|
|
 |
|
|
MAN page from openSUSE Leap 42 blas-man-3.5.0-9.1.noarch.rpm
cher2k.fSection: LAPACK (3) Updated: Fri Nov 4 2016 Index NAMEcher2k.f - SYNOPSIS Functions/Subroutines
subroutine CHER2K (UPLO, TRANS, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
CHER2K
Function/Subroutine Documentation subroutine CHER2K (character UPLO, character TRANS, integer N, integer K, complex ALPHA, complex, dimension(lda,*) A, integer LDA, complex, dimension(ldb,*) B, integer LDB, real BETA, complex, dimension(ldc,*) C, integer LDC)CHER2K Purpose: CHER2K performs one of the hermitian rank 2k operations C := alpha*A*B**H + conjg( alpha )*B*A**H + beta*C, or C := alpha*A**H*B + conjg( alpha )*B**H*A + beta*C, where alpha and beta are scalars with beta real, C is an n by n hermitian matrix and A and B are n by k matrices in the first case and k by n matrices in the second case.
Parameters: - UPLO
UPLO is CHARACTER*1 On entry, UPLO specifies whether the upper or lower triangular part of the array C is to be referenced as follows: UPLO = 'U' or 'u' Only the upper triangular part of C is to be referenced. UPLO = 'L' or 'l' Only the lower triangular part of C is to be referenced.
TRANS
TRANS is CHARACTER*1 On entry, TRANS specifies the operation to be performed as follows: TRANS = 'N' or 'n' C := alpha*A*B**H + conjg( alpha )*B*A**H + beta*C. TRANS = 'C' or 'c' C := alpha*A**H*B + conjg( alpha )*B**H*A + beta*C.
N
N is INTEGER On entry, N specifies the order of the matrix C. N must be at least zero.
K
K is INTEGER On entry with TRANS = 'N' or 'n', K specifies the number of columns of the matrices A and B, and on entry with TRANS = 'C' or 'c', K specifies the number of rows of the matrices A and B. K must be at least zero.
ALPHA
ALPHA is COMPLEX On entry, ALPHA specifies the scalar alpha.
A
A is COMPLEX array of DIMENSION ( LDA, ka ), where ka is k when TRANS = 'N' or 'n', and is n otherwise. Before entry with TRANS = 'N' or 'n', the leading n by k part of the array A must contain the matrix A, otherwise the leading k by n part of the array A must contain the matrix A.
LDA
LDA is INTEGER On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When TRANS = 'N' or 'n' then LDA must be at least max( 1, n ), otherwise LDA must be at least max( 1, k ).
B
B is COMPLEX array of DIMENSION ( LDB, kb ), where kb is k when TRANS = 'N' or 'n', and is n otherwise. Before entry with TRANS = 'N' or 'n', the leading n by k part of the array B must contain the matrix B, otherwise the leading k by n part of the array B must contain the matrix B.
LDB
LDB is INTEGER On entry, LDB specifies the first dimension of B as declared in the calling (sub) program. When TRANS = 'N' or 'n' then LDB must be at least max( 1, n ), otherwise LDB must be at least max( 1, k ).
BETA
BETA is REAL On entry, BETA specifies the scalar beta.
C
C is COMPLEX array of DIMENSION ( LDC, n ). Before entry with UPLO = 'U' or 'u', the leading n by n upper triangular part of the array C must contain the upper triangular part of the hermitian matrix and the strictly lower triangular part of C is not referenced. On exit, the upper triangular part of the array C is overwritten by the upper triangular part of the updated matrix. Before entry with UPLO = 'L' or 'l', the leading n by n lower triangular part of the array C must contain the lower triangular part of the hermitian matrix and the strictly upper triangular part of C is not referenced. On exit, the lower triangular part of the array C is overwritten by the lower triangular part of the updated matrix. Note that the imaginary parts of the diagonal elements need not be set, they are assumed to be zero, and on exit they are set to zero.
LDC
LDC is INTEGER On entry, LDC specifies the first dimension of C as declared in the calling (sub) program. LDC must be at least max( 1, n ).
Author: - Univ. of Tennessee
Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.
Date: - November 2011
Further Details: Level 3 Blas routine. -- Written on 8-February-1989. Jack Dongarra, Argonne National Laboratory. Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical Algorithms Group Ltd. Sven Hammarling, Numerical Algorithms Group Ltd. -- Modified 8-Nov-93 to set C(J,J) to REAL( C(J,J) ) when BETA = 1. Ed Anderson, Cray Research Inc.
