I've implemented the basic version of discrete Fourier Transform and I'm testing it using a pure sinusoid. However, small bumps show up in addition to the large peak. I tried Numpy.fft for this and I got the exact same height for the largest peak, so I'm pretty confident that my implementation is correct. However, I think I might be missing the step of squashing the small bumps. What tools can I use to squash them? I haven't seen anyone explicitly talk about this.