xyeval.m

线性时变系统控制器设计的工具包

function vxmat = xyeval(xmat,fparm)

% vxmat = xyeval(xmat,fparm)
% evaluates the matrix function X(p) = X1 f1(p) + ... + Xn fn(p)
% at N grid points.  
% xmat is a VARYING array of matrix coordinate data, and
% fparm is a VARYING array of scalar basis function data, e.g.
% xmat = vpck([X1;...;Xn],1:n) 
% fparm = vpck([[f1(p1) ... fn(p1)] ... [f1(pN);...;fn(pN)]]',1:N)

[mtyp,nr,nc,nbasis] = minfo(xmat);
[ftyp,nrf,ncf,npts] = minfo(fparm);

if mtyp ~= 'vary'
 nbasis = 1;
end
if ftyp ~= 'vary'
 npts = 1;
end
if nbasis ~= max([nrf ncf])
 error('Inconsistent number of basis functions');
elseif min([nrf ncf]) > 1
 error('Basis function data must be vectors');
end

if mtyp ~= 'vary' & ftyp ~= 'vary'
 vxmat = xmat*fparm;
elseif mtyp ~= 'vary'
 vxmat = mmult(xmat,fparm);
else
 vxmat = zeros(npts*nr,nc);
 for k = 1:npts
  X = zeros(nr,nc);
  fdat = xtracti(fparm,k,1);
  for kk = 1:nbasis
   X = X + xtracti(xmat,kk,1)*fdat(kk);
  end
  vxmat(nr*(k-1)+1:nr*k,:) = X;
 end
 if npts > 1,
  vxmat = vpck(vxmat,getiv(fparm));
 end
end