diff -ur qwtplot3d-orig/include/qwt3d_function.h qwtplot3d/include/qwt3d_function.h
--- qwtplot3d-orig/include/qwt3d_function.h	2009-07-25 18:18:58.000000000 -0400
+++ qwtplot3d/include/qwt3d_function.h	2009-07-25 18:19:19.000000000 -0400
@@ -2,6 +2,7 @@
 #define qwt3d_function_h__2004_03_05_13_51_begin_guarded_code
 
 #include "qwt3d_gridmapping.h"
+#include <cstdio>
 
 namespace Qwt3D
 {
Only in qwtplot3d/tmp: qwt3d_function.o