Mailman 3 September 2016 - Matplotlib-users

Advanced usage of custom hatch with fill_between
by christian＠fredborg-braedstrup.dk Sept. 28, 2016

Sept. 28, 2016

Hi, I would like to make some quite advanced custom hatches and can't figure out the best way to do it in matplotlib. I am not even sure hatches are the best way too go about it. Have considered using a png or similar and overlay that on the image. But I would like to use the fill_between command and that does not support using pngs in that way. Here is a example of what I would like my hatch to look like, http://fredborg-braedstrup.dk/hatch_examples.png This stack overflow question got me a bit of the way: http://stackoverflow.com/questions/17285154/how-to-fill-a-polygon-with-a-cu… I have therefore made a polygon to draw the "T" like symbol on a unit rectangle, T_path = Polygon( [[0.0, -0.2], [0.0, 0.0], [-0.4, 0.0], [0.4, 0.0], [0.0, 0.0], [0.0, -0.4]], closed=True, fill=False).get_path() but the symbols are too small and closely spaced. I have a example here, http://fredborg-braedstrup.dk/hatch_mpl_example.png Is it possible to enlarge the individual symbols (T's) without having them clip on the unit rectangle? Or perhaps it is possible to only plot every 5th symbol? It seems quite easy when creating hatch lines and adding space but I have not found a good solution for general polygons yet. If a solution exists without using hatches I am all open to that. Hope someone can point me in the right direction on this. Thanks, Christian

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How to blur "add_patch(Rectangle(..."
by Xavier Gnata Sept. 26, 2016

Sept. 26, 2016

Hello, The code in attachment produces a checkerboard pattern made of rectangles. How could I blur only some of these Rectangle? Is it possible to add a filter on top of a currentAxis.add_patch(Rectangle( ... ? Xavier

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matplotlib: no output with Agg - TkAgg - Qt5Agg -- stuck at ttconv.so
by Thierry Sept. 23, 2016

Sept. 23, 2016

Hello, I use python/matplotlib scripts regularly to produce nice figures from raw data files. After the summer break I did an update of my Gentoo box and I have now a problem with matplotlib. It produces no graphical output: no pop-up window with a graph and no way to save a plot. I have tried to change the backend : with TkAgg or Qt5Agg the process is stuck forever <defunct> and to be killed manually kill -9, with Agg it is slightly better, I get back the command line but the pdf file created is not complete, unreadable by Okular. here are the versions: so it's gentoo box kernek is 3.10.17 python 2.7.10 dev-python/matplotlib-1.5.3 I use also ipython-5.1.0 which shows the same problem. I tried the new jupyter qtconsole which hangs when displaying a plot. I ran a minimal script that contains the problem: ************************************* from pylab import * x=[1.,2.,3.] y=[2.,3.,4.] plot(x,y,'o') savefig('myf.pdf',format='pdf') ************************************* the same behavior arises in interactive shell, calling directly matplotlib directly instead of pylab. running the script with python -v my_script.py gives a very verbose output whose end is: .... import matplotlib.backends.qt_editor.formsubplottool # precompiled from /usr/lib64/python2.7/site-packages/matplotlib/backends/qt_editor/formsubplottool.pyc # /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_pdf.pyc matches /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_pdf.py import matplotlib.backends.backend_pdf # precompiled from /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_pdf.pyc # /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_mixed.pyc matches /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_mixed.py import matplotlib.backends.backend_mixed # precompiled from /usr/lib64/python2.7/site-packages/matplotlib/backends/backend_mixed.pyc # /usr/lib64/python2.7/site-packages/matplotlib/type1font.pyc matches /usr/lib64/python2.7/site-packages/matplotlib/type1font.py import matplotlib.type1font # precompiled from /usr/lib64/python2.7/site-packages/matplotlib/type1font.pyc dlopen("/usr/lib64/python2.7/site-packages/matplotlib/ttconv.so", 2); import matplotlib.ttconv # dynamically loaded from /usr/lib64/python2.7/site-packages/matplotlib/ttconv.so it dies right at ttconv.so the process is then <defunct> should be killed with -9 Looking for ttconv.so seems OK ... tjoli@skynet matplotlib % file ttconv.so ttconv.so: ELF 64-bit LSB shared object, x86-64, version 1 (GNU/Linux), dynamically linked, stripped tjoli@skynet matplotlib % ldd ttconv.so linux-vdso.so.1 (0x00007fffe9b1f000) libstdc++.so.6 => /usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/libstdc++.so.6 (0x00007f85f6445000) libpython2.7.so.1.0 => /usr/lib64/libpython2.7.so.1.0 (0x00007f85f6076000) libgcc_s.so.1 => /usr/lib/gcc/x86_64-pc-linux-gnu/4.9.3/libgcc_s.so.1 (0x00007f85f5e5f000) libc.so.6 => /lib64/libc.so.6 (0x00007f85f5ac3000) libm.so.6 => /lib64/libm.so.6 (0x00007f85f57c4000) /lib64/ld-linux-x86-64.so.2 (0x00007f85f6a0c000) libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f85f55a8000) libdl.so.2 => /lib64/libdl.so.2 (0x00007f85f53a4000) libutil.so.1 => /lib64/libutil.so.1 (0x00007f85f51a0000) If I use Agg then the end of the output with '-v' is the same but I get back the command line. No appearance of the usual cleanup messages that appear after a successful run. Any ideas would be welcome thanks in advance. (In case it is gentoo-specific I posted this problem on the gentoo forum - no answers yet.) -- View this message in context: http://matplotlib.1069221.n5.nabble.com/matplotlib-no-output-with-Agg-TkAgg… Sent from the matplotlib - users mailing list archive at Nabble.com.

