Fix bug in graph_draw() with new numpy

8 jobs for master
Status Name Job ID Coverage
  Test
passed job_clang_amd64 #442
amd64

03:05:56

passed job_clang_amd64_nosh #446
amd64

03:08:50

passed job_clang_py2_amd64 #444
amd64

02:56:05

passed job_gcc_386 #439
i386

03:04:21

passed job_gcc_amd64 #441
amd64

02:16:49

passed job_gcc_amd64_nosh #445
amd64

02:23:12

passed job_gcc_py2_386 #440
i386

03:02:38

passed job_gcc_py2_amd64 #443
amd64

02:18:30