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XPRSdelrows

Purpose

Delete rows from a matrix.

Synopsis

               int XPRS_CC XPRSdelrows(XPRSprob prob, int nrows, const int mindex[]);
               

Arguments

prob	The current problem.
nrows	Number of rows to delete.
mindex	An integer array of length nrows containing the rows to delete.

Example

In this example, rows 0 and 10 are deleted from the matrix:

mindex[0] = 0; mindex[1] = 10;
XPRSdelrows(prob,2,mindex);

Further information

1. After rows have been deleted from a problem, the numbers of the remaining rows are moved down so that the rows are always numbered from 0 to ROWS-1 where ROWS is the problem attribute containing the number of non-deleted rows in the matrix.

2. If the problem has already been optimized, or an advanced basis has been loaded, and you delete a row for which the slack column is non-basic, the current basis will no longer be valid - the basis is "lost". If you go on to re-optimize the problem, a warning message is displayed (140) and the Optimizer automatically generates a corrected basis.
You can avoid losing the basis by only deleting basic rows (see XPRSgetbasis), bringing a non-basic row into the basis first if necessary (see XPRSgetpivots and XPRSpivot).