.TH "TESTING/LIN/csbmv.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/LIN/csbmv.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBcsbmv\fP (uplo, n, k, alpha, a, lda, x, incx, beta, y, incy)" .br .RI "\fBCSBMV\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine csbmv (character uplo, integer n, integer k, complex alpha, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) x, integer incx, complex beta, complex, dimension( * ) y, integer incy)" .PP \fBCSBMV\fP .PP \fBPurpose:\fP .RS 4 .PP .nf CSBMV performs the matrix-vector operation y := alpha*A*x + beta*y, where alpha and beta are scalars, x and y are n element vectors and A is an n by n symmetric band matrix, with k super-diagonals\&. .fi .PP .PP .nf UPLO - CHARACTER*1 On entry, UPLO specifies whether the upper or lower triangular part of the band matrix A is being supplied as follows: UPLO = 'U' or 'u' The upper triangular part of A is being supplied\&. UPLO = 'L' or 'l' The lower triangular part of A is being supplied\&. Unchanged on exit\&. N - INTEGER On entry, N specifies the order of the matrix A\&. N must be at least zero\&. Unchanged on exit\&. K - INTEGER On entry, K specifies the number of super-diagonals of the matrix A\&. K must satisfy 0 \&.le\&. K\&. Unchanged on exit\&. ALPHA - COMPLEX On entry, ALPHA specifies the scalar alpha\&. Unchanged on exit\&. A - COMPLEX array, dimension( LDA, N ) Before entry with UPLO = 'U' or 'u', the leading ( k + 1 ) by n part of the array A must contain the upper triangular band part of the symmetric matrix, supplied column by column, with the leading diagonal of the matrix in row ( k + 1 ) of the array, the first super-diagonal starting at position 2 in row k, and so on\&. The top left k by k triangle of the array A is not referenced\&. The following program segment will transfer the upper triangular part of a symmetric band matrix from conventional full matrix storage to band storage: DO 20, J = 1, N M = K + 1 - J DO 10, I = MAX( 1, J - K ), J A( M + I, J ) = matrix( I, J ) 10 CONTINUE 20 CONTINUE Before entry with UPLO = 'L' or 'l', the leading ( k + 1 ) by n part of the array A must contain the lower triangular band part of the symmetric matrix, supplied column by column, with the leading diagonal of the matrix in row 1 of the array, the first sub-diagonal starting at position 1 in row 2, and so on\&. The bottom right k by k triangle of the array A is not referenced\&. The following program segment will transfer the lower triangular part of a symmetric band matrix from conventional full matrix storage to band storage: DO 20, J = 1, N M = 1 - J DO 10, I = J, MIN( N, J + K ) A( M + I, J ) = matrix( I, J ) 10 CONTINUE 20 CONTINUE Unchanged on exit\&. LDA - INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program\&. LDA must be at least ( k + 1 )\&. Unchanged on exit\&. X - COMPLEX array, dimension at least ( 1 + ( N - 1 )*abs( INCX ) )\&. Before entry, the incremented array X must contain the vector x\&. Unchanged on exit\&. INCX - INTEGER On entry, INCX specifies the increment for the elements of X\&. INCX must not be zero\&. Unchanged on exit\&. BETA - COMPLEX On entry, BETA specifies the scalar beta\&. Unchanged on exit\&. Y - COMPLEX array, dimension at least ( 1 + ( N - 1 )*abs( INCY ) )\&. Before entry, the incremented array Y must contain the vector y\&. On exit, Y is overwritten by the updated vector y\&. INCY - INTEGER On entry, INCY specifies the increment for the elements of Y\&. INCY must not be zero\&. Unchanged on exit\&. .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB150\fP of file \fBcsbmv\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.