Definition at line 199 of file cher2k.f. 199 *200 * -- Reference BLAS level3 routine (version 3.4.0) --201 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --202 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--203 * November 2011204 *205 * .. Scalar Arguments ..206 COMPLEX alpha207 REAL beta208 INTEGER k,lda,ldb,ldc,n209 CHARACTER trans,uplo210 * ..211 * .. Array Arguments ..212 COMPLEX a(lda,*),b(ldb,*),c(ldc,*)213 * ..214 *215 * =====================================================================216 *217 * .. External Functions ..218 LOGICAL lsame219 EXTERNAL lsame220 * ..221 * .. External Subroutines ..222 EXTERNAL xerbla223 * ..224 * .. Intrinsic Functions ..225 INTRINSIC conjg,max,real226 * ..227 * .. Local Scalars ..228 COMPLEX temp1,temp2229 INTEGER i,info,j,l,nrowa230 LOGICAL upper231 * ..232 * .. Parameters ..233 REAL one234 parameter(one=1.0e+0)235 COMPLEX zero236 parameter(zero= (0.0e+0,0.0e+0))237 * ..238 *239 * Test the input parameters.240 *241 IF (lsame(trans,'N')) THEN242 nrowa = n243 ELSE244 nrowa = k245 END IF246 upper = lsame(uplo,'U')247 *248 info = 0249 IF ((.NOT.upper) .AND. (.NOT.lsame(uplo,'L'))) THEN250 info = 1251 ELSE IF ((.NOT.lsame(trans,'N')) .AND.252 + (.NOT.lsame(trans,'C'))) THEN253 info = 2254 ELSE IF (n.LT.0) THEN255 info = 3256 ELSE IF (k.LT.0) THEN257 info = 4258 ELSE IF (lda.LT.max(1,nrowa)) THEN259 info = 7260 ELSE IF (ldb.LT.max(1,nrowa)) THEN261 info = 9262 ELSE IF (ldc.LT.max(1,n)) THEN263 info = 12264 END IF265 IF (info.NE.0) THEN266 CALL xerbla('CHER2K',info)267 RETURN268 END IF269 *270 * Quick return if possible.271 *272 IF ((n.EQ.0) .OR. (((alpha.EQ.zero).OR.273 + (k.EQ.0)).AND. (beta.EQ.one))) RETURN274 *275 * And when alpha.eq.zero.276 *277 IF (alpha.EQ.zero) THEN278 IF (upper) THEN279 IF (beta.EQ.REAL(zero)) then280 DO 20 j = 1,n281 DO 10 i = 1,j282 c(i,j) = zero283 10 CONTINUE284 20 CONTINUE285 ELSE286 DO 40 j = 1,n287 DO 30 i = 1,j - 1288 c(i,j) = beta*c(i,j)289 30 CONTINUE290 c(j,j) = beta*REAL(c(j,j))291 40 CONTINUE292 END IF293 ELSE294 IF (beta.EQ.REAL(zero)) then295 DO 60 j = 1,n296 DO 50 i = j,n297 c(i,j) = zero298 50 CONTINUE299 60 CONTINUE300 ELSE301 DO 80 j = 1,n302 c(j,j) = beta*REAL(c(j,j))303 DO 70 i = j + 1,n304 c(i,j) = beta*c(i,j)305 70 CONTINUE306 80 CONTINUE307 END IF308 END IF309 RETURN310 END IF311 *312 * Start the operations.313 *314 IF (lsame(trans,'N')) THEN315 *316 * Form C := alpha*A*B**H + conjg( alpha )*B*A**H +317 * C.318 *319 IF (upper) THEN320 DO 130 j = 1,n321 IF (beta.EQ.REAL(zero)) then322 DO 90 i = 1,j323 c(i,j) = zero324 90 CONTINUE325 ELSE IF (beta.NE.one) THEN326 DO 100 i = 1,j - 1327 c(i,j) = beta*c(i,j)328 100 CONTINUE329 c(j,j) = beta*REAL(c(j,j))330 ELSE331 c(j,j) = REAL(c(j,j))332 END IF333 DO 120 l = 