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Plotting and formatting dates
by Florian Lindner Sept. 23, 2016

Sept. 23, 2016

Hello, I have read data with dates using numpy.genfromtxt. The resulting data format is ['datetime64[D]', np.float32, np.float32]}. Plotting the data works perfect: dates = finances["Date"] bar = np.cumsum(finances["Bar"]) giro = np.cumsum(finances["Giro"]) total = bar + giro fig, ax = plt.subplots() ax.plot(dates, bar, "-d", label = "Bar") ax.plot(dates, giro, "-d", label = "Giro") ax.plot(dates, total, "-D", label = "Gesamt", linewidth=3) but using a date formatting for the x-axis and a currency format for y-axis does not work: def formatCurrency(x): return '%1.2f €' % x locator = matplotlib.dates.AutoDateLocator() ax.xaxis.set_major_locator(locator) ax.format_xdata = matplotlib.dates.AutoDateFormatter(locator) ax.format_ydata = formatCurrency fig.autofmt_xdate() ax.grid() ax.legend() plt.show() It simply shows no effect, no € sign at y-data, the x-data is still an int-like number. What am I doing wrong? Thanks, Florian

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NumFOCUS Projects Director
by Thomas Caswell Sept. 21, 2016

Sept. 21, 2016

Forwarded on on behalf of NumFOCUS. Please distribute this through your networks! NumFOCUS is seeking to hire a full-time Projects Director to develop and run a sustainability incubator program for NumFOCUS fiscally sponsored open source projects. This is the first program of its kind, with opportunity for enormous impact on the open source ecosystem. The Projects Director will work with NumFOCUS fiscally sponsored Open Source projects to develop appropriate business development strategies and opportunities to engage with industry. The learnings from this program will be public, meaning it has the potential to change how all open source projects are managed. NumFOCUS is 501(c)3 whose mission is to promote sustainable high-level programming languages, open code development, and reproducible scientific research. They accomplish this mission through their educational programs and events as well as through fiscal sponsorship of open source data science projects. They aim to increase collaboration and communication within the scientific computing community. The Projects Director position is initially funded for 2 years through a grant from the Sloan Foundation. The incumbent will be hired as an employee of NumFOCUS. Review of applications will begin October 10th, and the position will remain open until filled. Job description The Projects Director will lead efforts to identify skills and perspectives that Open Source Project leads need to establish sustainability models and seek opportunities for funding and will consult with NumFOCUS projects and disseminate outcomes. Responsibilities Include: - Organize a ‘business bootcamp’ workshop, coach project leads and lead an Advisory Board for these business development efforts - Develop business and financial plans, improve communication, build industry relationships, and broadly develop strategies for fostering these relationships. - Lead efforts to identify skills and perspectives that Open Source Project leads need to establish sustainability models and seek opportunities for funding - Using materials from workshops and other resources, develop and disseminate an Open Source Nurturing and Actionable Practices Kit (OSNAP Kit) to provide guidance to open source projects outside of NumFOCUS - Establish assessment strategies to measure impact and help NumFOCUS open-source projects develop