Dynamic-Calibration/utils/YALMIP-master/extras/coefficients.m

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2019-12-18 11:25:45 +00:00
function [base,v] = coefficients(p,x,vin)
%COEFFICIENTS Extract coefficients and monomials from polynomials
%
% [c,v] = COEFFICIENTS(p,x) extracts the coefficents
% of a scalar polynomial p(x) = c'*v(x)
%
% c = COEFFICIENTS(p,x) extracts the all coefficents
% of a matrix polynomial.
%
% INPUT
% p : SDPVAR object
% x : SDPVAR object
%
% OUTPUT
% c : SDPVAR object
% v : SDPVAR object
%
% EXAMPLE
% sdpvar x y s t
% p = x^2+x*y*(s+t)+s^2+t^2; % define p(x,y), parameterized with s and t
% [c,v] = coefficients(p,[x y]);
% sdisplay([c v])
%
% See also SDPVAR
if isa(p,'double')
base = p(:);
v = 1;
return
end
if isa(p,'ncvar')
if isa(x,'ncvar')
error('Coefficients not applicable when x is non-commuting');
end
[base,v] = ncvar_coefficients(p,x);
return
end
if nargout>1 & (max(size(p))>1)
error('For matrix inputs, only the coefficients can be returned. Request feature if you need this...');
end
if nargin==1
allvar = depends(p);
xvar = allvar;
x = recover(xvar);
else
xvar = intersect(depends(x),depends(p));
end
% Try to debug this!
p = p(:);
base = [];
for i = 1:length(p)
allvar = depends(p(i));
t = setdiff(allvar,xvar);
if isa(p(i),'double')
base = [base;p(i)];
v = 1;
elseif isa(p(i),'sdpvar')
[exponent_p,p_base] = getexponentbase(p(i),recover(depends(p(i))));
ParametricIndicies = find(ismember(allvar,t));
% FIX : don't define it here, wait until sparser below. Speed!!
tempbase = parameterizedbase(p(i),[],recover(t),ParametricIndicies,exponent_p,p_base,allvar);
[i,j,k] = unique(full(exponent_p(:,find(~ismember(allvar,t)))),'rows');
V = sparse(1:length(k),k,1,length(tempbase),max(k))';
base = [base;V*tempbase];
if nargout == 2
keepthese = j(1:max(k));
v = recovermonoms(exponent_p(keepthese,find(~ismember(allvar,t))),recover(xvar));
end
elseif isa(p,'ncvar')
[exponent_p,ordered_list] = exponents(p,recover(depends(p(i))));
ParametricIndicies = find(ismember(allvar,t));
NotParametricIndicies = find(~ismember(allvar,t));
pars = recover(allvar(ParametricIndicies))';
nonpar = recover(allvar(NotParametricIndicies))';
NonParMonoms = exponent_p(:,NotParametricIndicies);
used = zeros(size(exponent_p,1),1);
for j = 1:size(exponent_p,1)
if ~used(j)
thisMonom = NonParMonoms(j);
thisMonom = 1;
for k = 1:max(find(ordered_list(j,:)))
thisMonom = thisMonom*recover(ordered_list(j,k));
end
thisBase = prod(ordered_list(j,nonpar));
end
end
for j = 1:length(ParametricIndicies)
a = find(ordered_list(:,1) == ParametricIndicies(j))
b = [];
for k = 1:length(a)
b = [b ordered_list(a(k),2:end)]
end
b = b(find(b));
basetemp = [];
for k = 1:length(b)
basetemp = [basetemp ncvar(struct(recover(t((k)))))];
end
base = [base;sum(basetemp)];
end
end
end
if nargout <= 1
v = [];
vin=v;
else
if nargin<3
vin=v;
end
end
if isequal(v,vin)
return
else
for i = 1:length(v)
if isa(v(i),'double')
si(i) = 0;
else
si(i) = getvariables(v(i));
end
end
for i = 1:length(vin)
if isa(vin(i),'double')
vi(i) = 0;
else
vi(i) = getvariables(vin(i));
end
end
newcvals = [];
if all(ismember(si,vi))
for i = 1:length(vin)
where = find(vi(i) == si);
if isempty(where)
newcvals = [newcvals;0];
%newc(i,1) = 0;
else
%newc(i,1) = base(where);
newcvals = [newcvals;base(where)];
end
end
newc = sparse(1:length(vin),ones(length(vin),1),newcvals);
else
error('The supplied basis is not sufficient');
end
base = newc(:);
v = vin(:);
end
function p_base_parametric = parameterizedbase(p,z, params,ParametricIndicies,exponent_p,p_base,allvar)
% Check for linear parameterization
parametric_basis = exponent_p(:,ParametricIndicies);
%if all(sum(parametric_basis,2)==0)
if all(all(parametric_basis==0))
p_base_parametric = full(p_base(:));
return
end
if all(ismember(parametric_basis,[0 1])) & all(sum(parametric_basis,2)<=1)%all(sum(parametric_basis,2)<=1)
p_base_parametric = full(p_base(:));
n = length(p_base_parametric);
ii = [];
vars = [];
js = sum(parametric_basis,1);
for i = 1:size(parametric_basis,2)
if js(i)
j = find(parametric_basis(:,i));
ii = [ii j(:)'];
vars = [vars repmat(i,1,js(i))];
end
end
k = setdiff1D(1:n,ii);
if isempty(k)
p_base_parametric = p_base_parametric.*sparse(ii,repmat(1,1,n),params(vars));
else
pp = params(vars); % Must do this, bug in ML 6.1 (x=sparse(1);x([1 1]) gives different result in 6.1 and 7.0!)
p_base_parametric = p_base_parametric.*sparse([ii k(:)'],repmat(1,1,n),[pp(:)' ones(1,1,length(k))]);
end
else
% Bummer, nonlinear parameterization sucks...
[mt,variabletype,hashedmonoms,hashkey] = yalmip('monomtable');
exponent_p_ParametricIndicies = exponent_p(:,ParametricIndicies);
LocalHash = exponent_p_ParametricIndicies*hashkey(allvar(ParametricIndicies));
[yn,loc] = ismember(LocalHash,hashedmonoms);
something = any(exponent_p_ParametricIndicies,2);
dummy = sdpvar(1);
for i = 1:length(p_base)
%j = find(exponent_p(i,ParametricIndicies));
% j = find(exponent_p_ParametricIndicies(i,:));
if something(i)%~isempty(j)
% temp = 1;%p_base(i);
% quickfind = findhashsorted(hashedmonoms, hashkey(ParametricIndicies(j))'*exponent_p(i,ParametricIndicies(j))');
quickfind = loc(i);
if (quickfind)
%temp = recover(quickfind);
temp = quickrecover(dummy,quickfind,p_base(i));
else
temp = p_base(i);
j = find(exponent_p_ParametricIndicies(i,:));
for k = 1:length(j)
if exponent_p(i,ParametricIndicies(j(k)))==1
temp = temp*params(j(k));
else
temp = temp*params(j(k))^exponent_p(i,ParametricIndicies(j(k)));
end
end
end
xx{i} = temp;
else
xx{i} = p_base(i);
end
end
p_base_parametric = stackcell(sdpvar(1,1),xx)';
end