MacOSX: problem report of nbody_3d.py

[iamyoukou]

On MacOSX(10.11.6), some errors will happen when execute nbody_3d.py.
I fixed them in a not clever way, but it works for me.

Traceback (most recent call last):
 File "nbody_3d.py", line 1, in <module>
   from taichi.dynamics.nbody import NBody
 File "/Users/YJ-work/Desktop/taichi_root/taichi/python/taichi/dynamics/nbody.py", line 6, in <module>
   from taichi.tools.video import VideoManager
 File "/Users/YJ-work/Desktop/taichi_root/taichi/python/taichi/tools/video.py", line 1, in <module>
   from taichi import ndarray_to_array2d
ImportError: cannot import name ndarray_to_array2d

I replaced from taichi import ndarray_to_array2d with from taichi.misc.util import ndarray_to_array2d in taichi.tools.video.

[Errno 2] No such file or directory: '/Users/YJ-work/Desktop/taichi_root//taichi_outputs///task-2017-01-10-21-51-00-r07015'
Simulation time: 0.0
nbody.cpp[201]: node_end = 297117
Time: 0.0983819961548
Segmentation fault: 11

I replaced self.directory = taichi.get_output_path(get_unique_task_id()) with a full path self.directory = '/Users/YJ-work/Desktop/taichi_root/taichi/output/' in taichi.dynamics.nbody

Traceback (most recent call last):
  File "nbody_3d.py", line 6, in <module>
    nbody.step(0.01)
  File "/Users/YJ-work/Desktop/taichi_root/taichi/python/taichi/dynamics/nbody.py", line 49, in step
    img = LDRDisplay(exposure=1, adaptive_exposure=False).process(img)
NameError: global name 'LDRDisplay' is not defined

I added from taichi.visual.post_process import LDRDisplay in taichi.dynamics.nbody.

Traceback (most recent call last):
  File "nbody_3d.py", line 6, in <module>
    nbody.step(0.01)
  File "/Users/YJ-work/Desktop/taichi_root/taichi/python/taichi/dynamics/nbody.py", line 53, in step
    self.video_manager.write_frame(img)
  File "/Users/YJ-work/Desktop/taichi_root/taichi/python/taichi/tools/video.py", line 18, in write_frame
    ndarray_to_array2d(img).write(self.directory + '/%05d.png' % self.frame_counter)
AttributeError: 'NoneType' object has no attribute 'write'

I commented out self.video_manager.write_frame(img) in taichi.dynamics.nbody.

Maybe there is a clever way to fix this problem.

BTW, I got this output (one of those frames)

Is it correct?

[yuanming-hu]

Thanks for letting me know. I think they are fixed in later commits and to fix 2 you may want to execute

mkdir $TAICHI_ROOT_DIR/taichi_outputs

Please just pull and see if everything goes well.

[iamyoukou]

I pull the latest one, and it works well. Thanks : )

[yuanming-hu]

Cool. Thanks :-)