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  • Stata - Multiple rotated plots on graph (including distributions on sides of axes)

    - by meerak
    I would like to produce a single graph containing both: (1) a scatter plot (2) either histograms or kernel density functions of the Y and X variables to the left of the Y axis and below the X axis. I found a graph that does this in MATLAB -- I would just like to produce something similar in Stata: That graph was produced using the following MATLAB code: n = 1000; rho = .7; Z = mvnrnd([0 0], [1 rho; rho 1], n); U = normcdf(Z); X = [gaminv(U(:,1),2,1) tinv(U(:,2),5)]; [n1,ctr1] = hist(X(:,1),20); [n2,ctr2] = hist(X(:,2),20); subplot(2,2,2); plot(X(:,1),X(:,2),'.'); axis([0 12 -8 8]); h1 = gca; title('1000 Simulated Dependent t and Gamma Values'); xlabel('X1 ~ Gamma(2,1)'); ylabel('X2 ~ t(5)'); subplot(2,2,4); bar(ctr1,-n1,1); axis([0 12 -max(n1)*1.1 0]); axis('off'); h2 = gca; subplot(2,2,1); barh(ctr2,-n2,1); axis([-max(n2)*1.1 0 -8 8]); axis('off'); h3 = gca; set(h1,'Position',[0.35 0.35 0.55 0.55]); set(h2,'Position',[.35 .1 .55 .15]); set(h3,'Position',[.1 .35 .15 .55]); colormap([.8 .8 1]); UPDATE: The Stata13 manual entry for "graph combine" has precisely this example (http://www.stata.com/manuals13/g-2graphcombine.pdf). Here is the code: use http://www.stata-press.com/data/r13/lifeexp, clear generate loggnp = log10(gnppc) label var loggnp "Log base 10 of GNP per capita" scatter lexp loggnp, ysca(alt) xsca(alt) xlabel(, grid gmax) fysize(25) saving(yx) twoway histogram lexp, fraction xsca(alt reverse) horiz fxsize(25) saving(hy) twoway histogram loggnp, fraction ysca(alt reverse) ylabel(,nogrid) xlabel(,grid gmax) saving(hx) graph combine hy.gph yx.gph hx.gph, hole(3) imargin(0 0 0 0) graphregion(margin(l=22 r=22)) title("Life expectancy at birth vs. GNP per capita") note("Source: 1998 data from The World Bank Group")

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  • How to acquire still webcam image

    - by Silv3rSurf
    I need some help deciding what to use to acquire an image from a webcam. I want to acquire a single image. I know you can typically acquire a still image at a higher resolution than a single video frame. Currently, I am using MATLAB's image acquisition toolbox.. which apparently only supports obtaining frames in video mode(so lower resolution). Which other libraries do you recommend? Has anyone else encountered this problem?

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  • General method for making sub arrays around a particular element

    - by JJ
    What is a quick, elegant way of using MatLab to form a subarray around a particular element? Element are selected randomly from the data, so you can't take a subarray in the normal way (it has to be generalized for the elements that are selected). What I mean is, forming an array for example 5x5 or 7x7 or something, where the middle element is the one you want.

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  • Machine learning - training step

    - by palau1
    When you're using Haar-like features for your training data for an Adaboost algorithm, how do you build your data sets? Do you literally have to find thousands of positive and negative samples? There must be a more efficient way of doing this... I'm trying to analyze images in matlab (not faces) and am relatively new to image processing.

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  • How to still webcam image

    - by Silv3rSurf
    I need some help deciding what to use to acquire an image from a webcam. I want to acquire a single image. I know you can typically acquire a still image at a higher resolution than a single video frame. Currently, I am using MATLAB's image acquisition toolbox.. which apparently only supports obtaining frames in video mode(so lower resolution). Which other libraries do you recommend? Has anyone else encountered this problem?

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  • Efficient process SQL Server and numerical methods library

    - by darkcminor
    Is there a way to comunicate a numeric method library, that can exploit all .net's (numerical methods called by .net that does SQL Server things) habilities?, What library do you recomend, maybe using MATLAB, R? How to comunicate SQL Server and .net with such library or libraries? Do you have an example? What steps must be followed to make the link between numerical libraries, .net and SQL Server

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  • Does Python/Scipy have a firls( ) replacement (i.e. a weighted, least squares, FIR filter design)?

    - by delicasso
    I am porting code from Matlab to Python and am having trouble finding a replacement for the firls( ) routine. It is used for, least-squares linear-phase Finite Impulse Response (FIR) filter design. I looked at scipy.signal and nothing there looked like it would do the trick. Of course I was able to replace my remez and freqz algorithsm, so that's good. On one blog I found an algorithm that implemented this filter without weighting, but I need one with weights. Thanks, David

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  • Runge-Kutta Method with adaptive step

