1 files changed, 16 insertions, 0 deletions

diff --git a/lib/libF77/c_log.c b/lib/libF77/c_log.c
new file mode 100644
index 000000000000..a77521aee548
--- /dev/null
+++ b/lib/libF77/c_log.c
@@ -0,0 +1,16 @@
+#include "f2c.h"
+
+#ifdef KR_headers
+extern double log(), f__cabs(), atan2();
+VOID c_log(r, z) complex *r, *z;
+#else
+#undef abs
+#include "math.h"
+extern double f__cabs(double, double);
+
+void c_log(complex *r, complex *z)
+#endif
+{
+r->i = atan2(z->i, z->r);
+r->r = log( f__cabs(z->r, z->i) );
+}