bodegraph

A few small modifications to Robert Papanicola's BodeGraph package.

• Fixed a bug where \POAmpAsymp{a}{b} generates a blank plot for b >= 2.

• Added support for asymptotic Bode plots of real poles and zeros in the right half plane.

• Added support for asymptotic Bode plots of complex conjugate pairs of poles and zeros with negative ζ.

• When loaded using the option linear:

  • \POArgAsymp changes slopes a decade before and after a pole/zero.
  • \SOArgAsymp changes slopes at ω_n/10^ζ and 10^ζω_n.

• Due to a bug in gnuplot, using a negative sign, -\POArgAsymp and -\SOArgAsymp, to plot zeros does not work unless they are subtracted from something. For example, \POArgAsymp{1}{1}-\POArgAsymp{10}{10} is OK, and so is 0-\POArgAsymp{10}{10}+\POArgAsymp{1}{1}. But, -\POArgAsymp{10}{10}+\POArgAsymp{1}{1} does not work.

• Call \BodeGraph with the option samples=300 (or more, as needed) to get accurate asymptotic phase plots.