# How to plot 2D and 3D (CWT) spectrograms

**URL:** https://discourse.paraview.org/t/how-to-plot-2d-and-3d-cwt-spectrograms/7964
**Category:** ParaView Support
**Tags:** python
**Created:** [September 9, 2021, 4:13pm UTC](https://discourse.paraview.org/t/how-to-plot-2d-and-3d-cwt-spectrograms/7964 "2021-09-09T16:13:36Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Sam](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/s/5f9b8f/32.png) [@Sam](https://discourse.paraview.org/u/Sam)
#### Post date: [September 9, 2021, 4:13pm UTC](https://discourse.paraview.org/t/how-to-plot-2d-and-3d-cwt-spectrograms/7964/1 "2021-09-09T16:13:36Z")

</div>

Hi  
I’m want to draw 2D and 3D spectrograms for these two files with paraview (based on Continuous Wavelet Transform (CWT) and mother wavelet: cmor ) my signal frequency is 128Hz.  
Would you please guide me to know how I can do that?  
my data doesn’t have time step and I encounter this error:  
“no time steps in input data!”  
[1 (1).csv](https://discourse.paraview.org/uploads/short-url/eclzaRCcJH8tIctU7PNQrUC9C5G.csv) (3.1 MB)  
[1 (2).csv](https://discourse.paraview.org/uploads/short-url/rrofXoga8ahZ3JUapPnzrlGYk1N.csv) (3.1 MB)