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XPRSrhssa

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Purpose

Returns upper and lower sensitivity ranges for specified right hand side (RHS) function coefficients. If the RHS coefficients are varied within these ranges the current basis remains optimal and the reduced costs remain valid.

Synopsis

int XPRS_CC XPRSrhssa(XPRSprob prob, int nels, const int mindex[], double lower[], double upper[]);

Arguments

prob	The current problem.
nels	Integer and number of RHS coefficients whose sensitivity ranges are sought.
mindex	Integer array of length nels containing the indices of the rows whose RHS coefficients sensitivity ranges are required.
lower	Double array of length nels where the RHS lower range values are to be returned.
upper	Double array of length nels where the RHS upper range values are to be returned.

Example

Here we obtain the RHS function ranges for the three columns: 2, 6 and 8:

mindex[0] = 2; mindex[1] = 8; mindex[2] = 6;
XPRSrhssa(prob,3,mindex,lower,upper);

After which lower and upper contain:

lower[0] = 5.0; upper[0] = 7.0;
lower[1] = 3.8; upper[1] = 5.2;
lower[2] = 5.7; upper[2] = 1e+20;

Meaning that the current basis remains optimal when 5.0 rhs₂, 3.8 rhs₈ 5.2 and 5.7 rhs₆, rhs_i being the RHS coefficient of row i.

Further information

XPRSrhssa can only be called when an optimal solution to the current LP has been found. It cannot be used when the problem is MIP presolved.

Related topics

XPRSobjsa.

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