## 4 Badges

9 years, 328 days

## @Carl Love  Thanks! Ok! My main p...

Thanks!

Ok! My main problem is numerical integration. Is it possible to reduce computation time? What about parallel computing? Matrix elements are independent, may be I should divide matrix into several sub-matrices to use several threads?

## @gkokovidis Thank you for your answ...

@gkokovidis Thank you for your answer. Everything is clear.

## @acer No. There isn't....

@acer No. My main question is "solved".

But I discovered an interesting thing. If I use "zcoloring" in plots:-surfdata everything is OK. But if I use plots:-listdensityplot comand I obtain the following figure:

```plots:-listdensityplot(res, style=patchnogrid, smooth=false,
colorscheme = ["zcoloring", [z -> r(f(z)), z -> g(f(z)), z -> b(f(z))],
colorspace = "RGB"]);
```

Why????

## Oh! I found mistake. I use to evaluate ...

Oh! I've just found mistake. I use to evaluate maximum value from input matrix and simultaneously use b(t) as a function of blue color.

Spectrogram_zcoloring_correct.mw

## Hello everyone again!I realized all of m...

Hello everyone again!

I realized all of my mistakes in previos algorithm, and wrote correct version of all metioned above functions using Welch algorithm: Power Spectral Density Estimation, Cross Power Spectral Density Estimation, Coherence between two signals.

I offer for your attention program, which you can find all these functions as procedures.

I attached program which results obtained with my Maple programm and Matlab built-in functions (pwelch, cpsd, mscohere) are compared. So, 5 attached files: Maple_programm, input signals for Matlab and Maple, power spectral density from matlab for signal1, cross power spectral density from matlab, coherence from matlab.

Spectral_density-maple_VS_matlab.mw

cpsd_test_mbin.txt

psd_test_mbout.txt

cpsd_test_mbout.txt

coh_test_mbout.txt

## @mmcdara Thank you for your answer....

Thank you for your answer. I realized my mistake. So, if i want to compute cross power spectral density i have to write "CrossCorrelation" path of algorithm on my own.

If you are interested in full algorithm for Cross Power Spectral Density and Coherence you can see my answer above.

Yes, it is.

## Continuous wavelet transform...

I have one request. Please add сontinuous wavelet transform (CWT) as an alternative to Short-time Fourier transform in Spectrogram command from SignalProcessing

## @acer Thanak you for your answer. ...

@acer Thanak you for your answer.

But this approach doesn't work, because execution continues. I want to stop execution before "a:=1;". Moreover if I use done/quit/stop I'll get error.

Error, done/quit/stop disabled. Please use File->Close

## @acer  Thank you very much. Your a...

Thank you very much. Your answers are good food for thought.

## @acer Thank you very much! You advi...

Thank you very much! Your advice is useful for me.

Could you give me another concil — about colors in listcontplot. Is it possible to choose colors in this command?

## @acer Thank you for your answer....

@acer Thank you for your answer.

## @Kitonum  What about scale? If I w...

What about scale? If I want plot something like that: "plot [sin(x)/10^5, cos(x)+2.4, 1.2]". It seems your solution is not appropriate in this case.

## @Axel Vogt  I didn't catch you...

I didn't catch your idea. Could you give simple example, please?

If it is interesting I add my experimental data. First column is time, second and third are signal1 and signal2 respectively.

Plot_example.txt

## @Christopher2222  "What happe...

"What happened to your question regarding most efficient way to parse?"

> I don't know.

"Yes you can create graphs like that in Maple.  Just for fun without the scale it appears a is just smoothed b, b is some squared or doubled of c."

> Hm. I would like to visualize experimental data. So, I have got for example Matirx(n,m), where the first column is time and others are experimental signals. It would be great if I could plot experimental signals like on my "example picture".

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