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Merge pull request #2194 from minrk/clean_nan...
Merge pull request #2194 from minrk/clean_nan Clean nan/inf in json_clean. The floating point values NaN and Infinity are not part of the JSON specification and causes some parsers to throw errors. Since our usage is only for things like the display of function defaults, we can use a basic string representation ('NaN', 'inf', etc) instead.

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octavemagic.py
364 lines | 9.7 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""
===========
octavemagic
===========
Magics for interacting with Octave via oct2py.
.. note::
The ``oct2py`` module needs to be installed separately and
can be obtained using ``easy_install`` or ``pip``.
Usage
=====
``%octave``
{OCTAVE_DOC}
``%octave_push``
{OCTAVE_PUSH_DOC}
``%octave_pull``
{OCTAVE_PULL_DOC}
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2012 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
import tempfile
from glob import glob
from shutil import rmtree
import numpy as np
import oct2py
from xml.dom import minidom
from IPython.core.displaypub import publish_display_data
from IPython.core.magic import (Magics, magics_class, line_magic,
line_cell_magic)
from IPython.testing.skipdoctest import skip_doctest
from IPython.core.magic_arguments import (
argument, magic_arguments, parse_argstring
)
from IPython.utils.py3compat import unicode_to_str
class OctaveMagicError(oct2py.Oct2PyError):
pass
_mimetypes = {'png' : 'image/png',
'svg' : 'image/svg+xml',
'jpg' : 'image/jpeg',
'jpeg': 'image/jpeg'}
@magics_class
class OctaveMagics(Magics):
"""A set of magics useful for interactive work with Octave via oct2py.
"""
def __init__(self, shell):
"""
Parameters
----------
shell : IPython shell
"""
super(OctaveMagics, self).__init__(shell)
self._oct = oct2py.Oct2Py()
self._plot_format = 'png'
# Allow publish_display_data to be overridden for
# testing purposes.
self._publish_display_data = publish_display_data
def _fix_gnuplot_svg_size(self, image, size=None):
"""
GnuPlot SVGs do not have height/width attributes. Set
these to be the same as the viewBox, so that the browser
scales the image correctly.
Parameters
----------
image : str
SVG data.
size : tuple of int
Image width, height.
"""
(svg,) = minidom.parseString(image).getElementsByTagName('svg')
viewbox = svg.getAttribute('viewBox').split(' ')
if size is not None:
width, height = size
else:
width, height = viewbox[2:]
svg.setAttribute('width', '%dpx' % width)
svg.setAttribute('height', '%dpx' % height)
return svg.toxml()
@skip_doctest
@line_magic
def octave_push(self, line):
'''
Line-level magic that pushes a variable to Octave.
`line` should be made up of whitespace separated variable names in the
IPython namespace::
In [7]: import numpy as np
In [8]: X = np.arange(5)
In [9]: X.mean()
Out[9]: 2.0
In [10]: %octave_push X
In [11]: %octave mean(X)
Out[11]: 2.0
'''
inputs = line.split(' ')
for input in inputs:
input = unicode_to_str(input)
self._oct.put(input, self.shell.user_ns[input])
@skip_doctest
@line_magic
def octave_pull(self, line):
'''
Line-level magic that pulls a variable from Octave.
In [18]: _ = %octave x = [1 2; 3 4]; y = 'hello'
In [19]: %octave_pull x y
In [20]: x
Out[20]:
array([[ 1., 2.],
[ 3., 4.]])
In [21]: y
Out[21]: 'hello'
'''
outputs = line.split(' ')
for output in outputs:
output = unicode_to_str(output)
self.shell.push({output: self._oct.get(output)})
@skip_doctest
@magic_arguments()
@argument(
'-i', '--input', action='append',
help='Names of input variables to be pushed to Octave. Multiple names '
'can be passed, separated by commas with no whitespace.'
)
@argument(
'-o', '--output', action='append',
help='Names of variables to be pulled from Octave after executing cell '
'body. Multiple names can be passed, separated by commas with no '
'whitespace.'
)
@argument(
'-s', '--size', action='store',
help='Pixel size of plots, "width,height". Default is "-s 400,250".'
)
@argument(
'-f', '--format', action='store',
help='Plot format (png, svg or jpg).'
)
@argument(
'code',
nargs='*',
)
@line_cell_magic
def octave(self, line, cell=None):
'''
Execute code in Octave, and pull some of the results back into the
Python namespace.
