diff -Nur qwtplot3d/src/qwt3d_function.cpp qwtplot3d.new//src/qwt3d_function.cpp
--- qwtplot3d/src/qwt3d_function.cpp	2004-06-09 18:57:38.000000000 +0200
+++ qwtplot3d.new//src/qwt3d_function.cpp	2010-12-17 20:28:21.720990823 +0100
@@ -1,5 +1,6 @@
 #include "qwt3d_surfaceplot.h"
 #include "qwt3d_function.h"
+#include <cstdio>
 
 using namespace Qwt3D;