Back to SYMPHONY Home Page

user_send_lp_solution

 

int user_send_lp_solution(void *user, int varnum, var_desc **vars, 
                          double *x, int where)

Description:

The user has the option to send the LP solution to either the cut pool or the cut generator in some user-defined form if desired. There are two default options--sending the indices and values for all nonzero variables (SEND_NONZEROS) and sending the indices and values for all fractional variables (SEND_FRACTIONS).

Arguments:

Return values:

Wrapper invoked from:

fathom_branch() after an LP relaxation has been solved. The message is always sent to the cut generator (if there is one). The message is sent to the cut pool if a search tree node at the top of a chain is being processed (except at the root in the first phase), or if a given number (cut_pool_check_freq) of LP relaxations have been solved since the last check.

Note:

The wrapper automatically packs the level, index, and iteration number corresponding to the current LP solution within the current search tree node, as well as the objective value and upper bound in case the solution is sent to a cut generator. This data will be unpacked by SYMPHONY on the receiving end, the user will have to unpack there exactly what he has packed here.