1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
|
//------------------------------------------------------------------------------
// GrB_Matrix_exportHint: determine sizes of arrays for GrB_Matrix_export
//------------------------------------------------------------------------------
// SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2022, All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//------------------------------------------------------------------------------
#include "GB_transpose.h"
#define GB_FREE_ALL ;
GrB_Info GrB_Matrix_exportHint // suggest the best export format
(
GrB_Format *format, // export format
GrB_Matrix A // matrix to export
)
{
//--------------------------------------------------------------------------
// check inputs
//--------------------------------------------------------------------------
GB_WHERE1 ("GrB_Matrix_exportHint (&format, A)") ;
GB_BURBLE_START ("GrB_Matrix_exportHint") ;
GB_RETURN_IF_NULL (format) ;
GB_RETURN_IF_NULL_OR_FAULTY (A) ;
// finish any pending work since this can change the sparsity of A
GB_MATRIX_WAIT (A) ;
int sparsity = GB_sparsity (A) ;
bool is_csc = A->is_csc ;
//--------------------------------------------------------------------------
// determine format that requires the least amount of modification
//--------------------------------------------------------------------------
switch (sparsity)
{
default:
case GxB_SPARSE :
// CSR and CSC formats are supported by GraphBLAS, so if the matrix
// is sparse by-row or sparse by-column, then suggest CSR or CSC.
// The matrix can be exported with no change at all.
case GxB_BITMAP :
// Bitmap is not supported as a GrB_Format. It cannot be exported
// as full, in general, so select CSR or CSC.
(*format) = is_csc ? GrB_CSC_FORMAT : GrB_CSR_FORMAT ;
break ;
case GxB_HYPERSPARSE :
// Hypersparse is not supported as a GrB_Format. Expanding a huge
// hypersparse matrix to sparse can be costly, so suggest COO.
(*format) = GrB_COO_FORMAT ;
break ;
case GxB_FULL :
// Full is not supported by GraphBLAS
(*format) = is_csc ? GrB_CSC_FORMAT : GrB_CSR_FORMAT ;
// if full was supported by GraphBLAS;
// (*format) = is_csc ? GrB_DENSE_COL_FORMAT : GrB_DENSE_ROW_FORMAT ;
break ;
}
GB_BURBLE_END ;
#pragma omp flush
return (GrB_SUCCESS) ;
}
|
