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comparison scripts/control/system/syssub.m @ 4771:b8105302cfe8

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[project @ 2004-02-16 17:45:50 by jwe]
author jwe
date Mon, 16 Feb 2004 17:45:50 +0000
parents 0d411821682c
children bdbee5282954
comparison
equal deleted inserted replaced
4770:ef5e598f099b 4771:b8105302cfe8
47 if(nargin < 1) 47 if(nargin < 1)
48 usage("syssub: sys = syssub(Gsys{,Hsys,...})"); 48 usage("syssub: sys = syssub(Gsys{,Hsys,...})");
49 endif 49 endif
50 50
51 ## collect all arguments 51 ## collect all arguments
52 arglist = list(); 52 arglist = {};
53 for kk=1:nargin 53 for kk=1:nargin
54 arglist(kk) = varargin{kk}; 54 arglist{kk} = varargin{kk};
55 if(!isstruct(nth(arglist,kk))) 55 if(!isstruct(arglist{kk}))
56 error("syssub: argument %d is not a data structure",kk); 56 error("syssub: argument %d is not a data structure",kk);
57 endif 57 endif
58 endfor 58 endfor
59 59
60 ## check system dimensions 60 ## check system dimensions
61 [n,nz,mg,pg,Gyd] = sysdimensions(nth(arglist,1)); 61 [n,nz,mg,pg,Gyd] = sysdimensions(arglist{1});
62 for kk=2:nargin 62 for kk=2:nargin
63 [n,nz,mh,ph,Hyd] = sysdimensions(nth(arglist,kk)); 63 [n,nz,mh,ph,Hyd] = sysdimensions(arglist{kk});
64 if(mg != mh) 64 if(mg != mh)
65 error("arg 1 has %d inputs; arg %d has vs %d inputs",mg,kk,mh); 65 error("arg 1 has %d inputs; arg %d has vs %d inputs",mg,kk,mh);
66 elseif(pg != ph) 66 elseif(pg != ph)
67 error("arg 1 has %d outputs; arg %d has vs %d outputs",pg,kk,ph); 67 error("arg 1 has %d outputs; arg %d has vs %d outputs",pg,kk,ph);
68 elseif(norm(Gyd - Hyd)) 68 elseif(norm(Gyd - Hyd))
71 endif 71 endif
72 endfor 72 endfor
73 73
74 ## perform the subtract 74 ## perform the subtract
75 if(nargin == 2) 75 if(nargin == 2)
76 Gsys = nth(arglist,1); Hsys = nth(arglist,2); 76 Gsys = arglist{1};
77 Hsys = arglist{2};
77 if( strcmp(sysgettype(Gsys),"tf") | strcmp(sysgettype(Hsys),"tf") ) 78 if( strcmp(sysgettype(Gsys),"tf") | strcmp(sysgettype(Hsys),"tf") )
78 ## see if subtracting transfer functions with identical denominators 79 ## see if subtracting transfer functions with identical denominators
79 [Gnum,Gden,GT,Gin,Gout] = sys2tf(Gsys); 80 [Gnum,Gden,GT,Gin,Gout] = sys2tf(Gsys);
80 [Hnum,Hden,HT,Hin,Hout] = sys2tf(Hsys); 81 [Hnum,Hden,HT,Hin,Hout] = sys2tf(Hsys);
81 if(length(Hden) == length(Gden) ) 82 if(length(Hden) == length(Gden) )
82 if( (Hden == Gden) & (HT == GT) ) 83 if( (Hden == Gden) & (HT == GT) )
83 sys = tf2sys(Gnum-Hnum,Gden,GT,Gin,Gout); 84 sys = tf(Gnum-Hnum,Gden,GT,Gin,Gout);
84 return 85 return
85 endif 86 endif
86 ## if not, we go on and do the usual thing... 87 ## if not, we go on and do the usual thing...
87 endif 88 endif
88 endif 89 endif
104 105
105 sys = sysscale (sys, [eyout, -eyout], [eyin; eyin], Gout, Gin); 106 sys = sysscale (sys, [eyout, -eyout], [eyin; eyin], Gout, Gin);
106 107
107 else 108 else
108 ## multiple systems (or a single system); combine together one by one 109 ## multiple systems (or a single system); combine together one by one
109 sys = nth(arglist,1); 110 sys = arglist{1};
110 for kk=2:length(arglist) 111 for kk=2:length(arglist)
111 sys = syssub(sys,nth(arglist,kk)); 112 sys = syssub(sys,arglist{kk});
112 endfor 113 endfor
113 endif 114 endif
114 115
115 endfunction 116 endfunction