.TH CLARGV 1 "November 2006" " LAPACK auxiliary routine (version 3.1) " " LAPACK auxiliary routine (version 3.1) " .SH NAME CLARGV - a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y .SH SYNOPSIS .TP 19 SUBROUTINE CLARGV( N, X, INCX, Y, INCY, C, INCC ) .TP 19 .ti +4 INTEGER INCC, INCX, INCY, N .TP 19 .ti +4 REAL C( * ) .TP 19 .ti +4 COMPLEX X( * ), Y( * ) .SH PURPOSE CLARGV generates a vector of complex plane rotations with real cosines, determined by elements of the complex vectors x and y. For i = 1,2,...,n .br ( c(i) s(i) ) ( x(i) ) = ( r(i) ) .br ( -conjg(s(i)) c(i) ) ( y(i) ) = ( 0 ) .br where c(i)**2 + ABS(s(i))**2 = 1 .br The following conventions are used (these are the same as in CLARTG, but differ from the BLAS1 routine CROTG): .br If y(i)=0, then c(i)=1 and s(i)=0. .br If x(i)=0, then c(i)=0 and s(i) is chosen so that r(i) is real. .SH ARGUMENTS .TP 8 N (input) INTEGER The number of plane rotations to be generated. .TP 8 X (input/output) COMPLEX array, dimension (1+(N-1)*INCX) On entry, the vector x. On exit, x(i) is overwritten by r(i), for i = 1,...,n. .TP 8 INCX (input) INTEGER The increment between elements of X. INCX > 0. .TP 8 Y (input/output) COMPLEX array, dimension (1+(N-1)*INCY) On entry, the vector y. On exit, the sines of the plane rotations. .TP 8 INCY (input) INTEGER The increment between elements of Y. INCY > 0. .TP 8 C (output) REAL array, dimension (1+(N-1)*INCC) The cosines of the plane rotations. .TP 8 INCC (input) INTEGER The increment between elements of C. INCC > 0. .SH FURTHER DETAILS 6-6-96 - Modified with a new algorithm by W. Kahan and J. Demmel This version has a few statements commented out for thread safety (machine parameters are computed on each entry). 10 feb 03, SJH.