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XPRSchgcoef

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Purpose

Used to change a single coefficient in the matrix. If the coefficient does not already exist, a new coefficient will be added to the matrix. If many coefficients are being added to a row of the matrix, it may be more efficient to delete the old row of the matrix and add a new row.

Synopsis

int XPRS_CC XPRSchgcoef(XPRSprob prob, int irow, int icol, double dval);

Arguments

prob	The current problem.
irow	Row index for the coefficient.
icol	Column index for the coefficient.
dval	New value for the coefficient. If dval is zero, any existing coefficient will be deleted.

Related Controls

Double

MATRIXTOL

Zero tolerance on matrix elements.

Example

In the following, the element in row 2, column 1 of the matrix is changed to 0.33:

XPRSchgcoef(prob,2,1,0.33);

Further information

XPRSchgmcoef is more efficient than multiple calls to XPRSchgcoef and should be used in its place in such circumstances.

Related topics

XPRSaddcols, XPRSaddrows, XPRSchgmcoef, XPRSchgmqobj, XPRSchgobj, XPRSchgqobj, XPRSchgrhs, XPRSgetcols, XPRSgetrows.

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