Axtell's Notes: June 23

So we haven't gotten to the constant Q transformation yet. Hopefully that will start tomorrow. I fixed a bunch of bugs in BigGUI and FFTGUI today. Some of them have error popups when it is something that the user should fix (such as not putting in a number for the sample size.)

I added a zoom in FFTGUI like BigGUI's, and I'm working on adding a scrolling function for both of them so we can zoom into any part of the spectrum. FFTGUI had a few problems with windows. Namely mousing over the windowed function's graph changed it to the un-windowed FFT, and zooming did the same thing. Both are fixed, though when the FFTGUI is called from BigGUI, the FFT that first appears is un-windowed and the mouse moves onto it, it changes to the window. I think I need to look at scaling for the windows because the windowed values are so much smaller than the un-windowed FFT that they look like straight lines.

We changed the 2D double array that held the data to a 3D array so that all the peaks that were in the same sample could be plotted in the same x location.

a440 With Hanning Window

The last thing I did was to update the function that determines what color to make each point. I wrote completely separate algorithms for the Hanning and Hamming windows because their data is so much smaller than the un-windowed FFT or Bartlett.

I also did some clean up and commenting of all the code I had written thus far, and ran all of Maple Leaf Rag with and with and without windows. Each took about 10 minutes.

We will actually start work on the constant Q transformation tomorrow! I'll also fix whatever problems come up with BigGUI.