Is there a python equivalent of the prefuse visualization toolkit? - python

The prefuse visualization toolkit is pretty nice, but for Java. I was wondering if there was something similar for python. My primary interest is being able to navigate dynamic graphs.

I know this is not exactly python, but you could use prefuse in python through jython
Something along the lines of:
Add prefuse to your path:
export JYTHONPATH=$JYTHONPATH:prefuse.jar
and
>>> import prefuse
from your jython machinery
this guy has an example of using prefuse from jython here

You might want to check out SUMMON, a visualization system that uses python but handles fairly large data sets. There's an impressive video of visualizing and navigating a massive tree. (Can't post the link because I'm a first time poster. It's on the SUMMON front page.)

If you're using a Mac, check out NodeBox. One extension it offers is a graph library that looks pretty good. Poke around in the NodeBox gallery some to find something similar to your problem and it should have some helpful links.

This is well after OP, but just in case:
pydot. Allows generation & rendering of graphs. If you need graph algorithms (transitive closure etc.) also look at pygraphlib which extends and integrates pydot.
Note that neither allows interactive editing of the rendered diagram. They both use graphviz to generate output.

You could try using prefuse with JPype, if you can't find a suitable replacement.

Note that prefuse now has the flare package which uses flash.
Connect that to a Python backend via web2py and you've got a great web app (just an idea).

MayaVi

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Convert AsciiMath/MathML to SVG/PNG

I'm looking for a way to convert my AsciiMath (or MathML) sources to SVG and/or PNG. I've found a nodeJS library for SVG conversion but calling that from Python is not very convenient and the output is not entirely satisfying.
Taking the fact I'd like to render mathematical formulas to svg/png it seems logical to look for a solution in math libraries (NumPy, SciPy, Pandas, Matplotlib, Sympy, etc...) but to no avail. All my google results combining all possible permutations of asciimath+mathml+svg+png lead to nothing which is strange.
Please recommend me either search patterns to find a solution or share your experiences/ideas to get this seemingly simple job done in Python.
All help would be highly appreciated!
I just created ziamath for exactly this purpose. It comes bundled with the STIX math font, so no setup is required beyond the pip install, but it should also work with other math-enabled fonts. Pure-Python, so it does not need a Latex installation or anything else to work. This first version doesn't quite cover the full MathML specification, but the most useful parts are in there.
To bundle it into an app with something like PyInstaller, you'll need to make sure the STIX font gets included, but that should just be one line in the PyInstaller config.
I have used this for years without issues. It is written in python.
https://sourceforge.net/projects/svgmath/files/svgmath/0.3.3/

graphically (GUI) test Python scripts like jsfiddle

I'm exploring 2D interpolations for the purpose of writing a script in Python. I've been using the PIL (Pillow) modules to quickly display the results of the algorithms - this is best for cases when interactive input isn't necessary (i.e. testing on a random set of points).
For interactive testing I've found jsfiddle to be the most lightweight solution, but I admit it isn't ideal to rewrite functions in another language merely to be able to move points around, and input specific shapes of quads.
simple example, 4 verts drawn at random (JavaScript in JS fiddle; would like to do the same in Python)
What would be a fastest way to play around with a Python script graphically? Is there a Python counterpart of jsfiddle? I googled 'Python fiddle', of course, but it's not what I'm looking for. What I need is a simple canvas implementation and click events support.
Thanks in advance,
Well, there is Python Fiddle, but I think this question is going to be closed by admins as being off-topic on Stack Overflow; see this thread here.
I'd also come to think of Jupyter and Anaconda. The latter includes the former. These will harness matplotlib, amongst others, and Jupyter gives you a Matlab-like interpreter that shows you variable values for each line and you're able to step by step look at those variables and any graphs you are making.
As mentioned in previous answer, there is Jupyter notebook – a software for interactive Python programming including graphical output.
You can run Jupyter locally or on your own server, but there are free cloud versions:
https://colab.research.google.com/
https://notebooks.azure.com/

(ArcGIS) Create new function for Arcpy

As a result for my graduation paper I am trying to create a new toolbox for ArcGIS using Python scripting. The problem is I am stuck with my code because none of the existing functions in Arcpy does what I need to do. So my question is, is it possible to create a new function in Arcpy or this is restricted to ESRI developers?
Another way to solve this problem would be implement some changes in the tool Cost Distance from Spatial Analyst. So my other question is, do I have access to the coding of the native tools from ArcGIS? And if I have, can I change it to achieve my goal? Or this is also restricted?
Thanks,
Gabriel
You can create your own functions using Python and the Python arcpy site-package. All of ESRI's tools are proprietary, and therefore, most have restricted access. You can check to see if you can edit the tools in the ArcToolbox. For example, you can see the Cost Distance tool is restricted:
While the Spline with Barriers tool can be edited by right-clicking on the script tool.
You can create your own python toolbox for ArcPy following this help: http://resources.arcgis.com/en/help/main/10.2/index.html#//001500000022000000
also checkout the environment variables for your existing tool, it might have some options that you are looking for.
I know this is a year late, but I would like to add a couple ideas to what has been posted for folks like me who are searching for python toolbox help.
For educational purposes, begin by creating a model in Model Builder. This is one way to use ESRI's proprietary tools in new ways. Decide what you want to do and look at ESRI's presence on GitHub. The developers there have a lot of open-source tools ready to use in ArcMap. Here is one such repository: GeospatialPython
Side note, contributing to a repository is a great resume builder.
After creating your working model builder, right click on it in ArcCatalog and select 'export as Python script'. Open the script in your favorite IDE and begin cleaning it up!
Now that you have a python script, it is ready to become a python toolbox. Use gDexter42's link and get to work on that.
My team has some interesting uses for python toolboxes and I am currently creating my very first one.
We use a runner scripts to debug our software. (hard-coded parameters)
We use inheritance for functions that we use over and over again (class BaseToolboxMixin(object):) Stack Exchange Article on Mixins
Most importantly, we have created our own python module around the tool.
The .pyt file we made simply imports arcpy, the module we created, executes the module from a list we created in our 'toolbox_loader.py' file, and has a class that calls the init file that created the module in the first place. >20 lines of code.
As our team creates more tools for the module/python toolbox, we will add them to the list. They will appear inside our toolbox alongside all the ESRI tools. "Seamless integration" was thrown around a lot at the Dev Summit this year.
ESRI is encouraging creativity and open-source usage (check out esri leaflet). I wouldn't constrain my thinking because ESRI's tools are proprietary.
All of this functionality began as a model in ArcMap. Not everyone is going to need to create their own module - complete overkill for most tasks - but it is good to know that the ceiling for Python functionality is high. I am not an experienced developer, but I was able to go from nothing to a functional python toolbox in about 25 man-hours of work. Someone who knows their stuff could do it in a morning.

