntu6 i386 Simple media player for the GNOME desktop based on GStreamer rc transmission-gtk 2.77-0ubuntu1 i386 lightweight BitTorrent client (GTK interface) rc unity-common 7.0.0daily13.06.19~13.04-0ubuntu1 all Common files for the Unity interface. rc vino 3.6.2-0ubuntu4 i386 VNC server for GNOME rc wicd-daemon 1.7.2.4-4.1 all wired and wireless network manager - daemon rc wicd-gtk 1.7.2.4-4.1 all wired and wireless network manager - GTK+ client rc xscreensaver 5.15-2ubuntu1 i386 Automatic screensaver for X rc xscreensaver-data 5.15-3ubuntu1 i386 data files to be shared among screensaver frontends sudo dpkg -l | grep uget: ii uget 1.10.3-1 i386 easy-to-use download manager written in GTK+ sudo dpkg -l | grep indicator: ii gir1.2-appindicator3-0.1 12.10.1+13.10.20130920-0ubuntu2 i386 Typelib files for libappindicator3-1. ii gir1.2-syncmenu-0.1 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status - bindings ii indicator-applet-complete 12.10.2+13.10.20130924.2-0ubuntu1 i386 Clone of the GNOME panel indicator applet ii indicator-application 12.10.1daily13.01.25-0ubuntu1 i386 Application Indicators ii indicator-appmenu 13.01.0+13.10.20130930-0ubuntu1 i386 Indicator for application menus. ii indicator-bluetooth 0.0.6+13.10.20131016-0ubuntu1 i386 System bluetooth indicator. ii indicator-datetime 13.10.0+13.10.20131023.2-0ubuntu1 i386 Simple clock ii indicator-keyboard 0.0.0+13.10.20131010.1-0ubuntu1 i386 Keyboard indicator ii indicator-messages 13.10.1+13.10.20131011-0ubuntu1 i386 indicator that collects messages that need a response ii indicator-multiload 0.3-0ubuntu1 i386 Graphical system load indicator for CPU, ram, etc. ii indicator-power 12.10.6+13.10.20131008-0ubuntu1 i386 Indicator showing power state. ii indicator-printers 0.1.7daily13.03.01-0ubuntu1 i386 indicator showing active print jobs ii indicator-session 12.10.5+13.10.20131023.1-0ubuntu1 i386 indicator showing session management, status and user switching ii indicator-sound 12.10.2+13.10.20131011-0ubuntu1 i386 System sound indicator. ii indicator-sync 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status ii libappindicator1 12.10.1+13.10.20130920-0ubuntu2 i386 Application Indicators ii libappindicator3-1 12.10.1+13.10.20130920-0ubuntu2 i386 Application Indicators ii libindicator3-7 12.10.2+13.10.20130913-0ubuntu2 i386 panel indicator applet - shared library ii libindicator7 12.10.2+13.10.20130913-0ubuntu2 i386 panel indicator applet - shared library ii libsync-menu1:i386 12.10.5+13.10.20131011-0ubuntu1 i386 indicator for synchronisation processes status - libraries ii python-appindicator 12.10.1+13.10.20130920-0ubuntu2 i386 Python bindings for libappindicator ii sni-qt:i386 0.2.6-0ubuntu1 i386 indicator support for Qt ii telepathy-indicator 0.3.1daily13.06.19-0ubuntu1 i386 Desktop service to integrate Telepathy with the messaging menu.

    Read the article

  • from Java to SAS

    - by Giovanni Rossi
    I am a seasoned python,java,...other programmer having a (fairly advanced) mathematical education (so I do understand statistics and data mining, for example) . For various reasons I am thinking to switch to SAS/BI area (I am naming SAS because it might be, for me, a possible way to enter in BI). My question, for whoever might have an experience of both: is it, in BI current state, worth it? I mean, the days of big ideas in BI for business seem to be over (there are the APIs, managers think that they know what you can do with them), and my mathematical background might turn out to be superflous. Also, the big companies now have their data organized, have their BI procedures well established, and trying to analyze it from a different standpoint might not be what they want. Another difference is: while in Java etc. development one codes and codes and codes, I don't know if this is the case for BI; in fact, from what I read on the net, a BI (or OLAP, ...etc) developer, in a big organization, is usually in a state of standby, and does in fact little coding. Any opinions, and in particular strong opinions, will be appreciated.

