CPXXgetbase and CPXgetbase

The routine CPXXgetbase/CPXgetbase accesses the basis resident in a CPLEX problem object.

int CPXXgetbase( CPXCENVptr env, CPXCLPptr lp, int * cstat, int * rstat )

int CPXgetbase( CPXCENVptr env, CPXCLPptr lp, int * cstat, int * rstat )

Description

The routine CPXXgetbase/CPXgetbase accesses the basis resident in a CPLEX problem object. Either of the arguments cstat or rstat may be NULL if only one set of status values is needed.

Table 1. Table 1: Values of elements of cstat
`CPX_AT_LOWER`	`0`	variable at lower bound
`CPX_BASIC`	`1`	variable is basic
`CPX_AT_UPPER`	`2`	variable at upper bound
`CPX_FREE_SUPER`	`3`	variable free and nonbasic

Table 2. Table 2: Values of elements of rstat in rows other than ranged rows
`CPX_AT_LOWER`	`0`	associated slack, surplus, or artificial variable is nonbasic at value 0.0 (zero)
`CPX_BASIC`	`1`	associated slack, surplus, or artificial variable is basic

Table 3. Table 3: Values of elements of rstat for ranged rows
`CPX_AT_LOWER`	`0`	associated slack, surplus, or artificial variable is nonbasic at its lower bound
`CPX_BASIC`	`1`	associated slack, surplus, or artificial variable is basic
`CPX_AT_UPPER`	`2`	associated slack, surplus, or artificial variable is nonbasic at upper bound

Arguments

env: A pointer to the CPLEX environment as returned by CPXXopenCPLEX/CPXopenCPLEX.
lp: A pointer to a CPLEX problem object as returned by CPXXcreateprob/CPXcreateprob.
cstat: An array to receive the basis status of the columns in the CPLEX problem object. The length of the array must be no less than the number of columns in the matrix. The array element cstat[i] has the meaning specified in Table 1.
rstat: An array to receive the basis status of the artificial, slack, or surplus variable associated with each row in the constraint matrix. The length of the array must be no less than the number of rows in the CPLEX problem object. For rows other than ranged rows, the array element rstat[i] has the meaning specified in Table 2. For ranged rows, the array element rstat[i] has the meaning specified in Table 3.

Return

The routine returns 0 (zero) if a basis exists. It returns nonzero if no solution exists or any other type of error occurs.

Example


status = CPXgetbase (env, lp, cstat, rstat);

See also the example lpex2.c in the examples distributed with the product.