sgesum(3S)
SGESUM, DGESUM, CGESUM, ZGESUM - Adds a scalar multiple of a real or complex matrix to a scalar multiple of another real or complex matrix
As shipped in IRIX 6.5.30. Added in IRIX 6.5.15.
NAME SGESUM, DGESUM, CGESUM, ZGESUM - Adds a scalar multiple of a real or complex matrix to a scalar multiple of another real or complex matrix SYNOPSIS Single precision Fortran: CALL SGESUM (trans, m, n, alpha, a, lda, beta, b, ldb) C/C++: #include <scsl_blas.h> void sgesum (char *trans, int m, int n, float alpha, float *a, int lda, float beta, float *b, int ldb); Double precision Fortran: CALL DGESUM (trans, m, n, alpha, a, lda, beta, b, ldb) C/C++: #include <scsl_blas.h> void dgesum (char *trans, int m, int n, double alpha, double *a, int lda, double beta, double *b, int ldb); Single precision complex Fortran: CALL CGESUM (trans, m, n, alpha, a, lda, beta, b, ldb) C/C++: #include <scsl_blas.h> void cgesum (char *trans, int m, int n, scsl_complex *alpha, scsl_complex *a, int lda, scsl_complex *beta, scsl_complex *b, int ldb); C++ STL: #include <complex.h> #include <scsl_blas.h> void cgesum (char *trans, int m, int n, complex<float> *alpha, complex<float> *a, int lda, complex<float> *beta, complex<float> *b, int ldb); Double precision complex Fortran: CALL ZGESUM (trans, m, n, alpha, a, lda, beta, b, ldb) C/C++: #include <scsl_blas.h> void zgesum (char *trans, int m, int n, scsl_zomplex *alpha, scsl_zomplex *a, int lda, scsl_zomplex *beta, scsl_zomplex *b, int ldb); C++ STL: #include <complex.h> #include <scsl_blas.h> void zgesum (char *trans, int m, int n, complex<double> *alpha, complex<double> *a, int lda, complex<double> *beta, complex<double> *b, int ldb); IMPLEMENTATION These routines are part of the SCSL Scientific Library and can be loaded using either the -lscs or the -lscs_mp option. The -lscs_mp option directs the linker to use the multi-processor version of the library. When linking to SCSL with -lscs or -lscs_mp, the default integer size is 4 bytes (32 bits). Another version of SCSL is available in which integers are 8 bytes (64 bits). This version allows the user access to larger memory sizes and helps when porting legacy Cray codes. It can be loaded by using the -lscs_i8 option or the -lscs_i8_mp option. A program may use only one of the two versions; 4-byte integer and 8-byte integer library calls cannot be mixed. The C and C++ prototypes shown above are appropriate for the 4-byte integer version of SCSL. When using the 8-byte integer version, the variables of type int become long long and the <scsl_blas_i8.h> header file should be included. DESCRIPTION SGESUM and DGESUM add two real matrices with optional scaling; CGESUM and ZGESUM add two complex matrices. B <- alpha op(A) + beta B where * op(A) represents A, its transpose AT, or its conjugate transpose AH * op(A) and B are m-by-n matrices * alpha and beta are scalars. beta=0 is a special case, used to copy alpha*op(A) to B. alpha=0 is a special case, used to scale B. These routines have the following arguments: trans Character. (input) Specifies whether the matrix A is transposed. trans = 'N' or 'n': op(A) = A trans = 'T' or 't': op(A) = A T trans = 'C' or 'c': op(A) = AT (SGESUM, DGESUM), or op(A) = AH (CGESUM, ZGESUM) For C/C++, a pointer to this character is passed. m Integer. (input) Specifies the number of rows in matrix op(A) and in matrix B. n Integer. (input) Specifies the number of columns in matrix op(A) and in matrix B. alpha Scalar alpha. (input) SGESUM: Single precision. DGESUM: Double precision. CGESUM: Single precision complex. ZGESUM: Double precision complex. For C/C++, a pointer to this scalar is passed when alpha is complex; otherwise, alpha is passed by value. a Array of dimension (lda,k). (input) SGESUM: Single precision array. DGESUM: Double precision array. CGESUM: Single precision complex array. ZGESUM: Double precision complex array. When trans = 'N' or 'n', k is n; otherwise, it is m. When trans = 'N' or 'n', the leading m-by-n part of the array a contains matrix A. When trans = 'T' or 't' or trans = 'C' or 'c', the leading n-by-m part or the array a contains matrix A, whose transpose or conjugate transpose will be used in the matrix sum. If alpha = 0, a need not be specified on entry. lda Integer. (input) Specifies the first dimension of a as declared in the calling program. When trans = 'N' or 'n', lda >= MAX(1,m); otherwise, lda >= MAX(1,n). beta Scalar beta. (input) SGESUM: Single precision. DGESUM: Double precision. CGESUM: Single precision complex. ZGESUM: Double precision complex. For C/C++, a pointer to this scalar is passed when beta is complex; otherwise, beta is passed by value. b Array of dimension (ldb,n). (input/output) SGESUM: Single precision array. DGESUM: Double precision array. CGESUM: Single precision complex array. ZGESUM: Double precision complex array. On entry, if beta is not equal to 0, the m-by-n matrix b contains B. (If beta = 0, b need not be specifed on entry.) On exit, b is overwritten with the matrix sum (alpha*op(A) + beta*B). ldb Integer. (input) The leading dimension of array b. ldb >= MAX(1,m). NOTES These routines are extensions to the Level 2 BLAS. The following data types are described in this documentation: Term Used Data type Fortran: Array dimensioned n x(n) Array of dimensions (m,n) x(m,n) Character CHARACTER Integer INTEGER (INTEGER*8 for -lscs_i8[_mp]) Single precision REAL Double precision DOUBLE PRECISION Single precision complex COMPLEX Double precision complex DOUBLE COMPLEX C/C++: Array dimensioned n x[n] Array of dimensions (m,n) x[m*n] Character char Integer int (long long for -lscs_i8[_mp]) Single precision float Double precision double Single precision complex scsl_complex Double precision complex scsl_zomplex C++ STL: Array dimensioned n x[n] Array of dimensions (m,n) x[m*n] Character char Integer int (long long for -lscs_i8[_mp]) Single precision float Double precision double Single precision complex complex<float> Double precision complex complex<double> Note that you can explicitly declare multidimensional C/C++ arrays provided that the array dimensions are swapped with respect to the Fortran declaration (e.g., x[n][m] in C/C++ versus x(m,n) in Fortran). To avoid a compiler type mismatch error in C++ (or a compiler warning message in C), however, the array should be cast to a pointer of the appropriate type when passed as an argument to a SCSL routine. EXAMPLES An important use of these routines is to copy an array to another array, in which the second array may be a temporary workspace that has a better data layout than the first array. For example, suppose array A was declared as follows in the main program: REAL A(1024, 1024) The following call to SGESUM copies a 64-by-64 block of A to B: CALL SGESUM ('N', 64, 64 1.0, A(1,1), 1024, 0.0, B(1,1), 80) Similarly, the following call copies a 64-by-64 block of the transpose of A to B: CALL SGESUM ('T', 64, 64, 1.0, A(1,1), 1024, 0.0, B(1,1), 80) SEE ALSO INTRO_SCSL(3S), INTRO_BLAS2(3S), SAXPBY(3S) INTRO_CBLAS(3S) for information about using the C interface to Fortran 77 Basic Linear Algebra Subprograms (legacy BLAS) set forth by the Basic Linear Algebra Subprograms Technical Forum.