In [9]: %octave X = [1 2; 3 4]; mean(X)
Out[9]: array([[ 2., 3.]])
As a cell, this will run a block of Octave code, without returning any
value::
In [10]: %%octave
....: p = [-2, -1, 0, 1, 2]
....: polyout(p, 'x')
-2*x^4 - 1*x^3 + 0*x^2 + 1*x^1 + 2
In the notebook, plots are published as the output of the cell, e.g.
%octave plot([1 2 3], [4 5 6])
will create a line plot.
Objects can be passed back and forth between Octave and IPython via the
-i and -o flags in line::
In [14]: Z = np.array([1, 4, 5, 10])
In [15]: %octave -i Z mean(Z)
Out[15]: array([ 5.])
In [16]: %octave -o W W = Z * mean(Z)
Out[16]: array([ 5., 20., 25., 50.])
In [17]: W
Out[17]: array([ 5., 20., 25., 50.])
The size and format of output plots can be specified::
In [18]: %%octave -s 600,800 -f svg
...: plot([1, 2, 3]);
'''
args = parse_argstring(self.octave, line)
# arguments 'code' in line are prepended to the cell lines
if cell is None:
code = ''
return_output = True
line_mode = True
else:
code = cell
return_output = False
line_mode = False
code = ' '.join(args.code) + code
if args.input:
for input in ','.join(args.input).split(','):
input = unicode_to_str(input)
self._oct.put(input, self.shell.user_ns[input])
# generate plots in a temporary directory
plot_dir = tempfile.mkdtemp()
if args.size is not None:
size = args.size
else:
size = '400,240'
if args.format is not None:
plot_format = args.format
else:
plot_format = 'png'
pre_call = '''
global __ipy_figures = [];
page_screen_output(0);
function fig_create(src, event)
global __ipy_figures;
__ipy_figures(size(__ipy_figures) + 1) = src;
set(src, "visible", "off");
end
set(0, 'DefaultFigureCreateFcn', @fig_create);
close all;
clear ans;
# ___<end_pre_call>___ #
'''
post_call = '''
# ___<start_post_call>___ #
# Save output of the last execution
if exist("ans") == 1
_ = ans;
else
_ = nan;
end
for f = __ipy_figures
outfile = sprintf('%(plot_dir)s/__ipy_oct_fig_%%03d.png', f);
try
print(f, outfile, '-d%(plot_format)s', '-tight', '-S%(size)s');
end
end
''' % locals()
code = ' '.join((pre_call, code, post_call))
try:
text_output = self._oct.run(code, verbose=False)
except (oct2py.Oct2PyError) as exception:
msg = exception.message
msg = msg.split('# ___<end_pre_call>___ #')[1]
msg = msg.split('# ___<start_post_call>___ #')[0]
raise OctaveMagicError('Octave could not complete execution. '
'Traceback (currently broken in oct2py): %s'
% msg)
key = 'OctaveMagic.Octave'
display_data = []
# Publish text output
if text_output:
display_data.append((key, {'text/plain': text_output}))
# Publish images
images = [open(imgfile, 'rb').read() for imgfile in \
glob("%s/*" % plot_dir)]
rmtree(plot_dir)
plot_mime_type = _mimetypes.get(plot_format, 'image/png')
width, height = [int(s) for s in size.split(',')]
for image in images:
if plot_format == 'svg':
image = self._fix_gnuplot_svg_size(image, size=(width, height))
display_data.append((key, {plot_mime_type: image}))
if args.output:
for output in ','.join(args.output).split(','):
output = unicode_to_str(output)
self.shell.push({output: self._oct.get(output)})
for source, data in display_data:
self._publish_display_data(source, data)
if return_output:
ans = self._oct.get('_')
# Unfortunately, Octave doesn't have a "None" object,
# so we can't return any NaN outputs
if np.isscalar(ans) and np.isnan(ans):
ans = None
return ans
__doc__ = __doc__.format(
OCTAVE_DOC = ' '*8 + OctaveMagics.octave.__doc__,
OCTAVE_PUSH_DOC = ' '*8 + OctaveMagics.octave_push.__doc__,
OCTAVE_PULL_DOC = ' '*8 + OctaveMagics.octave_pull.__doc__
)
_loaded = False
def load_ipython_extension(ip):
"""Load the extension in IPython."""
global _loaded
if not _loaded:
ip.register_magics(OctaveMagics)
_loaded = True