1,k334 IF ((a(j,l).NE.zero) .OR. (b(j,l).NE.zero)) THEN335 temp1 = alpha*conjg(b(j,l))336 temp2 = conjg(alpha*a(j,l))337 DO 110 i = 1,j - 1338 c(i,j) = c(i,j) + a(i,l)*temp1 +339 + b(i,l)*temp2340 110 CONTINUE341 c(j,j) = REAL(C(J,J)) +342 + REAL(a(j,l)*temp1+b(j,l)*temp2)343 END IF344 120 CONTINUE345 130 CONTINUE346 ELSE347 DO 180 j = 1,n348 IF (beta.EQ.REAL(zero)) then349 DO 140 i = j,n350 c(i,j) = zero351 140 CONTINUE352 ELSE IF (beta.NE.one) THEN353 DO 150 i = j + 1,n354 c(i,j) = beta*c(i,j)355 150 CONTINUE356 c(j,j) = beta*REAL(c(j,j))357 ELSE358 c(j,j) = REAL(c(j,j))359 END IF360 DO 170 l = 1,k361 IF ((a(j,l).NE.zero) .OR. (b(j,l).NE.zero)) THEN362 temp1 = alpha*conjg(b(j,l))363 temp2 = conjg(alpha*a(j,l))364 DO 160 i = j + 1,n365 c(i,j) = c(i,j) + a(i,l)*temp1 +366 + b(i,l)*temp2367 160 CONTINUE368 c(j,j) = REAL(C(J,J)) +369 + REAL(a(j,l)*temp1+b(j,l)*temp2)370 END IF371 170 CONTINUE372 180 CONTINUE373 END IF374 ELSE375 *376 * Form C := alpha*A**H*B + conjg( alpha )*B**H*A +377 * C.378 *379 IF (upper) THEN380 DO 210 j = 1,n381 DO 200 i = 1,j382 temp1 = zero383 temp2 = zero384 DO 190 l = 1,k385 temp1 = temp1 + conjg(a(l,i))*b(l,j)386 temp2 = temp2 + conjg(b(l,i))*a(l,j)387 190 CONTINUE388 IF (i.EQ.j) THEN389 IF (beta.EQ.REAL(zero)) then390 c(j,j) = REAL(alpha*temp1+391 + conjg(alpha)*temp2)392 ELSE393 c(j,j) = beta*REAL(C(J,J)) +394 + REAL(alpha*temp1+395 + conjg(alpha)*temp2)396 END IF397 ELSE398 IF (beta.EQ.REAL(zero)) then399 c(i,j) = alpha*temp1 + conjg(alpha)*temp2400 ELSE401 c(i,j) = beta*c(i,j) + alpha*temp1 +402 + conjg(alpha)*temp2403 END IF404 END IF405 200 CONTINUE406 210 CONTINUE407 ELSE408 DO 240 j = 1,n409 DO 230 i = j,n410 temp1 = zero411 temp2 = zero412 DO 220 l = 1,k413 temp1 = temp1 + conjg(a(l,i))*b(l,j)414 temp2 = temp2 + conjg(b(l,i))*a(l,j)415 220 CONTINUE416 IF (i.EQ.j) THEN417 IF (beta.EQ.REAL(zero)) then418 c(j,j) = REAL(alpha*temp1+419 + conjg(alpha)*temp2)420 ELSE421 c(j,j) = beta*REAL(C(J,J)) +422 + REAL(alpha*temp1+423 + conjg(alpha)*temp2)424 END IF425 ELSE426 IF (beta.EQ.REAL(zero)) then427 c(i,j) = alpha*temp1 + conjg(alpha)*temp2428 ELSE429 c(i,j) = beta*c(i,j) + alpha*temp1 +430 + conjg(alpha)*temp2431 END IF432 END IF433 230 CONTINUE434 240 CONTINUE435 END IF436 END IF437 *438 RETURN439 *440 * End of CHER2K.441 * AuthorGenerated automatically by Doxygen for LAPACK from the source code.
Index- NAME
- SYNOPSIS
- Functions/Subroutines
- Function/Subroutine Documentation
- subroutine CHER2K (character UPLO, character TRANS, integer N, integer K, complex ALPHA, complex, dimension(lda,*) A, integer LDA, complex, dimension(ldb,*) B, integer LDB, real BETA, complex, dimension(ldc,*) C, integer LDC)
- Author
This document was created byman2html,using the manual pages. |
|
|