Easiest paths from Pygame/PyOpenGL to iOS.

I have a significant game I really need to port to tablets. (Android has PyGame subset for Android, which I'm still investigating). It would be great to take my Python code and move it to a more cross-platform engine.
I'm looking for engines with a pure code API, something I can wrap my intermediate glue for graphics and audio around. Kivy and some others use too much *ML (or JSON). Hoping I missed something good. The best I've seen is Futile for Unity3D, but Boo !!!!!= Python.
Have a look at http://ignifuga.org, it's Python based and inspired by projects like Cocos2d and AndEngine.
Have a look at Kivy framework. I tried just some very simple demos but I can confirm that you can run it on PC/Mac/iOS.

Graphing in Python 3.x

In Python 2.6, I used matplotlib to make some simple graphs. However, it is incompatible with Python 3.1.
What are some alternative modules that can accomplish the same thing without being very complex?
You say you want to create some simple graphs but haven't really said how simple or what sort of graphs you want. So long as they aren't too complex you might want to consider using the Google Chart API.
e.g.
That has some advantages: you just have to construct a URL that describes the desired chart so there shouldn't be any issues using it from Python 3.x. Of course there are disadvantages also: you need to have an internet connection when generating the chart, and you might not have the chart styles you have been using with matplotlib.
If you don't want to construct the URLs directly there is at least one Python wrapper for the charts API. It doesn't work directly on Python 3.x, but running it through 2to3 seems to convert it successfully.
A stable version supporting Python 3 has since been released: official announcement.
I wrote a small example that runs in python 3 and uses the google chart api (as suggested by Duncan, I wrote the solution after seeing this post).
It is not ideal since it adds a dependency one a 3rd party that might break backward compatibility at any time, but the graphs are nice and there is absolutely no added dependency on the python code. Worth considering for not 'mission critical code'.
You can find/download the example here. Here is the graph that it generates from data in a .xml file:
# build the query with template parameters
query ="http://chart.apis.google.com/chart?chxl=0:__X_LABELS__&chxp=__X_LABELS_POS__&chxr=0,__MIN_TIME__,__MAX_TIME__|1,__MIN_WEIGHT__,__MAX_WEIGHT__&chxs=0,676767,11.5,0,lt,676767|1,676767,11.5,0,lt,676767&chxt=x,y&chs=800x300&cht=lc&chco=3072F3&chds=__MIN_WEIGHT__,__MAX_WEIGHT__&chd=t:__COMMASEP_WEIGHT__&chdl=Weight&chdlp=b&chls=2,4,1&chma=5,5,5,25&chtt=Your+Weight+Timeline"
[...]
# relace template with data
query = query.replace('__X_LABELS__', strXLabels)
query = query.replace('__X_LABELS_POS__', strXLabelsPos)
query = query.replace('__MIN_TIME__', str(min(lst_dateEpoch)))
query = query.replace('__MAX_TIME__', str(max(lst_dateEpoch)))
[...]
# use 'urllib.request' to download the data & write to file
sock = urllib.request.urlopen(query)
image_bytes = sock.read()
sock.close()
fh = open('Weight_GoogleGraphApi.png', 'wb')
fh.write(image_bytes)
fh.close()
Maybe PyQwt? They claim 3.x compatibility. I've only used Qwt (the C++ lib PyQwt is based on) but I found it fairly useful.
rpy2 is providing access to the graphics capabilities of R, and rpy2 is becoming compatible with Python 3 (thanks to the help of Google for funding Greg over the summer).
Code against the current dev branch is in a patch queue.
edit: rpy2 2.2.0 is working with Python 3.2
MathGL (GPL plotting library) have Python interface which work with Python 3 too.
Matplotlib binaries for python 3.x (windows) are avaliable. http://www.lfd.uci.edu/~gohlke/pythonlibs/
As an alternative to installing subversion to grab the source, Numpy's SF files page has the latest copy of 1.5 in a few different (Windows-friendly) formats:
http://sourceforge.net/projects/numpy/files/NumPy/1.5.0b1/
There are at least two graphing libraries using PyQt, namely PyQwt and PyQtGraph. I've been using PyQwt with Python 2.6 for a few weeks now and it is quite handy. The documentation isn't great, and most of the time I need to refer to either the Qwt docs or the examples - although the times I've had to look at the docs have been few and far between, it is VERY easy to use. I tried building it against python 3.1 just now though without success. I coulnd't find the tar package for 5.2.1 which is the only version compatible with python 3.0 and there isn't anything on MacPorts for that either.
There is also a fairly complete looking list of plotting libraries on at python.org http://wiki.python.org/moin/NumericAndScientific/Plotting

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