#include "blaswrap.h" #include "f2c.h" /* Subroutine */ int dladiv_(doublereal *a, doublereal *b, doublereal *c__, doublereal *d__, doublereal *p, doublereal *q) { /* -- LAPACK auxiliary routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 Purpose ======= DLADIV performs complex division in real arithmetic a + i*b p + i*q = --------- c + i*d The algorithm is due to Robert L. Smith and can be found in D. Knuth, The art of Computer Programming, Vol.2, p.195 Arguments ========= A (input) DOUBLE PRECISION B (input) DOUBLE PRECISION C (input) DOUBLE PRECISION D (input) DOUBLE PRECISION The scalars a, b, c, and d in the above expression. P (output) DOUBLE PRECISION Q (output) DOUBLE PRECISION The scalars p and q in the above expression. ===================================================================== */ static doublereal e, f; if (abs(*d__) < abs(*c__)) { e = *d__ / *c__; f = *c__ + *d__ * e; *p = (*a + *b * e) / f; *q = (*b - *a * e) / f; } else { e = *c__ / *d__; f = *d__ + *c__ * e; *p = (*b + *a * e) / f; *q = (-(*a) + *b * e) / f; } return 0; /* End of DLADIV */ } /* dladiv_ */