octave-online.blogspot.com
OCTAVE Quick Reference: octave_control_bode_phase.m -- Bode Plotting
http://octave-online.blogspot.com/2013/11/bode-bode-plotting-of-transfer-function.html
Octave control bode phase.m - Bode Plotting. Octave control bode phase. Function: [mag, pha, w] = bode. Function: [mag, pha, w] = bode. Bode diagram of frequency response. Function: bode phase plot. A Bode plot is a graph of the transfer function of a linear, time-invariant system versus frequency, plotted with a log-frequency axis, to show the system's frequency response. Octave control nyquist.m. Labels: control bode phase. Octave is primarily intended for numerical computations. Roots of the Polynomial.
maxima-online.blogspot.com
MAXIMA Quick Reference: Fourier transform - plane - square
http://maxima-online.blogspot.com/2013/02/fourier-transform-plane-square.html
Fourier transform - plane - square. Integrate(integrate(1*exp(-%i*2*%pi*(u*x v*y) ,x,-1/2,1/2),y,-1/2,1/2); realpart(%); plot3d(%, [u,-4,4],[v,-4,4],[grid,100,100]);. Fourier transform - 2D integrate(integrate(h(x,y)*exp(-%i*2*%pi*(u*x v*y) ,x,-inf,inf),y,-inf,inf); square h(x,y):= ( unit step( x (1/2) ) - unit step( x-(1/2) ) ) * ( unit step( y (1/2) ) - unit step( y-(1/2) ) ); plot3d(h(x), [x,-10,10],[y, -10, 10]);. Maxima is a Computer Algebra System. Expansion into Partial Fractions. Plot 2D - polar.