Rank: 80 based on 482 downloads (last 30 days) and 39 files submitted
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Computers assist human.
I do ignore all emails related to questions of the Answers forum.

Professional Interests:
Motion analysis, physics, orthopedics

 

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Files Posted by Jan View all
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(last 30 days) 		Comments Rating
04 Nov 2011 Screenshot WindowAPI Set figure size, top-most, transparency and pixel mask, multi-monitor etc by Windows API Author: Jan Simon figure, alpha, blending, stencil, maximize, minimize 36 8
  • 4.75
4.8 | 4 ratings
03 Nov 2011 GetFullPath Full path name for partial or relative path Author: Jan Simon full, name, path, file, qualified, parent directory 22 9
  • 5.0
5.0 | 5 ratings
01 Nov 2011 Screenshot CmdWinTool Programmatic control of the command window Author: Jan Simon command window, maximize, minimize, statusbar, menubar, multimonitor 10 1
  • 5.0
5.0 | 1 rating
01 Nov 2011 Screenshot anyExceed Fast test for out of range elements, C-mex Author: Jan Simon statistics, data exploration, cmex, any, exceed, limit 9 1
01 Nov 2011 Screenshot anyEq Fast check if 2 arrays have a common element Author: Jan Simon any, equal, isequal, compare, common element, cmex 8 2
Comments and Ratings by Jan View all
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04 Feb 2012 Sum ofall numbers in the input vector for cody challenge Author: Santhana Raj

This submission is not useful, because it simply calls "sum(x)" for its input.
I assume you want to test the curiosity of the other users.
19 Jan 2012 Merge sorted arrays Given two already sorted arrays, the function combines them in an unique sorted array Author: Bruno Luong

@Tal: C++ comments are accepted in the C99 style. Only C89 does not consider them, but this standard is 23 years old now.
18 Jan 2012 Fast moving average A fast implementation of the moving average filter for long kernels. Author: Christian Kothe

Mentioning the targetted window size is important. Now the purpose of the function is clearer. Thanks for the improvements!
14 Jan 2012 Fast moving average A fast implementation of the moving average filter for long kernels. Author: Christian Kothe

This is a nice function for educational purpose. It contains a documentation and can operate on a specified dimension.
It fails for scalar inputs - improving the detection of the first non-singelton dimension is required.

But the calculations are not "fast":
x = rand(1e6, 1);
tic; y = moving_average(10, x); toc
>> 0.213 sec
tic; y2 = filter(repmat(1/10, 1, 10), 1, x); toc
>> 0.057 sec
And using an improved FILTER function is further 50% faster.
03 Jan 2012 Rotate vector(s) about axis Rotate three-dimensional vector(s) about a specified axis by a specified angle. Author: Ismail Hameduddin

This function has a H1 line and a compact and sufficient documentation of input, outputs, required subfunctions, date and contact address. The size of the input is checked.
Instead of "crosskv = v;" you can start with "crosskv(3) = ..." for the pre-allocation.
It would be nice, if the function accepts [N x 3] arrays also.
The function is small, but useful and usable.
Comments and Ratings on Jan's Files View all
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28 Dec 2011 FilterM A faster FILTER and FILTFILT: Speedup factor 2.5 to 25 Author: Jan Simon Avital, Royi

@Jan, try even longer filters. I'd be happy if you could release an update for long FIR's even before the threaded version.
It would be great!

Thank you for this great function.
27 Dec 2011 FilterM A faster FILTER and FILTFILT: Speedup factor 2.5 to 25 Author: Jan Simon Simon, Jan

@Royi Avital: The currently published version does not consider the reduced calculations for FIR filters. I get these measurements for 2011b/64 under Windows, MSVC 2008:
x=rand(1e5, 1); B=repmat(1/21, 1, 21);
tic; for i=1:100, y=filter(B,1,x); clear('y'); end, toc
>> 0.56 sec
tic; for i=1:100, y=FilterX(B,1,x); clear('y'); end, toc
>> 0.42 sec (still faster)
The new version of FilterX considers A=1 explicitely and requires 0.27 sec only. It will be included in the next version, which is multi-threaded also. See: http://www.mathworks.com/matlabcentral/answers/24384-multi-threaded-mex-functions-in-the-fex
27 Dec 2011 FilterM A faster FILTER and FILTFILT: Speedup factor 2.5 to 25 Author: Jan Simon Avital, Royi

@Jan, for FIR Filters with more than 20 coefficients FilterM lags behind MATLAB's implementation.
Do you think you could optimize for longer filters as well?
Thank you.
20 Dec 2011 FilterM A faster FILTER and FILTFILT: Speedup factor 2.5 to 25 Author: Jan Simon Simon, Jan

Sorry, currently only real values are considered. The implementation of a complex parameters is not trivial in C. It is planned later.
20 Dec 2011 FilterM A faster FILTER and FILTFILT: Speedup factor 2.5 to 25 Author: Jan Simon Avital, Royi

Jan, there's an issue with complex coefficients, Could you check that?

I'm using the MEX file directly (For "Classic" use as Filter).

Thank you.
Top Tags Applied by Jan
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cmex, mex, string, statistics, array
Files Tagged by Jan View all
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Updated   File Tags Downloads
(last 30 days) 		Comments Rating
04 Nov 2011 Screenshot WindowAPI Set figure size, top-most, transparency and pixel mask, multi-monitor etc by Windows API Author: Jan Simon figure, alpha, blending, stencil, maximize, minimize 36 8
  • 4.75
4.8 | 4 ratings
03 Nov 2011 GetFullPath Full path name for partial or relative path Author: Jan Simon full, name, path, file, qualified, parent directory 22 9
  • 5.0
5.0 | 5 ratings
01 Nov 2011 Screenshot CmdWinTool Programmatic control of the command window Author: Jan Simon command window, maximize, minimize, statusbar, menubar, multimonitor 10 1
  • 5.0
5.0 | 1 rating
01 Nov 2011 Screenshot anyExceed Fast test for out of range elements, C-mex Author: Jan Simon statistics, data exploration, cmex, any, exceed, limit 9 1
01 Nov 2011 Screenshot anyEq Fast check if 2 arrays have a common element Author: Jan Simon any, equal, isequal, compare, common element, cmex 8 2

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