*DECK CSSCAL SUBROUTINE CSSCAL (N, SA, CX, INCX) C***BEGIN PROLOGUE CSSCAL C***PURPOSE Scale a complex vector. C***LIBRARY SLATEC (BLAS) C***CATEGORY D1A6 C***TYPE COMPLEX (CSSCAL-C) C***KEYWORDS BLAS, LINEAR ALGEBRA, SCALE, VECTOR C***AUTHOR Lawson, C. L., (JPL) C Hanson, R. J., (SNLA) C Kincaid, D. R., (U. of Texas) C Krogh, F. T., (JPL) C***DESCRIPTION C C B L A S Subprogram C Description of Parameters C C --Input-- C N number of elements in input vector(s) C SA single precision scale factor C CX complex vector with N elements C INCX storage spacing between elements of CX C C --Output-- C CX scaled result (unchanged if N .LE. 0) C C Replace complex CX by (single precision SA) * (complex CX) C For I = 0 to N-1, replace CX(IX+I*INCX) with SA * CX(IX+I*INCX), C where IX = 1 if INCX .GE. 0, else IX = 1+(1-N)*INCX. C C***REFERENCES C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T. C Krogh, Basic linear algebra subprograms for Fortran C usage, Algorithm No. 539, Transactions on Mathematical C Software 5, 3 (September 1979), pp. 308-323. C***ROUTINES CALLED (NONE) C***REVISION HISTORY (YYMMDD) C 791001 DATE WRITTEN C 890831 Modified array declarations. (WRB) C 890831 REVISION DATE from Version 3.2 C 891214 Prologue converted to Version 4.0 format. (BAB) C 900821 Modified to correct problem with a negative increment. C (WRB) C 920501 Reformatted the REFERENCES section. (WRB) C***END PROLOGUE CSSCAL COMPLEX CX(*) REAL SA INTEGER I, INCX, IX, N C***FIRST EXECUTABLE STATEMENT CSSCAL IF (N .LE. 0) RETURN C IF (INCX .EQ. 1) GOTO 20 C C Code for increment not equal to 1. C IX = 1 IF (INCX .LT. 0) IX = (-N+1)*INCX + 1 DO 10 I = 1,N CX(IX) = SA*CX(IX) IX = IX + INCX 10 CONTINUE RETURN C C Code for increment equal to 1. C 20 DO 30 I = 1,N CX(I) = SA*CX(I) 30 CONTINUE RETURN END