Annotation of rpl/lapack/blas/zgerc.f, revision 1.8
1.8 ! bertrand 1: *> \brief \b ZGERC
! 2: *
! 3: * =========== DOCUMENTATION ===========
! 4: *
! 5: * Online html documentation available at
! 6: * http://www.netlib.org/lapack/explore-html/
! 7: *
! 8: * Definition:
! 9: * ===========
! 10: *
! 11: * SUBROUTINE ZGERC(M,N,ALPHA,X,INCX,Y,INCY,A,LDA)
! 12: *
! 13: * .. Scalar Arguments ..
! 14: * COMPLEX*16 ALPHA
! 15: * INTEGER INCX,INCY,LDA,M,N
! 16: * ..
! 17: * .. Array Arguments ..
! 18: * COMPLEX*16 A(LDA,*),X(*),Y(*)
! 19: * ..
! 20: *
! 21: *
! 22: *> \par Purpose:
! 23: * =============
! 24: *>
! 25: *> \verbatim
! 26: *>
! 27: *> ZGERC performs the rank 1 operation
! 28: *>
! 29: *> A := alpha*x*y**H + A,
! 30: *>
! 31: *> where alpha is a scalar, x is an m element vector, y is an n element
! 32: *> vector and A is an m by n matrix.
! 33: *> \endverbatim
! 34: *
! 35: * Arguments:
! 36: * ==========
! 37: *
! 38: *> \param[in] M
! 39: *> \verbatim
! 40: *> M is INTEGER
! 41: *> On entry, M specifies the number of rows of the matrix A.
! 42: *> M must be at least zero.
! 43: *> \endverbatim
! 44: *>
! 45: *> \param[in] N
! 46: *> \verbatim
! 47: *> N is INTEGER
! 48: *> On entry, N specifies the number of columns of the matrix A.
! 49: *> N must be at least zero.
! 50: *> \endverbatim
! 51: *>
! 52: *> \param[in] ALPHA
! 53: *> \verbatim
! 54: *> ALPHA is COMPLEX*16
! 55: *> On entry, ALPHA specifies the scalar alpha.
! 56: *> \endverbatim
! 57: *>
! 58: *> \param[in] X
! 59: *> \verbatim
! 60: *> X is COMPLEX*16 array of dimension at least
! 61: *> ( 1 + ( m - 1 )*abs( INCX ) ).
! 62: *> Before entry, the incremented array X must contain the m
! 63: *> element vector x.
! 64: *> \endverbatim
! 65: *>
! 66: *> \param[in] INCX
! 67: *> \verbatim
! 68: *> INCX is INTEGER
! 69: *> On entry, INCX specifies the increment for the elements of
! 70: *> X. INCX must not be zero.
! 71: *> \endverbatim
! 72: *>
! 73: *> \param[in] Y
! 74: *> \verbatim
! 75: *> Y is COMPLEX*16 array of dimension at least
! 76: *> ( 1 + ( n - 1 )*abs( INCY ) ).
! 77: *> Before entry, the incremented array Y must contain the n
! 78: *> element vector y.
! 79: *> \endverbatim
! 80: *>
! 81: *> \param[in] INCY
! 82: *> \verbatim
! 83: *> INCY is INTEGER
! 84: *> On entry, INCY specifies the increment for the elements of
! 85: *> Y. INCY must not be zero.
! 86: *> \endverbatim
! 87: *>
! 88: *> \param[in,out] A
! 89: *> \verbatim
! 90: *> A is COMPLEX*16 array of DIMENSION ( LDA, n ).
! 91: *> Before entry, the leading m by n part of the array A must
! 92: *> contain the matrix of coefficients. On exit, A is
! 93: *> overwritten by the updated matrix.
! 94: *> \endverbatim
! 95: *>
! 96: *> \param[in] LDA
! 97: *> \verbatim
! 98: *> LDA is INTEGER
! 99: *> On entry, LDA specifies the first dimension of A as declared
! 100: *> in the calling (sub) program. LDA must be at least
! 101: *> max( 1, m ).
! 102: *> \endverbatim
! 103: *
! 104: * Authors:
! 105: * ========
! 106: *
! 107: *> \author Univ. of Tennessee
! 108: *> \author Univ. of California Berkeley
! 109: *> \author Univ. of Colorado Denver
! 110: *> \author NAG Ltd.
