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lib/Math/LP.pm  view on Meta::CPAN

        Math::LP::Solve::set_obj_fn($lprec,$this->make_coeff_array($this->{objective_function}));
	if   ($this->{type} == $MAX) { Math::LP::Solve::set_maxim($lprec); }
	elsif($this->{type} == $MIN) { Math::LP::Solve::set_minim($lprec); }
	else {
	    $this->croak('No objective function type ($MAX or $MIN) set for solving');
	}
    }
    
    return $lprec;
}
sub update_variable_values { # copies the variable values to the variable objects
    my Math::LP $this = shift;
    my $lprec = shift;
    
    # the variable values are found in the solution vector
    my $solution = Math::LP::Solve::lprec_best_solution_get($lprec);

    # The index offset is explained as follows
    #   + 1          because of the objective function value
    #   + nr_rows()  because of the slacks
    #   - 1          because the 1st variable has index 1, not 0
    my $offset = $this->nr_rows(); 

    # copy the appropriate value for each variable
    foreach(values %{$this->{variables}}) {
	my $var_index = $_->{col_index};
	$_->{value} = Math::LP::Solve::ptrvalue($solution,$offset+$var_index);
    }
}
sub update_slacks {
    my Math::LP $this = shift;
    my $lprec = shift;
    
    # the slacks are fetched from the solution vector
    my $solution = Math::LP::Solve::lprec_best_solution_get($lprec);

    # copy the appropriate slack for each constraint
    foreach(@{$this->{constraints}}) {
	my $row_index = $_->{row_index};

lib/Math/LP.pm  view on Meta::CPAN

        # The real slack is easily derived from the lhs value.
	$_->{slack} = $_->{rhs} - $buggy_slack;
    }

    # Also fetch the objective function value
    if(defined($this->{objective_function})) {
	$this->{objective_function}->{value} = Math::LP::Solve::ptrvalue($solution,0);
    }
}
sub update_dual_values {
    my Math::LP $this = shift;
    my $lprec = shift;

    # the dual values are fetched from the duals vector
    my $duals = Math::LP::Solve::lprec_duals_get($lprec);

    # copy the appropriate dual value for each constraint
    foreach(@{$this->{constraints}}) {
	my $row_index = $_->{row_index};
	$_->{dual_value} = Math::LP::Solve::ptrvalue($duals,$row_index)