    Read the article

  • Should you create a class within a method?

    - by Amndeep7
    I have made a program using Java that is an implementation of this project: http://nifty.stanford.edu/2009/stone-random-art/sml/index.html. Essentially, you create a mathematical expression and, using the pixel coordinate as input, make a picture. After I initially implemented this in serial, I then implemented it in parallel due to the fact that if the picture size is too large or if the mathematical expression is too complex (especially considering the fact that I made the expression recursively), it takes a really long time. During this process, I realized that I needed two classes which implemented the Runnable interface as I had to put in parameters for the run method, which you aren't allowed to do directly. One of these classes ended up being a medium sized static inner class (not large enough to make an independent class file for it though). The other though, just needed a few parameters to determine some indexes and the size of the for loop that I was making run in parallel - here it is: class DataConversionRunnable implements Runnable { int jj, kk, w; DataConversionRunnable(int column, int matrix, int wid) { jj = column; kk = matrix; w = wid; } public void run() { for(int i = 0; i < w; i++) colorvals[kk][jj][i] = (int) ((raw[kk][jj][i] + 1.0) * 255 / 2.0); increaseCounter(); } } My question is should I make it a static inner class or can I just create it in a method? What is the general programming convention followed in this case?

    Read the article

  • Why is math taught "backwards"? [closed]

    - by Yorirou
    A friend of mine showed me a pretty practical Java example. It was a riddle. I got excited and quickly solved the problem. After it, he showed me the mathematical explanation of my solution (he proved why is it good), and it was completely clear for me. This seems like natural approach for me: solve problems, and generalize. This is very familiar to me, I do it all the time when I am programming: I write a function. When I have to write a similar function, I generalize the problem, grab the generic parts, and refactor them to a function, and solve the original problems as a specialization of the general function. At the university (or at least where I study), things work backwards. The professors shows just the highest possible level of the solutions ("cryptic" mathematical formulas). My problem is that this is too abstract for me. There is no connection of my previous knowledge (== reality in my sense), so even if I can understand it, I can't really learn it properly. Others are learning these formulas word-by-word, and get good grades, since they can write exactly the same to the test, but this is not an option for me. I am a curious person, I can learn interesting things, but I can't learn just text. My brain is for storing toughts, not strings. There are proofs for the theories, but they are also really hard to understand because of this, and in most of the cases they are omitted. What is the reason for this? I don't understand why is it a good idea to show the really high level of abstraction and then leave the practical connections (or some important ideas / practical motivations) out?

    Read the article

  • I can write code...but can't design well. Any suggestions?

    - by user396089
    I feel that I am good at writing code in bits and pieces, but my designs really suck. The question is how do I improve my designs (in order to become a better designer). I think schools and colleges do a good job of teaching people as to how to become good at mathematical problem solving, but lets admit the fact that most programs taught at school are generally around 1000 - 2000 lines long, which means that it is mostly an academic exercise and no way reflects the complexity of real world software (a few hundred thousand to millions of lines of code). This is where I believe that even projects like topcoder/project euler also won't be of much help, they might sharpen your mathematical problem solving ability - but you might become a theoretician programmer; someone who is more interested in the nice, clean stuff, and someone who is utterly un-interested in the day to day mundane and hairy stuff that most application programmers deal with. So my question is how do I improve my design skills? That is the ability to design small/medium scale applications that will go into a few thousand of lines of code? How can I learn design skills that would help me build a better html editor kit, or some graphics program like gimp?

    Read the article

< Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >