SdpVarfixer.c File Reference

adds the main functionality to fix/unfix/(multi-)aggregate variables by merging two three-tuple-arrays of row/col/val together More...

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Functions
void	SCIPsdpVarfixerSortRowCol (int *row, int *col, SCIP_Real *val, int length)
SCIP_RETCODE	SCIPsdpVarfixerMergeArrays (BMS_BLKMEM *blkmem, SCIP_Real feastol, int *originrow, int *origincol, SCIP_Real *originval, int originlength, SCIP_Bool originsorted, SCIP_Real scalar, int *targetrow, int *targetcol, SCIP_Real *targetval, int *targetlength, int targetmemory)
SCIP_RETCODE	SCIPsdpVarfixerMergeArraysIntoNew (BMS_BLKMEM *blkmem, SCIP_Real feastol, int *firstrow, int *firstcol, SCIP_Real *firstval, int firstlength, int *secondrow, int *secondcol, SCIP_Real *secondval, int secondlength, int *targetrow, int *targetcol, SCIP_Real *targetval, int *targetlength)

Detailed Description

adds the main functionality to fix/unfix/(multi-)aggregate variables by merging two three-tuple-arrays of row/col/val together

Author

Tristan Gally

Definition in file SdpVarfixer.c.

Function Documentation

void SCIPsdpVarfixerSortRowCol	(	int *	row,
		int *	col,
		SCIP_Real *	val,
		int	length
	)

sort the given row, col and val arrays first by non-decreasing row-indices, then for those with identical row-indices by non-decreasing col-indices

Parameters

row	row indices
col	column indices
val	values
length	length of the given arrays

Definition at line 50 of file SdpVarfixer.c.

Referenced by multiaggrVar(), SCIPsdpVarfixerMergeArrays(), and SCIPsdpVarfixerMergeArraysIntoNew().

SCIP_RETCODE SCIPsdpVarfixerMergeArrays	(	BMS_BLKMEM *	blkmem,
		SCIP_Real	feastol,
		int *	originrow,
		int *	origincol,
		SCIP_Real *	originval,
		int	originlength,
		SCIP_Bool	originsorted,
		SCIP_Real	scalar,
		int *	targetrow,
		int *	targetcol,
		SCIP_Real *	targetval,
		int *	targetlength,
		int	targetmemory
	)

merges two three-tuple-arrays together

The original arrays (which may have multiple entries for the same row and col) will be mulitplied with scalar and then merged into the target arrays (which may not have multiple entries for the same row and col). If there is already an entry for a row/col combination, these two entries will be combined (their values added together), if they cancel each other out the nonzero entry will be removed. If you think of the matrices described by the two arrays, this is a matrix addition (but only working on the nonzeros for efficiency). The target arrays need to be long enough, otherwise targetlength returns the needed amount and a corresponding debug message is thrown.

Parameters

blkmem	block memory
feastol	only values bigger than this are counted as nonzeros
originrow	original row-index-array that is going to be merged, may be NULL if originlength = 0
origincol	original column-index-array that is going to be merged, may be NULL if originlength = 0
originval	original nonzero-values-array that is going to be merged, may be NULL if originlength = 0
originlength	length of the original arrays
originsorted	are the origin arrays already sorted by non-decreasing row and in case of ties col
scalar	scalar that the original nonzero-values will be multiplied with before merging
targetrow	row-index-array the original array will be merged into
targetcol	column-index-array the original array will be merged into
targetval	nonzero-values-array the original array will be merged into
targetlength	length of the target arrays the original arrays will be merged into, this will be updated to the new length after the mergings
targetmemory	amount of memory allocated for targetrow, -col, -val, if this isn't sufficient targetlength will return the needed amount and a corresponding debug message will be thrown

Definition at line 88 of file SdpVarfixer.c.

References SCIPsdpVarfixerSortRowCol().

Referenced by fixAndAggrVars(), and multiaggrVar().

SCIP_RETCODE SCIPsdpVarfixerMergeArraysIntoNew	(	BMS_BLKMEM *	blkmem,
		SCIP_Real	feastol,
		int *	firstrow,
		int *	firstcol,
		SCIP_Real *	firstval,
		int	firstlength,
		int *	secondrow,
		int *	secondcol,
		SCIP_Real *	secondval,
		int	secondlength,
		int *	targetrow,
		int *	targetcol,
		SCIP_Real *	targetval,
		int *	targetlength
	)

merges two three-tuple-arrays together

If there are multiple entries for a row/col combination, these will be combined (their values added together), if they cancel each other out the nonzero entry will be removed. The first arrays are assumed to have unique row/col-combinations, the second arrays may have duplicates of the same row/col-combination. In constrast to MergeArrays, here the combined arrays will be inserted in the new targetarrays, and not overwrite one of the old arrays. targetlength should give the length of the target arrays, if this is not sufficient, the needed length is returned there and a debug message is thrown.

Parameters

blkmem	block memory
feastol	only values bigger than this are counted as nonzeros
firstrow	first row-index-array that is going to be merged, may be NULL if firstlength = 0
firstcol	first column-index-array that is going to be merged, may be NULL if firstlength = 0
firstval	first nonzero-values-array that is going to be merged, may be NULL if firstlength = 0
firstlength	length of the first arrays
secondrow	second row-index-array that is going to be merged, may be NULL if secondlength = 0
secondcol	second column-index-array that is going to be merged, may be NULL if secondlength = 0
secondval	second nonzero-values-array that is going to be merged, may be NULL if secondlength = 0
secondlength	length of the second arrays
targetrow	row-index-array the original arrays will be merged into
targetcol	column-index-array the original arrays will be merged into
targetval	nonzero-values-array the original arrays will be merged into
targetlength	length of the target arrays the original arrays will be merged into, this will be updated to the new length after the mergings

Definition at line 255 of file SdpVarfixer.c.

References SCIPsdpVarfixerSortRowCol().

Referenced by compConstMatAfterFixings().