New 3d Graph Tool

The new 3d graph tool does not show the full frequency resolution of an FFT. Ie I perform a 1Hz resolution FFT on some data, plot it on a 2d chart and I can see a result every 1Hz. Using the old 3d graph tool (officially obsolete) I also see a bar for every spectral line. The new 3d graph shows a frequency result only every 176Hz.

Does anyone know a way to make the new 3d graph tool show the full resolution of the data?

Hi,

when zoomed out we are showing an intermediate buffer that is also why the resolution is not that good.

If we would show a direct buffer when for longer periods of time, the memory consumption would increase. You can increase it in the settings by increasing the Maximum vector size for IB buffer.

If the problem is still present, you can also share the file with us and we can check it.

Thanks for the advice. I'm not short of memory as the pc has 32GB RAM and a 4GB GPU. However, I cranked the store buffer up to 2048 without getting a noticeable change in frequency resolution; also tried increasing the Video memory to 256MB and forcing dewesoft to use the gpu. No change. I certainly can't find a way to show the full resolution of the FFT (unlike with the old 3d chart tool). It's good to be able to see the whole file as a 3d surface and it's a good indicative display, but without the full time and frequency resolution it's of little use for measurements.

What parameters for "video memory" and "max vector size" would you suggest? Also is the FFT math parameter "History Size (3d graph)" still relevant?

Hi,

if you set the IB buffer to the same number as the number of lines in the FFT, Dewesoft will keep the resolution in the frequency axis. to increase the time before the intermediate buffer is shown, you can also try increasing the asynchronous DB buffer length.

If you can share the data file with us and tell us how much time you would like to show on the graph, we can also check the parameters here.

Thanks I'm starting to understand what's going on now!

If found that the maximum permitted IB bufer is 10000 and max Async Buffer is 512. At a sample rate of 50kS/s the FFT will always extend to 25000Hz even if I'm only interested in the part from 6kHz to 7kHz; at a 1Hz resolution I would need 25000 points, so in this case,10000 is not enough!! However, I tested the idea with 10000 points and a 5Hz FFT resolution, now it works within those limits.