[Eeglablist] Problem with inverse transform

[Makoto Miyakoshi]

Dear Franzi,

I did not know there is such a thing as inverse short-term Frourier
Transformation, but I can see it should work.
First of all, you have to share the error message so that we can guess the
cause of the problem better.
That said, judging from your comment,

> Also, I'm not sure if the input requires complex data or data already
transformed to power.

most likely you did not understand the required input type and your input
was wrong. The input must be 3-D complex data. See this page. Note 'Input
arguments' can be found AFTER 'Examples' (strange!)
https://urldefense.com/v3/__https://www.mathworks.com/help/signal/ref/istft.html*mw_df6a90fa-0796-411d-ab9c-d86cc3c0edec_sep_mw_f4653206-42e2-4878-82ba-66875c98c86c__;Iw!!Mih3wA!H7QLYv7nSTdwJrG_4fGNP0eV4b4XW-NVNWLV872UQPC3mzT29zQNAnKNKSA54Svi0sLM59alPwfeIRPh0nYfPq0nHpw$ 

Good luck!

Makoto

On Fri, Jul 28, 2023 at 8:30 PM Franziska Kirsch via eeglablist <
eeglablist at sccn.ucsd.edu> wrote:

> Dear List Members,
>
> currently I am trying to inverse transform data in time-frequency space
> back to time domain. I have used the istft - function (inverse short time
> Fourier transform) from Matlab, but it does not seem to work. I keep
> getting error messages about problems with the input data, even though it
> should be correct (as the function says ‚matrix with time increasing across
> the columns and frequency increasing down the rows‘). Also, I'm not sure if
> the input requires complex data or data already transformed to power.
>
> Another idea is to calculate it manually and multiply a complex sine wave
> by the complex Fourier coefficient and sum the results.
>
> Any recommendations on how to achieve an inverse transform? Thank you in
> advance for your help!
>
> Yours sincerely,
> Franzi Kirsch
>
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