calcbasis.m

线性时变系统控制器设计的工具包

function [fparm,gparm,gradf,gradg] = calcbasis(parmvec,basisfunc)

% function [fparm,gparm,gradf,gradg] = calcbasis(parmvec,'basisfunc')
%
%   Evaluates basis functions and gradients at desired parameter points.  
% Inputs:  parmvec	varying matrix of parameter values
% 	   'basisfunc'	string containing the name of a function
%			evaluating the basis functions and gradients.
%
% Outputs: fparm	varying matrix of values for f
%	   gparm	varying matrix of values for g
%	   gradf	varying matrix of values for df/drho
%	   gradg	varying matrix of values for dg/drho
%
% basisfunc.m should have the syntax 
%	[fdef,gdef,gfdef,ggdef] = func(rho)
% as shown below:
%
% Consider R-dimensional parameters and N basis functions:
% fdef = [f1(parm);f2(parm);...;fN(parm)];
% gfdef = [df1/dparm1 df1/dparm2 ... df1/dparmR;
%          df2/dparm1 df2/dparm2 ... df2/dparmR;
%              .         .               . 
%              .         .               . 
%              .         .               . 
%          dfN/dparm1 dfN/dparm2 ... dfN/dparmR];
% and similarly for gdef, ggdef.
%
% For example:
% fdef = [1; parmi(3); parmi(3)^2; parmi(3)^3];
% gdef = fdef;
% gfdef = [0 0 0; 0 0 1; 0 0 2*parmi(3); 0 0 3*parmi(3)^2];
% ggdef = gfdef;

if nargin == 0
 disp('usage: [fparm,gparm,gradf,gradg] = calcbasis(parmvec,''basisfunc'')');
 return
end

[mtype,row,col,npts] = minfo(parmvec);
if mtype == 'vary'
 tmp = xtracti(parmvec,1,1);
 if min(size(tmp)) ~= 1
  error('Parameter must be a vector');
 end
elseif mtype == 'cons'
 if min(size(parmvec)) ~= 1
  error('Parameter must be a vector');
 end
 parmvec = vpck(parmvec,1);
 npts = 1;
else
 error('Parameter data must constant or varying vector');
end

fparm = [];
gparm = [];
gradf = [];
gradg = [];

for i=1:npts
  parmi = xtracti(parmvec,i,1);

  % Call the evaulating function
  eval(['[fdef,gdef,gfdef,ggdef] = ' basisfunc '(parmi);']);

  fparm = [fparm;fdef];
  gparm = [gparm;gdef];
  gradf = [gradf;gfdef];
  gradg = [gradg;ggdef];
end
iv = getiv(parmvec);
fparm = vpck(fparm,iv);
gparm = vpck(gparm,iv);
gradf = vpck(gradf,iv);
gradg = vpck(gradg,iv);