eq.m

HERE IS A GOOD PSO TOOL BOX

function r = eq(lhs,rhs)
% GPOSYNOMIAL/EQ  Implements '==' for generalized posynomials.
%
%   This is only possible when both left and right hand side are
%   generalized posynomials that consist of a single monomial term.
%   (Basically, generalized posynomials are here monomials.)
%

sz1 = size(lhs); sz2 = size(rhs);
if( sz1(1) > 1 & sz1(2) > 1)
  error(['Cannot impose pointwise equality with matrices of general posynomials.' ...
         char(10) 'The pointwise equality is only allowed between vectors.'])
end
if( sz2(1) > 1 & sz2(2) > 1)
  error(['Cannot impose pointwise equality with matrices of general posynomials.' ...
         char(10) 'The pointwise equality is only allowed between vectors.'])
end
if( sz1(1) ~= sz2(1) || sz1(2) ~= sz2(2))
  error(['Cannot make pointwise equality between vectors ' ...
         'with incompatible dimensions.'])
end

% constructing a single equality
if( length(lhs) == 1 & length(rhs) == 1 )

  % check if lhs is a monomial
  if ismonomial(lhs)
    % now get that monomial via eval command with empty input
    lhs = eval(lhs, {'' []});
  else
    error('Not a valid GP equality: left hand side has to be a monomial.');
  end

  % now check what is the rhs
  if isnumeric(rhs)
    rhs = rhs;
  elseif ismonomial(rhs)
    rhs = eval(rhs, {'' []});
  else
    error('Not a valid GP equality: right hand side has to be a monomial.')
  end

  % create a GP equality constraint
  r = gpconstraint(lhs,'==',rhs);
  return;
end

% pointwise equality between vectors
if( sz1(1) == 1 & sz2(1) == 1 )
  for k = 1:sz1(2)
    r(1,k) = lhs(1,k) == rhs(1,k);
  end
  return;
end

if( sz1(2) == 1 & sz2(2) == 1 )
  for k = 1:sz1(1)
    r(k,1) = lhs(k,1) == rhs(k,1);
  end
  return;
end