Rank: 3781 based on 7 downloads (last 30 days) and 2 files submitted
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Changqing Xu

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Image processing, computation

 

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15 May 2010 a short code for creating a random (1,-1) matrix This is a very short code file for creating a random matrix whose entries are either 1 or -1. Author: Changqing Xu random matrix, binary, singularity, determinant 1 2
  • 1.0
1.0 | 2 ratings
20 Nov 2008 Matrix Permanent Computation of matrix permanent Author: Changqing Xu matrix, permanent, configuration 6 0
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02 Aug 2009 MAGIC - MATLAB Generic Imaging Component Tutorial GUI to demonstrate basic functionality of various controls on the GUI Author: Mark Hayworth

Great! A nice display on how to use gui to play vedio
12 Nov 2008 Video: GUIDE Basics Tutorial Five minute video about building GUIs in MATLAB. Author: Doug Hull
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18 May 2010 a short code for creating a random (1,-1) matrix This is a very short code file for creating a random matrix whose entries are either 1 or -1. Author: Changqing Xu Jos (10584)

Indeed poorly coded using an unnecessary double-for loop (with pre-allocation though!), limited to 2D sqaure matrices only.

A vectorized, (too!) simple and flexible approach:

function R = rand01(varargin)
% H1 line goes here
% help goes here
R = 2*(rand(varargin{:})>0.5)-1 ;
17 May 2010 a short code for creating a random (1,-1) matrix This is a very short code file for creating a random matrix whose entries are either 1 or -1. Author: Changqing Xu Tursa, James

This submission has the following problems:
1) It uses a double for loop to individually fill in each element of the resulting matrix rather than using vectorized code.
2) It uses the relatively expensive power operator to generate the +1 and -1 values.
3) The H1 line function name does not match the actual function name.
4) A much faster (more than 3x faster) one-liner equivalent to this submission is as follows: floor(rand(n)*2)*2-1
5) There is no provision for non-square or multi-dimensional sizes. Only square 2D sizes are supported.

James Tursa
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binary, configuration, determinant, matrix, movie
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15 May 2010 a short code for creating a random (1,-1) matrix This is a very short code file for creating a random matrix whose entries are either 1 or -1. Author: Changqing Xu random matrix, binary, singularity, determinant 1 2
  • 1.0
1.0 | 2 ratings
19 Jun 2009 Screenshot MAGIC - MATLAB Generic Imaging Component Tutorial GUI to demonstrate basic functionality of various controls on the GUI Author: Mark Hayworth demo, gui example, gui, play, batch processing, movie 72 1
  • 4.0
4.0 | 7 ratings
20 Nov 2008 Matrix Permanent Computation of matrix permanent Author: Changqing Xu matrix, permanent, configuration 6 0

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