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comparison m-toolbox/classes/@pzmodel/fromRational.m @ 0:f0afece42f48

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Import.
author Daniele Nicolodi <nicolodi@science.unitn.it>
date Wed, 23 Nov 2011 19:22:13 +0100
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-1:000000000000 0:f0afece42f48
1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2 %
3 % FUNCTION: fromRational
4 %
5 % DESCRIPTION: Construct a pzmodel from a rational TF
6 %
7 % CALL: pzm = fromRational(a, pl)
8 %
9 % PARAMETER: pl - plist
10 %
11 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
12 function pzm = fromRational(pzm, pli)
13
14 VERSION = '$Id: fromRational.m,v 1.12 2011/08/15 12:20:52 hewitson Exp $';
15
16
17 % get pzmodel info
18 ii = pzmodel.getInfo('pzmodel', 'From Rational');
19
20 % Set the method version string in the minfo object
21 ii.setMversion([VERSION '-->' ii.mversion]);
22
23 % Combine input plist with default values
24 pl = applyDefaults(ii.plists, pli);
25
26 % Set fields
27 rat = find(pl, 'rational');
28
29 poles = roots(rat.den);
30 zeros = roots(rat.num);
31
32 % remove conjugate pairs
33 if isempty(poles)
34 ps = [];
35 else
36 ps = {poles(1)};
37 for jj=2:numel(poles)
38 if ~isreal(poles(jj))
39 if~any(conj(poles(jj))==[ps{:}])
40 ps = [ps poles(jj)];
41 end
42 else
43 ps = [ps poles(jj)];
44 end
45 end
46 end
47
48 if isempty(zeros)
49 zs = [];
50 else
51 zs = {zeros(1)};
52 for jj=2:numel(zeros)
53 if ~isreal(zeros(jj))
54 if~any(conj(zeros(jj))==[zs{:}])
55 zs = [zs zeros(jj)];
56 end
57 else
58 zs = [zs zeros(jj)];
59 end
60 end
61 end
62
63 % get gain - must be a nicer way, but...
64 ig = abs(resp(rat, plist('f', 0)));
65
66 % divide for (-2*pi) only when a real pole or zero is found
67 if ~isempty(ps)
68 numps = cell2mat(ps);
69 numps(imag(numps)==0) = numps(imag(numps)==0)/(-2*pi);
70 ps = num2cell(numps);
71 end
72 if ~isempty(zs)
73 numzs = cell2mat(zs);
74 numzs(imag(numzs)==0) = numzs(imag(numzs)==0)/(-2*pi);
75 zs = num2cell(numzs);
76 end
77
78 % convert to pzmodel
79 pzm = pzmodel(ig.data.getY, ps, zs);
80
81 % Override some plist values using the input object
82 if isempty(pl.find('ounits'))
83 pl.pset('ounits', rat.ounits);
84 end
85
86 if isempty(pl.find('iunits'))
87 pl.pset('iunits', rat.iunits);
88 end
89
90 if isempty(pl.find('name'))
91 pl.pset('name', sprintf('pzmodel(%s)', rat.name));
92 end
93
94 if isempty(pl.find('description'))
95 pl.pset('description', rat.description);
96 end
97
98 % Add history
99 pzm.addHistory(ii, pl, [], rat.hist);
100
101 % Set object properties
102 pzm.setObjectProperties(pl);
103
104 end