CPXcopyctype

The routine CPXcopyctype can be used to copy variable type information to a given problem. Variable types indicate whether a variable is continuous, integer, binary, semi-continuous, or semi-integer. If the type of the problem object is CPXPROB_LP, it is changed to CPXPROB_MILP. If the type of the problem object is CPXPROB_QP, it is changed to CPXPROB_MIQP. If the type of the problem object is CPXPROB_QCP, it is changed to CPXPROB_MIQCP.

This routine allows the types of all the variables to be set in one function call. When CPXcopyctype is called, any current solution information is freed.

Note

Defining a variable j to be binary by setting the corresponding ctype[j]='B' does not change the bounds associated with that variable. Because a call to CPXmipopt fails if the value of the corresponding variable is not between 0 and 1 in the solution of the LP relaxation at the root of the search tree, explicitly setting the bounds of binary variables to 0 and 1 is recommended.

Table 1: Possible values for elements of xctype
`CPX_CONTINUOUS`	`'C'`	continuous variable
`CPX_BINARY`	`'B'`	binary variable
`CPX_INTEGER`	`'I'`	general integer variable
`CPX_SEMICONT`	`'S'`	semi-continuous variable
`CPX_SEMIINT`	`'N'`	semi-integer variable

Example

 status = CPXcopyctype (env, lp, ctype);

See also the example mipex1.c in the standard distribution.

CPXcopyctype

Parameters:

Returns:

env	A pointer to the CPLEX environment as returned by `CPXopenCPLEX`.
lp	A pointer to a CPLEX problem object as returned by `CPXcreateprob`.
xctype	An array of length `CPXgetnumcols(env,lp)` containing the type of each column in the constraint matrix. Possible values appear in Table 1.