1 files changed, 25 insertions, 0 deletions
diff --git a/contrib/libf2c/libF77/z_sqrt.c b/contrib/libf2c/libF77/z_sqrt.c
new file mode 100644
index 0000000..954c2fa
--- /dev/null
+++ b/contrib/libf2c/libF77/z_sqrt.c
@@ -0,0 +1,25 @@
+#include "f2c.h"
+
+#undef abs
+#include "math.h"
+extern double f__cabs (double, double);
+void
+z_sqrt (doublecomplex * r, doublecomplex * z)
+{
+  double mag, zi = z->i, zr = z->r;
+
+  if ((mag = f__cabs (zr, zi)) == 0.)
+    r->r = r->i = 0.;
+  else if (zr > 0)
+    {
+      r->r = sqrt (0.5 * (mag + zr));
+      r->i = zi / r->r / 2;
+    }
+  else
+    {
+      r->i = sqrt (0.5 * (mag - zr));
+      if (zi < 0)
+	r->i = -r->i;
+      r->r = zi / r->i / 2;
+    }
+}