XPRSdelcols
XPRSdelcols |
Purpose
Synopsis
int XPRS_CC XPRSdelcols(XPRSprob prob, int ncols, const int mindex[]);
Arguments
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prob
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The current problem.
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ncols
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Number of columns to delete.
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mindex
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Integer array of length
ncols containing the columns to delete.
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Example
In this example, column
3 is deleted from the matrix:
mindex[0] = 3; XPRSdelcols(prob,1,mindex);
Further information
1. After columns have been deleted from a problem, the numbers of the remaining columns are moved down so that the columns are always numbered from
0 to
COLS-1 where
COLS is the problem attribute containing the number of non-deleted columns in the matrix.
2. If the problem has already been optimized, or an advanced basis has been loaded, and you delete a basis column 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 non-basic columns (see XPRSgetbasis), taking a basic column out of the basis first if necessary (see XPRSgetpivots and XPRSpivot).
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 non-basic columns (see XPRSgetbasis), taking a basic column out of the basis first if necessary (see XPRSgetpivots and XPRSpivot).
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