DFT calculations returning different results My coworker ran a DFT query using a software in C downloaded to his PC. His results was the following chart:


I am using a JS tool from corbanbrook/dsp.js

My results were very different.


any ideas why, or where to look?
Make sure you use the same scaling and X and Y axis so you compare apples to apples. The upper graph is in power the lower seems to be amplitude
Start with a known signal with a known answer. A sine wave or square wave for example and compare the outcome with the expected result.