Re: [O] Output result of source block to a file

[John Kitchin]

you probably figured out the "import io" and "f = io..." line are not
necessary here.

I couldn't figure out a reasonable way to use :results graphics link
that didn't result in repeating the filename more than desired. These
also both work, but seem to both require repeating the filename twice.

#+BEGIN_SRC python :results graphics link :var fname="test.png" :file "test.png"
import matplotlib.pyplot as plt

plt.plot([1, 2, 3, 1])
plt.savefig(fname)
#+END_SRC

#+BEGIN_SRC python :results graphics link :file "test.png"
import matplotlib.pyplot as plt

plt.plot([1, 2, 3])
plt.savefig("test.png")
#+END_SRC

Something like this should work, but there seem to be some extra bytes
getting put in the png file from the decoding, and latin-1 is the only
one I can get to work. If anyone knows how to get this to work, I am
interested in seeing it!

#+BEGIN_SRC python :results value :file "io.png"
import matplotlib.pyplot as plt
import io
buf = io.BytesIO()

plt.plot([1, 2, 3])
plt.savefig(buf, format='png')

s = buf.getvalue()
return s.decode('latin-1')
#+END_SRC


In general though, all of these are much more work than using
ob-ipython, which just puts images in the buffer for you.

Roger Mason <address@hidden> writes:

> Hello John,
>
> John Kitchin <address@hidden> writes:
>
>> I think you can use something like this:
>>
>> #+BEGIN_SRC python :results output file :var fname="test.png"
>> import matplotlib.pyplot as plt
>> import io
>>
>> f = io.StringIO()
>> plt.plot([1, 2, 3, 17])
>> plt.savefig(fname)
>> print(fname, end='')
>> #+END_SRC
>>
>> It is in Python3.
>
> Thank you.  That works.
>
> Best wishes,
> Roger


--
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu