Fourier transform

Fourier transform - Mathcad Fourier transform doesn't work in SMath - Messages

#1 Posted: 2026/5/14 16:19:57
Caro

Caro

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Dear all,

I have a Mathcad Document about Fourier transform that I want to translate into SMath.
I already dowloaded the FFTPack plugin. I used the same functions from the Mathcad document which doesn't work in SMath.
I tried a bit but nothing is working. The error message says "The argument must be a scalar."
I attached screenshots from my SMath document and the original Mathcad document.

Does anyone have an idea or a helpful tip?

Thanks in advance

Screenshot 2026-05-14 181146.png
Screenshot 2026-05-14 180252.png
#2 Posted: 2026/5/14 16:26:36
Caro

Caro

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fft_spalt_test.sm (5.42 KiB) downloaded 144 time(s).
#3 Posted: 2026/5/14 18:55:58
sergio

sergio

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try to construct the vector like this

Show Spoiler


sergio
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Caro 2026/5/15 07:01:47
#4 Posted: 2026/5/15 07:07:59
Caro

Caro

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Thank you! That worked and the error message is gone.

I'm still having trouble plotting the graph. The graph is not being displayed but there isn't any error message.
Did I overlook something? Does the rfft() function work different in SMath than in Mathcad?

Thanks in advance
#5 Posted: 2026/5/15 07:57:42
sergio

sergio

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Check if it can help you. The graph has the correct shape but the values are different.fft_spalt_test(sergio).sm (10.62 KiB) downloaded 127 time(s).
sergio
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Caro 2026/5/15 16:30:00
#6 Posted: 2026/5/15 16:32:47
Caro

Caro

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Thank you Sergio!

I'm going to try around with your file a bit more. But having the correct shape is already very helpful and good enough.

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