FLASH_Apply_QUD_UT_inc_create_workspace.c File Reference

(r)

Functions
FLA_Error	FLASH_Apply_QUD_UT_inc_create_workspace (FLA_Obj T, FLA_Obj R, FLA_Obj *W)

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Function Documentation

FLA_Error FLASH_Apply_QUD_UT_inc_create_workspace	(	FLA_Obj	T,
		FLA_Obj	R,
		FLA_Obj *	W
	)

References FLA_Abort(), FLA_Obj_datatype(), FLA_Obj_length(), FLA_Obj_width(), FLA_Print_message(), FLASH_Obj_create_ext(), FLASH_Obj_depth(), FLASH_Obj_scalar_length_tl(), and FLASH_Obj_scalar_width_tl().

Referenced by FLASH_UDdate_UT_inc_update_rhs().

{
    FLA_Datatype datatype;
    dim_t        depth;
    dim_t        b_alg;
    dim_t        b_flash;
    dim_t        m, n;

    // Query the depth.
    depth = FLASH_Obj_depth( T );

    // *** The current Apply_QUD_UT_inc algorithm implemented assumes that
    // the matrix has a hierarchical depth of 1. We check for that here
    // because we anticipate that we'll use a more general algorithm in the
    // future, and we don't want to forget to remove the constraint. ***
    if ( depth != 1 )
    {
       FLA_Print_message( "FLASH_Apply_QUD_UT_inc() currently only supports matrices of depth 1",
                          __FILE__, __LINE__ );
       FLA_Abort();
    }

    // Query the datatype of matrix T.
    datatype = FLA_Obj_datatype( T );

    // Inspect the length of a the top-left element of T to get the
    // algorithmic blocksize we'll use throughout the Apply_QUD_UT_inc
    // algorithm.
    b_alg = FLASH_Obj_scalar_length_tl( T );

    // The width of the top-left element gives us the storage blocksize.
    b_flash = FLASH_Obj_scalar_width_tl( T );

    // Determine the element (not scalar) dimensions of the new hierarchical
    // matrix W. By using the element dimensions, we will probably allocate
    // more storage than we actually need (at the bottom and right edge cases)
    // but this is simpler than computing the exact amount and the excess
    // storage is usually small in practice.
    m = FLA_Obj_length( R );
    n = FLA_Obj_width( R );

    // Create hierarchical matrix W, with element dimensions conformal to R,
    // where each block is b_alg-by-b_flash.
    FLASH_Obj_create_ext( datatype, m * b_alg, n * b_flash, 
                          depth, &b_alg, &b_flash, 
                          W );
   
    return FLA_SUCCESS;
}