I did get some good work done today though. I figured out the flaw in the windowing methods. It was returning a list of zeros because each term was being multiplied by a null. Having fixed that, I realised that I was asking it to graph the curve of the window rather than the window applied to an FFT. That too was fixed and now each window method prints a graph. I believe the graphs are incorrect, but at least something is shown.
Each window function when called on their own (as opposed to together through the compare option) seems to be the same as the FFT without windowing. The Hanning window is a little different, but it doesn't get rid of the leakage. If anything, it adds more.
When called together, something is still off. The Hanning window looks the same, but the others lose several values towards the end of the frequency spectrum.
Comparison of FFT Graphs(Click on the image to see a larger, more legible version)
In this process a few other things got accomplished. I got rid of the mirroring of graphs the was seen yesterday. I had been only plotting the first half of the FFT values, thinking that would get rid of the mirroring. It turns out that it did and the image was mirrored twice, so I now plot only the first quarter of the FFT. Not sure why this is true. I'll do some research into that at a later date.
I also discovered that there were two float arrays with the same data but different names floating around (no pun intended) After some searching I found that the doFFT() method rewrites the float array it is given with the FFT values and returning a second version of that array. That has been remedied.
Another big change in the code is that it no longer writes to Text files. That was getting confusing as it had to write over the same file each time, so the information is stored in a float array in the FFT class that is passed to the GraphingData class to be graphed. That cleaned up the code quite a bit.
The last change was to change the if-else loops that dealt with the menu choice and which window to use are now switch-case blocks. I just find that it's neater. I also added a try-catch block around the menu's switch-case blocks to keep it from crashing.
So maybe today wasn't that unproductive, quite a lot got updated if not fixed, but it felt it because the windows still do not work right. That's top of my list tomorrow. Again.
I'm going to end today with some research into what I should add to this next. Assuming that the windows are fixed and working tomorrow, I will need something else to do for next week.
I also discovered that there were two float arrays with the same data but different names floating around (no pun intended) After some searching I found that the doFFT() method rewrites the float array it is given with the FFT values and returning a second version of that array. That has been remedied.
Another big change in the code is that it no longer writes to Text files. That was getting confusing as it had to write over the same file each time, so the information is stored in a float array in the FFT class that is passed to the GraphingData class to be graphed. That cleaned up the code quite a bit.
The last change was to change the if-else loops that dealt with the menu choice and which window to use are now switch-case blocks. I just find that it's neater. I also added a try-catch block around the menu's switch-case blocks to keep it from crashing.
So maybe today wasn't that unproductive, quite a lot got updated if not fixed, but it felt it because the windows still do not work right. That's top of my list tomorrow. Again.
I'm going to end today with some research into what I should add to this next. Assuming that the windows are fixed and working tomorrow, I will need something else to do for next week.
Ah, yes there is more to do. I'll go through this code with you tomorrow
ReplyDelete