From a3067c572a049f0f707a404a0fe2c66121b77f0e Mon Sep 17 00:00:00 2001
From: cgohlke <cgohlke@uci.edu>
Date: Mon, 10 Mar 2014 20:56:27 -0700
Subject: [PATCH] Define M_PI (not part of C89)

---
 skimage/exposure/unwrap_2d_ljmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/skimage/exposure/unwrap_2d_ljmu.c b/skimage/exposure/unwrap_2d_ljmu.c
index 6be7966a..0b633268 100644
--- a/skimage/exposure/unwrap_2d_ljmu.c
+++ b/skimage/exposure/unwrap_2d_ljmu.c
@@ -19,6 +19,10 @@
 #include <string.h>
 #include <math.h>
 
+#ifndef M_PI
+#define M_PI 3.1415926535897932384626433832795
+#endif
+
 #define PI M_PI
 #define TWOPI (2 * M_PI)