Errata for Part 4 lecture notes.
Page numbers based on the student version with Neuhoff #s, not Ulrich #s.

p.20
the derivation of the DFT is missing three important 1/N factors in
the last set of displayed equations on this page.

p.23
the derivation of parseval is correct, BUT putting the "N" on the "wrong side"
adds unnecessary confusion.

p.26
there should also be a figure of the "ideal" spectrum with lines corresponding
to +/- 3.2 rads/sample (suitably aliased) with some discussion of the
difference between the ideal spectrum and what is computed by finite DFT.

p.27
the "frequency" axis of the spectrogram should be [0,\pi] or in realistic Hz.
a colorbar() is needed to help quantify the color scale.  (white=0)

p.30
in the first equation (two-sided spectrum), the middle pair should be
	(X[0],0)

p.31
The continuous-time spectrum should be rearranged and labeled from
-5512.5 to 5512.5 Hz, NOT from 0 to 11,025Hz!
(See the discussion on the preceding page.)