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XPRSdelrows

Purpose
Delete rows from a matrix.
Topic area
Problem Creation
Synopsis
int XPRS_CC XPRSdelrows(XPRSprob prob, int nrows, const int rowind[]);
Arguments
prob 
The current problem.
nrows 
Number of rows to delete.
rowind 
An integer array of length nrows containing the rows to delete.
Example
In this example, rows 0 and 10 are deleted from the matrix: 
rowind[0] = 0; rowind[1] = 10;
XPRSdelrows(prob,2,rowind);
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).
3. This function cannot be called while the current problem is being solved or when it is in an interrupted state. Use XPRSpostsolve to restore the problem to a non-solving state.
Related topics
XPRSaddrows, XPRSdelcols, XPRSgetbasis, XPRSgetpivots, XPRSpivot.

Parent Topic Console and Library Functions

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