Mercurial > octave-nkf

comparison scripts/control/base/nichols.m @ 6448:2110cc251779

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[project @ 2007-03-24 02:47:36 by jwe]
author jwe
date Sat, 24 Mar 2007 02:47:36 +0000
parents 34f96dd5441b
children 9483da8d87e5
comparison
equal deleted inserted replaced
6447:3f79532415b5 6448:2110cc251779
66 ## @item w 66 ## @item w
67 ## The vector of frequency values used. 67 ## The vector of frequency values used.
68 ## @end table 68 ## @end table
69 ## If no output arguments are given, @command{nichols} plots the results to the screen. 69 ## If no output arguments are given, @command{nichols} plots the results to the screen.
70 ## Descriptive labels are automatically placed. See @command{xlabel}, 70 ## Descriptive labels are automatically placed. See @command{xlabel},
71 ## @command{ylabel}, @command{title}, and @command{replot}. 71 ## @command{ylabel}, and @command{title}.
72 ## 72 ##
73 ## Note: if the requested plot is for an @acronym{MIMO} system, @var{mag} is set to 73 ## Note: if the requested plot is for an @acronym{MIMO} system, @var{mag} is set to
74 ## @iftex 74 ## @iftex
75 ## @tex 75 ## @tex
76 ## $ \Vert G(jw) \Vert $ or $ \Vert G( {\rm exp}(jwT) \Vert $ 76 ## $ \Vert G(jw) \Vert $ or $ \Vert G( {\rm exp}(jwT) \Vert $
83 ## @end deftypefn 83 ## @end deftypefn
84 84
85 function [mag, phase, w] = nichols (sys, w, outputs, inputs) 85 function [mag, phase, w] = nichols (sys, w, outputs, inputs)
86 86
87 ## check number of input arguments given 87 ## check number of input arguments given
88 if (nargin < 1 | nargin > 4) 88 if (nargin < 1 || nargin > 4)
89 print_usage (); 89 print_usage ();
90 endif 90 endif
91 if(nargin < 2) 91 if (nargin < 2)
92 w = []; 92 w = [];
93 endif 93 endif
94 if(nargin < 3) 94 if (nargin < 3)
95 outputs = []; 95 outputs = [];
96 endif 96 endif
97 if(nargin < 4) 97 if (nargin < 4)
98 inputs = []; 98 inputs = [];
99 endif 99 endif
100 100
101 [f, w, sys] = __bodquist__ (sys, w, outputs, inputs, "nichols"); 101 [f, w, sys] = __bodquist__ (sys, w, outputs, inputs, "nichols");
102 102
103 [stname,inname,outname] = sysgetsignals(sys); 103 [stname,inname,outname] = sysgetsignals (sys);
104 systsam = sysgettsam(sys); 104 systsam = sysgettsam (sys);
105 105
106 ## Get the magnitude and phase of f. 106 ## Get the magnitude and phase of f.
107 mag = abs(f); 107 mag = abs (f);
108 phase = arg(f)*180.0/pi; 108 phase = arg (f)*180.0/pi;
109 109
110 if (nargout < 1), 110 if (nargout < 1),
111 ## Plot the information 111 ## Plot the information
112 oneplot(); 112
113 __gnuplot_set__ autoscale; 113 if (max (mag) > 0)
114 __gnuplot_set__ nokey; 114 plot (phase, 20 * log10 (mag));
115 clearplot(); 115 ylabel ("Gain in dB");
116 grid("on"); 116 else
117 __gnuplot_set__ data style lines; 117 plot (phase, mag);
118 if(is_digital(sys)) 118 ylabel ("Gain |Y/U|")
119 endif
120
121 grid ("on");
122
123 if (is_digital (sys))
119 tistr = "(exp(jwT)) "; 124 tistr = "(exp(jwT)) ";
120 else 125 else
121 tistr = "(jw)"; 126 tistr = "(jw)";
122 endif 127 endif
123 xlabel("Phase (deg)"); 128
124 if(is_siso(sys)) 129 xlabel ("Phase (deg)");
125 title(["Nichols plot of |[Y/U]",tistr,"|, u=", ... 130
126 sysgetsignals(sys,"in",1,1), ", y=",sysgetsignals(sys,"out",1,1)]); 131 if (is_siso (sys))
132 title (sprintf ("Nichols plot of |[Y/U]%s|, u=%s, y=%s", tistr,
133 sysgetsignals (sys, "in", 1, 1),
134 sysgetsignals (sys, "out", 1, 1));
127 else 135 else
128 title([ "||Y(", tistr, ")/U(", tistr, ")||"]); 136 title ([ "||Y(", tistr, ")/U(", tistr, ")||"]);
129 printf("MIMO plot from\n%s\nto\n%s\n",__outlist__(inname," "), ... 137 printf ("MIMO plot from\n%s\nto\n%s\n", __outlist__ (inname, " "),
130 __outlist__(outname," ")); 138 __outlist__ (outname, " "));
131 endif
132 if(max(mag) > 0)
133 ylabel("Gain in dB");
134 md = 20*log10(mag);
135 else
136 ylabel("Gain |Y/U|")
137 md = mag;
138 endif 139 endif
139 140
140 axvec = axis2dlim([vec(phase),vec(md)]); 141 axis (axis2dlim ([phase(:), md(:)]));
141 axis(axvec); 142
142 plot(phase,md);
143 mag = phase = w = []; 143 mag = phase = w = [];
144 endif 144 endif
145
145 endfunction 146 endfunction