Frequency Response Function Plotting

From Control Systems Technology Group

Jump to: navigation, search

Back to Matlab Tools


  • frf.m
  • frfmag.m
  • frfphase.m
  • frfhold.m
  • frflabel.m

Plot Frequency Response Function with
  • Correct label sizes
  • Optimized for MIMO systems
  • Enable use of custom colors (lightgrey, darkgrey, pink, etc.)
  • Adjustable linewidth and marker size
  • Easy to adjust limits
  • Plot only magnitude or phase using the frfmag() and frfphase() functions
  Usage:   frf(sys1,'color/linetype/linewidth/marker/markersize',sys2,'color/linetype/linewidth/marker/markersize',...
  Inputs:  You can use custom colors, e.g. lightgrey, pink, etc. (see line ~315)
           To use the . marker give \. as marker (to distinguist from dots in linewidth specs) 
           example strings: 'lightgrey--1.5o12'    lightgrey dashed line with circle marker of size 12 
                            'orange\.'             orange solid line, dot marker 
                            'b*10'                 blue markers size 10, no line
           All elements in the options-struct are optional
           fmin/fmax in Hz
           magmin/magmax in dB
           phasemin/phasemax in degrees
           wraponoff: [ 'on' | 'off' (default) ]
           type: [ 'mag' | 'phase' | 'magphase' (default) ]
  Outputs: Plots the frf in the current figure.
           Note that the xticklabels might overlap the xlabel in the
           figure. In an exported pdf file they will be correct.

Example frf.m vs bode.m

The size of these example pictures is such that they would fit in a two column formatted page, as in journal and conference papers.



Rob Hoogendijk
Personal tools