    - by infoholic_anonymous
    I am implementing Runge-Kutta method with adaptive step in matlab. I get different results as compared to matlab's own ode45 and my own implementation of Runge-Kutta method with fixed step. What am I doing wrong in my code? Is it possible? function [ result ] = rk4_modh( f, int, init, h, h_min ) % % f - function handle % int - interval - pair (x_min, x_max) % init - initial conditions - pair (y1(0),y2(0)) % h_min - lower limit for h (step length) % h - initial step length % x - independent variable ( for example time ) % y - dependent variable - vertical vector - in our case ( y1, y2 ) function [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ) % core functionality performed within loop k1 = h * f(x,y); k2 = h * f(x+h/2, y+k1/2); k3 = h * f(x+h/2, y+k2/2); k4 = h * f(x+h, y+k3); ka = (k1 + 2*k2 + 2*k3 + k4)/6; y = y + ka; end % constants % relative error eW = 1e-10; % absolute error eB = 1e-10; s = 0.9; b = 5; % initialization i = 1; x = int(1); y = init; while true hy = y; hx = x; %algorithm [ k1, k2, k3, k4, ka, y ] = iteration( f, h, x, y ); % error estimation for j=1:2 [ hk1, hk2, hk3, hk4, hka, hy ] = iteration( f, h/2, hx, hy ); hx = hx + h/2; end err(:,i) = abs(hy - y); % step adjustment e = abs( hy ) * eW + eB; a = min( e ./ err(:,i) )^(0.2); mul = a * s; if mul >= 1 % step length admitted keepH(i) = h; k(:,:,i) = [ k1, k2, k3, k4, ka ]; previous(i,:) = [ x+h, y' ]; %' i = i + 1; if floor( x + h + eB ) == int(2) break; else h = min( [mul*h, b*h, int(2)-x] ); x = x + keepH(i-1); end else % step length requires further adjustments h = mul * h; if ( h < h_min ) error('Computation with given precision impossible'); end end end result = struct( 'val', previous, 'k', k, 'err', err, 'h', keepH ); end The function in question is: function [ res ] = fun( x, y ) % res(1) = y(2) + y(1) * ( 0.9 - y(1)^2 - y(2)^2 ); res(2) = -y(1) + y(2) * ( 0.9 - y(1)^2 - y(2)^2 ); res = res'; %' end The call is: res = rk4( @fun, [0,20], [0.001; 0.001], 0.008 ); The resulting plot for x1 : The result of ode45( @fun, [0, 20], [0.001, 0.001] ) is:

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  • values from different fields in matalb

    - by ariel
    Hi does anybody familiar with a way that I could implement a matrix with values from a field (not the real or complex number, but lets say Z mod p). so I could perform all the operation of matlab on the matrix (with the values of the chosen field) Ariel

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  • how to convert the Interger date format into YYYYMMDD?

    - by ccfenix
    Python and Matlab quite often have integer date representations as follows: 733828.0 733829.0 733832.0 733833.0 733834.0 733835.0 733836.0 733839.0 733840.0 733841.0 these numbers correspond to some dates this year. Do you guys know which function can convert them back to YYYYMMDD format? thanks a million!

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  • How can i interpret a time value in ascii into a numerical value?

    - by Bilal
    I have a file which is as follows: 15:03:21 II 0.88 0.64 15:03:31 II 0.88 0.64 15:03:42 II 0.40 0.40 etc. after loading the file in matlab, I want to be able to read the first column (which corresponds to time) and interpret them as numerical values. At the moment, they are interpreted as a string of ascii characters and i can't perform any mathematical operations on them. Does anyone have any suggestions as to how i can read the time as numbers instead of a string of ascii characters?

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  • Complex Calculations

    - by mson
    What are the best tools (most efficient) available in .NET (C#) for calculating: integrals partial derivatives other non-trivial math Can people please comment on Mathematica and Matlab and their integration into C#?

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  • Why does file have to be saved prior to running ?

    - by ldigas
    In MATLAB, why does the file have to be saved prior to running ? I often try quick snippets of code, which I could also easily run also on the Command Window line by line. So, why when I run them through the editor, I have to save them first ? Can this behaviour be changed, maybe ?

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  • Add multiple hist fit to a figure, without the hist

    - by clowny
    Hello, I'm a matlab newbie, and i'd like to superpose some hist fit on a same figure. I know the function histfit, but unfortunatly i can't get to remove the hist and only keep the curve. I guess once i'll know how to do that i'll be able to add several curves using "hold on". Thanx for any answers or advices!

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  • How to do motion tracking of a object using video

    - by Niroshan
    Could someone direct me to a tutorial or guide me how to track motion of a object moving with 6 DOF. I am planing to use a video stream of a moving toy car. I want to calculate displacement and rotation angle of the toy car. I came across some research papers but couldn't find any libraries to the job. Is there a way to do this using OpenCV or Matlab or some other freely available software? Thank you

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  • Analyzing data for noisy arrays

    - by jimbo
    Using MATLAB I filtered a very noisy m x n array with a low-pass Gaussian filter, cleaned it up pretty well but still not well enough to analyze my data. What would the next step be? I'm thinking that signal enhancement, but am not sure how to go about this.

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  • thresholding to distinguish small features in noisy data

    - by Daniel
    Hi, I'm wondering what type of threshold would work well for distinguishing features that are very small (small in the xy sense) in comparison with the full spread, if that makes sense. The graythresh() function in Matlab that uses the Otsu method doesn't work too well for my data. Otsu is a clustering method where I think the # of pixels should be similar in each class, which is not the case for me so when I employ it I get a threshold that is way too small and falls well within a lot of the background noise that remains even after filtering.

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  • How can the crosshair of ginput be restricted to one plot?

    - by Lucas
    I wrote a small MATLAB program with a gui. Inside the gui I have, among other things, a plot in which the user should be able to select two points. For this I use the function ginput, which creates a crosshair for selection. Unfortunatley the crosshair extends the whole window and is not restricted to the plot, which doesn't look nice and is confusing for the user. How can the crosshair be restricted only to the area of the plot?

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  • matplotlib equivalent for MATLABs truesize()

    - by Lucas
    I am new to matplotlib and python and would like to display an image so that 1 pixel of the image is actually represented by 1 pixel in the figure. In MATLAB, this is achieved with the command truesize(). How can I do this in Python? I tried playing around with the imshow() arguments as well as set_dpi() and set_figwidth()/set_figheight(), but with no luck. Thanks.

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