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Oct
1
comment My Baum-Welch algorithm is very slow. Is it due to Mathematica?
(Just so you know, some of these comments are automatically generated from the /review queue). To commenters and flaggers: the "commentness" of the answer is noted and I think we all (including Igor) agree on that. However, Igor also has a valid point that the link does answer the question fully and reproducing the code there (which is a lot) is kinda futile. Please participate in the meta discussion if you have thoughts/more to say on this. I will not be deleting this answer.
Oct
1
comment My Baum-Welch algorithm is very slow. Is it due to Mathematica?
That is a lot of code for anyone on this site to have time to read/critique/analyze it fully and most likely, no one is going to. However from a quick glance at the code, I can most certainly say that the slowness is due to the procedural programming style. All those Sum[Sum[Sum[Sum... terms in nested Whiles are bound to give terrible performance. Writing the algorithm in a functional manner would certainly speed things up a lot. Unfortunately, it is hard (for me at least) to recommend specific changes to make to your code. If I were you, I'd start afresh with functional (use Igor's link)
Oct
1
revised My Baum-Welch algorithm is very slow. Is it due to Mathematica?
added 59 characters in body
Sep
30
awarded  Explainer
Sep
30
awarded  Refiner
Sep
20
comment Converting code from Matlab to Mathematica
I wrote an implementation of k-means in this answer.
Sep
19
awarded  Generalist
Sep
17
comment Is garbage collection broken in version 10.0.0?
I don't have 10.0.1 or Mathematica with me now, but what you're describing doesn't seem unexpected. I think if you re-evaluate the top cell a second time, you should see {"foo$"} in the output.
Sep
16
comment How do I plot the images of oriented curves under complex transformation?
I used to have a "systematic way to obtain a nice parametrization of an arbitrary conic" — it was called "Ask J. M." :)
Sep
15
comment How do I bandpass a signal in Mathematica 8
@Mr.Wizard No, sorry. It's a lot of time commitment and detail that's well beyond the scope of this site. OP still hasn't replied to my question re: MATLAB. If that's the case, then the second example here would be the best way to proceed.
Sep
15
comment How do I bandpass a signal in Mathematica 8
A crude filtering could be done with Fourier, a window and InverseFourier. If you want to use specific FIR/IIR filters with certain guarantees of performance in the pass/stop bands, then you're going to have to write a lot of the code yourself. If you have access to MATLAB (and the DSP toolbox), then I suggest using the functions from it in Mathematica 8.
Sep
14
comment Generating random symmetric matrix
Ah, yes of course.
Sep
14
comment Generating random symmetric matrix
Why not just do $M = (A + A^T)/2$? I understand that while the elements are iid, the diagonals and off-diagonals have different variances, but if you're primarily concerned with the eigenvalue statistics, this should be a faster way of generating the matrices. The eigenvalues of this and your matrix should both be Wigner distributed.
Sep
9
awarded  Announcer
Sep
8
comment Show only the outlines of graphic primitives
You can also use c_?ColorQ so that Hue, CMYKColor, GrayLevel, etc. are all recognized.
Sep
7
awarded  Good Answer
Sep
7
revised How can I visualize an array of very small vectors spaced on very large grid?
appended answer 59088 as supplemental
Sep
3
awarded  Good Answer
Aug
30
comment Hypergeometric function with a matrix argument
The paper has pseudocode that is fairly easy to read and implement, so perhaps you can translate it to Mathematica?
Aug
29
awarded  Good Answer