[yt-users] only_on_root

[Christine Simpson]

Hi,

I'm trying to run a script with parallel yt that does some non-yt io.
I'm a little confused about how to use only_on_root.

Here is a test script I've tried:

from yt.mods import * 
from yt.visualization.api import PlotCollection

import matplotlib.colorbar as cb

path =
"/scratch/01112/tg803911/halo88_therm_feed_3.7e-6_LW_RadiationShield_lmax12/DD0010/"
fn = "output_0010"
pf = load(path+fn)
pc = PlotCollection(pf)
pc.add_projection("Density",0)
pc.set_width(20,'kpc')
pc.save(fn)

filename = 'hello_world'

file = only_on_root(open(filename,'w'))
only_on_root(file.write("hello_world \n"))
only_on_root(file.close())

Pasted below is the error.  I'm uncertain about the syntax of
only_on_root.  Do I just wrap it around normal commands?  Also, it seems
that the write command is trying to execute on all the processors.  That
shouldn't be happening, right?

P007 yt : [INFO     ] 2011-11-22 09:50:20,558 Saved
output_0010_Projection_x_Density.png
P008 yt : [INFO     ] 2011-11-22 09:50:20,558 Saved
output_0010_Projection_x_Density.png
P009 yt : [INFO     ] 2011-11-22 09:50:20,560 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
  File "test_parallel_yt.py", line 19, in <module>
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
    only_on_root(file.write("hello_world \n"))
AttributeError    : only_on_root(file.write("hello_world \n"))
'NoneType' object has no attribute 'write'
P010 yt : [INFO     ] 2011-11-22 09:50:20,561 Saved
output_0010_Projection_x_Density.png
AttributeErrorP011 yt : [INFO     ] 2011-11-22 09:50:20,561 Saved
output_0010_Projection_x_Density.png
: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
Traceback (most recent call last):
AttributeError:   File "test_parallel_yt.py", line 19, in <module>
'NoneType' object has no attribute 'write'
P005 yt : [INFO     ] 2011-11-22 09:50:20,562 Saved
output_0010_Projection_x_Density.png
P004 yt : [INFO     ] 2011-11-22 09:50:20,562 Saved
output_0010_Projection_x_Density.png
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P002 yt : [INFO     ] 2011-11-22 09:50:20,583 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P001 yt : [INFO     ] 2011-11-22 09:50:20,589 Saved
output_0010_Projection_x_Density.png
P003 yt : [INFO     ] 2011-11-22 09:50:20,589 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P013 yt : [INFO     ] 2011-11-22 09:50:20,593 Saved
output_0010_Projection_x_Density.png
P014 yt : [INFO     ] 2011-11-22 09:50:20,593 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P012 yt : [INFO     ] 2011-11-22 09:50:20,596 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P015 yt : [INFO     ] 2011-11-22 09:50:20,599 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 19, in <module>
    only_on_root(file.write("hello_world \n"))
AttributeError: 'NoneType' object has no attribute 'write'
P000 yt : [INFO     ] 2011-11-22 09:50:21,410 Saved
output_0010_Projection_x_Density.png
Traceback (most recent call last):
  File "test_parallel_yt.py", line 18, in <module>
    file = only_on_root(open(filename,'w'))
  File
"/share/home/01112/tg803911/yt_17May2011/yt-x86_64/src/yt-hg/yt/funcs.py", line 357, in only_on_root
    return func(*args, **kwargs)
TypeError: 'file' object is not callable
mpispawn.c:303 Unexpected exit status

Child exited abnormally!
Killing remote processes...DONE