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getdblattrib

Purpose

Get the value of an SLP double (real) attribute

Synopsis

function getdblattrib(Type:string, Param:integer|string) :real

Arguments

Type	A character string beginning with "L" for the linear problem or "M" for the MIP (integer) problem in MISLP
Param	The number or name of the required parameter. The number is given in the header file for the corresponding Xpress module (for example, xprs.h or xslp.h). If the name is used, it must be preceded by "XSLP_" or "XPRS_" as appropriate (for example, "xslp_errorcosts" or "xprs_lpobjval").

Return value

The current value of the attribute (parameter set by the system) in the appropriate problem

Example

The following code fragment from a callback within a MISLP optimization prints the current best bound:

writeln("Best bound = ",getdblattrib("M",2004)))

2004 is parameter xprs_bestbound

Further information

The get...control and get...attrib functions are identical to getparam for the linear problem (Type="L"). During MISLP, MIP-specific information must be retrieved from the MIP problem (Type="M") because the linear problem is solving only subproblems and is not in MIP mode. Note that the required parameter can be specified as an integer or as a name. Specifying as an integer is generally more efficient. The value corresponding to a particular parameter can be found in the header file for the appropriate module (xprs.h or xslp.h). This function is also useful for setting parameters which have not been defined by name in the Mosel system.