Line data    Source code

       1             : //------------------------------------------------------------------------------
       2             : // LAGraph_Cached_AT: construct G->AT for a graph
       3             : //------------------------------------------------------------------------------
       4             : 
       5             : // LAGraph, (c) 2019-2022 by The LAGraph Contributors, All Rights Reserved.
       6             : // SPDX-License-Identifier: BSD-2-Clause
       7             : //
       8             : // For additional details (including references to third party source code and
       9             : // other files) see the LICENSE file or contact permission@sei.cmu.edu. See
      10             : // Contributors.txt for a full list of contributors. Created, in part, with
      11             : // funding and support from the U.S. Government (see Acknowledgments.txt file).
      12             : // DM22-0790
      13             : 
      14             : // Contributed by Timothy A. Davis, Texas A&M University
      15             : 
      16             : //------------------------------------------------------------------------------
      17             : 
      18             : #define LG_FREE_ALL GrB_free (&AT) ;
      19             : 
      20             : #include "LG_internal.h"
      21             : 
      22        1279 : int LAGraph_Cached_AT
      23             : (
      24             :     // input/output:
      25             :     LAGraph_Graph G,    // graph for which to compute G->AT
      26             :     char *msg
      27             : )
      28             : {
      29             : 
      30             :     //--------------------------------------------------------------------------
      31             :     // clear msg and check G
      32             :     //--------------------------------------------------------------------------
      33             : 
      34        1279 :     GrB_Matrix AT = NULL ;
      35        1279 :     LG_CLEAR_MSG_AND_BASIC_ASSERT (G, msg) ;
      36        1279 :     GrB_Matrix A = G->A ;
      37             : 
      38        1279 :     if (G->AT != NULL)
      39             :     {
      40             :         // G->AT already computed
      41          42 :         return (GrB_SUCCESS) ;
      42             :     }
      43             : 
      44        1237 :     if (G->kind == LAGraph_ADJACENCY_UNDIRECTED)
      45             :     {
      46             :         // G->AT not needed since A is symmetric (warning only, not an error)
      47          72 :         return (LAGRAPH_CACHE_NOT_NEEDED) ;
      48             :     }
      49             : 
      50             :     //--------------------------------------------------------------------------
      51             :     // G->AT = (G->A)'
      52             :     //--------------------------------------------------------------------------
      53             : 
      54             :     GrB_Index nrows, ncols ;
      55        1165 :     GRB_TRY (GrB_Matrix_nrows (&nrows, A)) ;
      56        1165 :     GRB_TRY (GrB_Matrix_ncols (&ncols, A)) ;
      57             :     GrB_Type atype ;
      58             :     char atype_name [LAGRAPH_MAX_NAME_LEN] ;
      59        1165 :     LG_TRY (LAGraph_Matrix_TypeName (atype_name, A, msg)) ;
      60        1165 :     LG_TRY (LAGraph_TypeFromName (&atype, atype_name, msg)) ;
      61        1165 :     GRB_TRY (GrB_Matrix_new (&AT, atype, ncols, nrows)) ;
      62         848 :     GRB_TRY (GrB_transpose (AT, NULL, NULL, A, NULL)) ;
      63         605 :     G->AT = AT ;
      64             : 
      65         605 :     return (GrB_SUCCESS) ;
      66             : }