industry relationships Qualifications As this role provides a business, operations and marketing perspective to Open Source project leads, the candidate should have: - Preferred: 4 years experience in business development, operations and/or marketing - Strong oral and written communication skills - Teaching experience of some capacity, e.g. teaching at universities or creating and running workshops - Demonstrated ability to interact with a broad range of people from technical leads to industry leaders - Experience working with open communities, e.g. open source software, hardware or makers, - A rich network of experts in business and technology to draw ideas and collaboration from. Salary NumFOCUS offers a competitive salary commensurate with experience and a comprehensive benefits package. Applications To apply, please submit your resume/CV and cover letter (up to two pages) to NumFOCUS at: projects_director(a)numfocus.org See the posting at: http://www.numfocus.org/blog/projects-director-job-posting

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How can I speed up a tricontourf call ?
by Francis Chabouis Sept. 15, 2016

Sept. 15, 2016

Hello, I'm working on this travel times project : https://ubikiwi.com/ouhabiter?locations=[[48.85522811385678,2.3321914672851… and the contouring is done thanks to MPL tricontourf function (thanks!). As you can see it works pretty well and is fast enough. As I'm trying to expand the geographical coverage of the application (the whole country) I'm having performance issues with the contouring: - if I load the triangulation in memory at startup, it takes a huge amount of RAM. But the real problem is that even a very small contour in this huge triangulation takes a very long time to produce. For example with a small triangulation, a 20 minutes walk isoline is instant. The same contour on a country-wide triangulation takes 6sec. (It is not that long, but for a web application it is). - If on the other hand I compute a triangulation for each request, the contouring is fast but the triangulation creation is slow. Would someone have an optimisation idea ? Is it somehow possible to speed up the triangulation ? Any possible alternative ? Thanks a lot, Francis

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Simultaneous plots with Matplotlib "QObject/thread" error
by John Robson Sept. 10, 2016

Sept. 10, 2016

Hi all, I have some Flask pages that plot charts using Matplotlib, they work very well, but when running them simultaneously they break the site, with errors like: "QObject: Cannot create children for a parent that is in a different thread." "QObject::~QObject: Timers cannot be stopped from another thread" I wonder how to safely use Matplolib with Flask (with several simultaneous users plotting charts all the time)? Thank you, John

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Documentation help request for web frameworks
by Thomas Caswell Sept. 6, 2016

Sept. 6, 2016

Folks, I know that there is a use of mpl as part of django / flask / bottle / zope / ... to write figures directly to buffers and serve them to users without writing to disk (an example of this is http://scipy-cookbook.readthedocs.io/items/Matplotlib_Django.html , but I think this is better done via `fig.savefig(bytes_io_buffer, format='png')` rather than reaching in and touching the canvas directly). This seems like the sort of thing that should be easy to find in our documentation. Is anyone interested in writing up 'canonical' examples? Tom

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