function [C,A,b,blk] = dsdpdata(F,h)
%DSDPDATA Internal function create DSDP data

if ~(isempty(F) | isa(F,'lmi'))
help lmi
error('First argument (F) should be an lmi object. See help text above');
end

if ~(isempty(h) | isa(h,'sdpvar'))
help solvesdp
error('Third argument (the objective function h) should be an sdpvar object (or empty). See help text above');
end

[ProblemString,real_data] = catsdp(F);
if (real_data == 0)
error('DSDP does not support complex data')
end

% This one is used a lot
nvars = sdpvar('nvars');

% Convert the objective
onlyfeasible = 0;
if isempty(h)
c=zeros(nvars,1);
else
[n,m]=size(h);
if ~((n==1) & (m==1))
error('Scalar expression to minimize please.');
else
lmi_variables = getvariables(h);
c = zeros(nvars,1);
for i=1:length(lmi_variables)
c(lmi_variables(i))=getbasematrix(h,lmi_variables(i));
end;
end
end

[F_struc,K,F_blksz] = lmi2spstruct(F);

% Which sdpvar variables are actually in the problem
used_variables_LMI = find(any(F_struc(:,2:end),1));
used_variables_obj = find(any(c',1));
used_variables = uniquestripped([used_variables_LMI used_variables_obj]);

% Check for unbounded variables
unbounded_variables = setdiff(used_variables_obj,used_variables_LMI);
if ~isempty(unbounded_variables)
% Remove unbounded variable from problem
used_variables = setdiff(used_variables,unbounded_variables);
end

% Pick out the necessary rows
if length(used_variables)<nvars
c = c(used_variables);
F_struc = sparse(F_struc(:,[1 1+[used_variables]]));
end

if (K.f>0)
% Extract the inequalities
A_equ = F_struc(1:K.f,2:end);
b_equ = -F_struc(1:K.f,1);

% Find feasible (turn off annoying warning on PC)
% Using method from Nocedal-Wright book
showprogress('Solving equalities',options.ShowProgress);
[Q,R] = qr(A_equ');
n = size(R,2);
Q1 = Q(:,1:n);
R = R(1:n,:);
x_equ = Q1*(R'\b_equ);
% Exit if no consistent solution exist
if (norm(A_equ*x_equ-b_equ)>sqrt(eps))
error('Linear constraints inconsistent.');
return
end
% We dont need the rows for equalities anymore
F_struc = F_struc(K.f+1:end,:);
K.f = 0;

% We found a new basis
H = Q(:,n+1:end); % New basis

% objective in new basis
c = H'*c;
% LMI in new basis
F_struc = [F_struc*[1;x_equ] F_struc(:,2:end)*H];
else
% For simpliciy we introduce a dummy coordinate change
x_equ = 0;
H = 1;
end

% Convert from SP format (same format as SDPT3-2.3)
[C,A,b,blk] = sp2sdpt323(F_struc,F_blksz,c);