SUBROUTINE CLARTG( F, G, CS, SN, R ) REAL CS COMPLEX F, G, R, SN
CLARTG generates a plane rotation so that [ -SN CS ] [ G ] [ 0 ] This is a faster version of the BLAS1 routine CROTG, except for the following differences: F and G are unchanged on return. If G=0, then CS=1 and SN=0. If F=0 and (G .ne. 0), then CS=0 and SN=1 without doing any floating point operations.
F (input) COMPLEX The first component of vector to be rotated. G (input) COMPLEX The second component of vector to be rotated. CS (output) REAL The cosine of the rotation. SN (output) COMPLEX The sine of the rotation. R (output) COMPLEX The nonzero component of the rotated vector.