Library for f2c (part 2 of 2)

Obtained from: netlib.att.com

1 files changed, 36 insertions, 0 deletions

diff --git a/lib/libF77/z_div.c b/lib/libF77/z_div.c
new file mode 100644
index 0000000..fd53733
--- /dev/null
+++ b/lib/libF77/z_div.c
@@ -0,0 +1,36 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+extern void sig_die();
+VOID z_div(c, a, b) doublecomplex *a, *b, *c;
+#else
+extern void sig_die(char*, int);
+void z_div(doublecomplex *c, doublecomplex *a, doublecomplex *b)
+#endif
+{
+double ratio, den;
+double abr, abi;
+
+if( (abr = b->r) < 0.)
+	abr = - abr;
+if( (abi = b->i) < 0.)
+	abi = - abi;
+if( abr <= abi )
+	{
+	if(abi == 0)
+		sig_die("complex division by zero", 1);
+	ratio = b->r / b->i ;
+	den = b->i * (1 + ratio*ratio);
+	c->r = (a->r*ratio + a->i) / den;
+	c->i = (a->i*ratio - a->r) / den;
+	}
+
+else
+	{
+	ratio = b->i / b->r ;
+	den = b->r * (1 + ratio*ratio);
+	c->r = (a->r + a->i*ratio) / den;
+	c->i = (a->i - a->r*ratio) / den;
+	}
+
+}