00001 /* dladiv.f -- translated by f2c (version 20061008). 00002 You must link the resulting object file with libf2c: 00003 on Microsoft Windows system, link with libf2c.lib; 00004 on Linux or Unix systems, link with .../path/to/libf2c.a -lm 00005 or, if you install libf2c.a in a standard place, with -lf2c -lm 00006 -- in that order, at the end of the command line, as in 00007 cc *.o -lf2c -lm 00008 Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., 00009 00010 http://www.netlib.org/f2c/libf2c.zip 00011 */ 00012 00013 #include "f2c.h" 00014 #include "blaswrap.h" 00015 00016 /* Subroutine */ int dladiv_(doublereal *a, doublereal *b, doublereal *c__, 00017 doublereal *d__, doublereal *p, doublereal *q) 00018 { 00019 doublereal e, f; 00020 00021 00022 /* -- LAPACK auxiliary routine (version 3.2) -- */ 00023 /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ 00024 /* November 2006 */ 00025 00026 /* .. Scalar Arguments .. */ 00027 /* .. */ 00028 00029 /* Purpose */ 00030 /* ======= */ 00031 00032 /* DLADIV performs complex division in real arithmetic */ 00033 00034 /* a + i*b */ 00035 /* p + i*q = --------- */ 00036 /* c + i*d */ 00037 00038 /* The algorithm is due to Robert L. Smith and can be found */ 00039 /* in D. Knuth, The art of Computer Programming, Vol.2, p.195 */ 00040 00041 /* Arguments */ 00042 /* ========= */ 00043 00044 /* A (input) DOUBLE PRECISION */ 00045 /* B (input) DOUBLE PRECISION */ 00046 /* C (input) DOUBLE PRECISION */ 00047 /* D (input) DOUBLE PRECISION */ 00048 /* The scalars a, b, c, and d in the above expression. */ 00049 00050 /* P (output) DOUBLE PRECISION */ 00051 /* Q (output) DOUBLE PRECISION */ 00052 /* The scalars p and q in the above expression. */ 00053 00054 /* ===================================================================== */ 00055 00056 /* .. Local Scalars .. */ 00057 /* .. */ 00058 /* .. Intrinsic Functions .. */ 00059 /* .. */ 00060 /* .. Executable Statements .. */ 00061 00062 if (abs(*d__) < abs(*c__)) { 00063 e = *d__ / *c__; 00064 f = *c__ + *d__ * e; 00065 *p = (*a + *b * e) / f; 00066 *q = (*b - *a * e) / f; 00067 } else { 00068 e = *c__ / *d__; 00069 f = *d__ + *c__ * e; 00070 *p = (*b + *a * e) / f; 00071 *q = (-(*a) + *b * e) / f; 00072 } 00073 00074 return 0; 00075 00076 /* End of DLADIV */ 00077 00078 } /* dladiv_ */