! 111: *
! 112: *> \date November 2011
! 113: *
! 114: *> \ingroup complex16_blas_level2
! 115: *
! 116: *> \par Further Details:
! 117: * =====================
! 118: *>
! 119: *> \verbatim
! 120: *>
! 121: *> Level 2 Blas routine.
! 122: *>
! 123: *> -- Written on 22-October-1986.
! 124: *> Jack Dongarra, Argonne National Lab.
! 125: *> Jeremy Du Croz, Nag Central Office.
! 126: *> Sven Hammarling, Nag Central Office.
! 127: *> Richard Hanson, Sandia National Labs.
! 128: *> \endverbatim
! 129: *>
! 130: * =====================================================================
1.1 bertrand 131: SUBROUTINE ZGERC(M,N,ALPHA,X,INCX,Y,INCY,A,LDA)
1.8 ! bertrand 132: *
! 133: * -- Reference BLAS level2 routine (version 3.4.0) --
! 134: * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
! 135: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
! 136: * November 2011
! 137: *
1.1 bertrand 138: * .. Scalar Arguments ..
1.8 ! bertrand 139: COMPLEX*16 ALPHA
1.1 bertrand 140: INTEGER INCX,INCY,LDA,M,N
141: * ..
142: * .. Array Arguments ..
1.8 ! bertrand 143: COMPLEX*16 A(LDA,*),X(*),Y(*)
1.1 bertrand 144: * ..
145: *
146: * =====================================================================
147: *
148: * .. Parameters ..
1.8 ! bertrand 149: COMPLEX*16 ZERO
1.1 bertrand 150: PARAMETER (ZERO= (0.0D+0,0.0D+0))
151: * ..
152: * .. Local Scalars ..
1.8 ! bertrand 153: COMPLEX*16 TEMP
1.1 bertrand 154: INTEGER I,INFO,IX,J,JY,KX
155: * ..
156: * .. External Subroutines ..
157: EXTERNAL XERBLA
158: * ..
159: * .. Intrinsic Functions ..
160: INTRINSIC DCONJG,MAX
161: * ..
162: *
163: * Test the input parameters.
164: *
165: INFO = 0
166: IF (M.LT.0) THEN
167: INFO = 1
168: ELSE IF (N.LT.0) THEN
169: INFO = 2
170: ELSE IF (INCX.EQ.0) THEN
171: INFO = 5
172: ELSE IF (INCY.EQ.0) THEN
173: INFO = 7
174: ELSE IF (LDA.LT.MAX(1,M)) THEN
175: INFO = 9
176: END IF
177: IF (INFO.NE.0) THEN
178: CALL XERBLA('ZGERC ',INFO)
179: RETURN
180: END IF
181: *
182: * Quick return if possible.
183: *
184: IF ((M.EQ.0) .OR. (N.EQ.0) .OR. (ALPHA.EQ.ZERO)) RETURN
185: *
186: * Start the operations. In this version the elements of A are
187: * accessed sequentially with one pass through A.
188: *
189: IF (INCY.GT.0) THEN
190: JY = 1
191: ELSE
192: JY = 1 - (N-1)*INCY
193: END IF
194: IF (INCX.EQ.1) THEN
195: DO 20 J = 1,N
196: IF (Y(JY).NE.ZERO) THEN
197: TEMP = ALPHA*DCONJG(Y(JY))
198: DO 10 I = 1,M
199: A(I,J) = A(I,J) + X(I)*TEMP
200: 10 CONTINUE
201: END IF
202: JY = JY + INCY
203: 20 CONTINUE
204: ELSE
205: IF (INCX.GT.0) THEN
206: KX = 1
207: ELSE
208: KX = 1 - (M-1)*INCX
209: END IF
210: DO 40 J = 1,N
211: IF (Y(JY).NE.ZERO) THEN
212: TEMP = ALPHA*DCONJG(Y(JY))
213: IX = KX
214: DO 30 I = 1,M
215: A(I,J) = A(I,J) + X(IX)*TEMP
216: IX = IX + INCX
217: 30 CONTINUE
218: END IF
219: JY = JY + INCY
220: 40 CONTINUE
221: END IF
222: *
223: RETURN
224: *
225: * End of ZGERC .
226: *
227: END
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