XPRSgetmqobj, XPRSgetmqobj64
XPRSgetmqobj, XPRSgetmqobj64 |
Purpose
Returns the nonzeros in the quadratic objective coefficients matrix for the columns in a given range. To achieve maximum efficiency,
XPRSgetmqobj returns the lower triangular part of this matrix only.
Synopsis
int XPRS_CC XPRSgetmqobj (XPRSprob prob, int mstart[], int mclind[], double dobjval[], int size, int *nels, int first, int last);
int XPRS_CC XPRSgetmqobj64 (XPRSprob prob, XPRSint64 mstart[], int mclind[], double dobjval[], XPRSint64 size, XPRSint64 *nels, int first, int last);
Arguments
|
prob
|
The current problem.
|
|
mstart
|
Integer array which will be filled with indices indicating the starting offsets in the
mclind and
dobjval arrays for each requested column. It must be length of at least
last-first+2. Column
i starts at position
mstart[i] in the
mrwind and
dmatval arrays, and has
mstart[i+1]-mstart[i] elements in it. May be NULL if
size is
0.
|
|
mclind
|
Integer array of length
size which will be filled with the column indices of the nonzero elements in the lower triangular part of
Q. May be
NULL if
size is
0.
|
|
dobjval
|
Double array of length
size which will be filled with the nonzero element values. May be
NULL if
size is
0.
|
|
size
|
The maximum number of elements to be returned (size of the arrays).
|
|
nels
|
Pointer to an integer where the number of nonzero quadratic objective coefficients will be returned. If the number of nonzero coefficients is greater than
size, then only
size elements will be returned. If
nels is smaller than
size, then only
nels will be returned.
|
|
first
|
First column in the range.
|
|
last
|
Last column in the range.
|
Further information
The objective function is of the form
cTx+0.5xTQx where
Q is positive semi-definite for minimization problems and negative semi-definite for maximization problems. If this is not the case the optimization algorithms may converge to a local optimum or may not converge at all. Note that only the upper or lower triangular part of the
Q matrix is returned.
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