Mailman 3 March 2019 - Matplotlib-devel

What is draw_path's transform's destination?
by Rob McDonald Sept. 24, 2019

Sept. 24, 2019

I'm implementing a custom path effect by inheriting from AbstractPathEffect and implementing draw_path as instructed here <https://matplotlib.org/api/patheffects_api.html#matplotlib.patheffects.Abst…>. That link references RenderBase.draw_path <https://matplotlib.org/api/backend_bases_api.html#matplotlib.backend_bases.…> to define the required interface. Unfortunately, I can't find anywhere in the associated documentation that tells me what the transform argument really entails. I've also read the transforms tutorial <https://matplotlib.org/tutorials/advanced/transforms_tutorial.html>, and while that explains the pipeline and all the intermediate transformations, it doesn't really settle what I have available to me in draw_path. It is clear that I can use it to transform coordinates from data to something -- but I don't know what to. For the big picture -- I am implementing a path effect to allow drawing hatched lines similar to this <https://www.mathworks.com/matlabcentral/fileexchange/29121-hatched-lines-an…>, which I did years ago in Matlab. Years before that, I've also done this in Java Graphics2D by implementing a custom stroke. (The Java approach is more applicable to the path effect approach, but I can't point to that code online anywhere.) Anyway, I have things mostly working -- and I am using the transform to go from data coordinates to something that looks orthogonal and reasonable on-screen. So, for minimum functionality, it works. However, I want to give the user the ability to control the length and spacing of the hatches -- which is in a coordinate system after the transformation is applied. So, in order to document this thing, I need to know what it is. Or, if there is a way to get intermediate stages of the transformation pipeline, that would work too. As for the user interface -- it seems to make the most sense to specify the hatch length and spacing in terms of something similar to a line width (typically points) or a marker size. I'm new to Python and matplotlib -- what is the Pythonic unit a user would expect to specify this in (and how do I achieve that with what is available in draw_path)? Thanks, Rob

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matplotlib qt trading terminal; finance sample
by cerberus cerberus April 19, 2019

April 19, 2019

Hello Lists, I will park my matplotlib source code for a trading terminal written in python2/matplotlib/pyqt4 here in case one needs reasonable good reference code about how to plot financial candlestick charts and indicators with matplotlib and qt. A sample of a combined orderbook for several crypto currency exchanges is included, see attached screenshot. Google Notice: Wavetrend Robot. With Kind Regards, Aktiophi

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Seeking GSOC 2019 Students
by Hannah March 28, 2019

March 28, 2019

Hello, Matplotlib is participating in Google Summer of Code this year under the Numfocus umbrella. Applications are due April 9. Please apply and encourage students you may think are a good fit to apply. Application instructions are at https://github.com/numfocus/gsoc Applicants are welcome and encouraged to propose their own projects or build on the project we have proposed, which is a collaboration with the geopandas library. GeoPandas allows users to work with geospatial data in Python by providing geospatial operations in Pandas and a high-level interface to multiple geometries to shapely. It also facilitates exploratory visualization of geospatial data via descartes and matplotlib. The visualization interface in geopandas is currently on the rough side; it generates simple polygon based maps that are inconsistent in terms of supporting matplotlib features such as color mapping and color bars. Find more information at https://github.com/matplotlib/matplotlib/wiki/GSOC-2019-Ideas-Page Please respond to this email with questions or ask here: https://gitter.im/matplotlib/matplotlib?utm_source=share-link&utm_medium=li… Thank you,

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BoF submission to SciPy 2019
by Matthias Bussonnier March 15, 2019

March 15, 2019

Hello Matplotlib List, The SciPy conference would like to encourage you to submit proposals for Birds of a Feather (BoF) sessions at this year's SciPy! BoFs usually include short presentations by a panel and a moderator with the bulk of the time spent opening up the discussion to everyone in attendance, but the format is flexible. BoF topics can be of general interest, such as state-of-the-project BoFs, or based on the themes of the conference and the mini-symposia topics, or can be a great opportunity to collect informations from members of the SciPy community. We would like to encourage you to think about topics of interest and submit your proposals. Submission will be opened on March 18, 2019 (This Monday) and close on Friday, May 31st, 2019. You can submit you proposal here: https://www.scipy2019.scipy.org/bof-sessions. Past SciPy conferences have had a large variety of BoF sessions, including topics on Reproducibility, Jupyter Notebooks, Distributed Computing, Geospatial Packages in Python, Teaching Scientific Computing with Python, Python and Finance, NumFOCUS, Python in Astronomy, Collaborating and Contributing in Open Science, Education, and a Matplotlib Enhancement Proposal Discussion. Generally, if there is a topic where you think a number of people at SciPy will be interested, you should propose it! Please share this with anyone else in the community who you think would be a good candidate for organizing a BoF. The BoF committee will try to select the BoFs based on a number of criteria, and/or attempt to merge BoFs submission with a large overlap. Thanks in advance for your submission, and looking forward to see you at SciPy 2019, Austin Texas, July 8-14, 2019. Feel free to contact us if you have any questions, concerns or suggestions. -- Lindsey Heagy and Matthias Bussonnier for the SciPy organizers. scipybofs(a)gmail.com

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google season of docs
by Thomas Caswell March 12, 2019

March 12, 2019

Folks, Google is trying out a documentation version of GSoC [1]. Is anyone interested in leading this from our side? Tom [1] https://developers.google.com/season-of-docs/ -- Thomas Caswell tcaswell(a)gmail.com

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Interpolations in Line2D objects
by Raymond Osborn March 11, 2019

March 11, 2019

Is there any interest in adding an interpolation attribute to axes.Line2D objects similar to those in Axes.imshow? We often use bicubic interpolation using spicy.interpolate to generate smooth lines to connect markers, partly for aesthetic reasons, but partly for (what we maintain are) valid scientific reasons. However, there is no way to display the line along with the associated marker in legends, and it generates additional Line2D objects that are not really separate entities. I haven’t looked into how this might be done but I thought I would check first to see if this has been considered before and rejected for any reason. It obviously requires storing additional smoothed arrays and smoothing options, and perhaps there are other complications I am not aware of. Ray

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Software 3D Renderer
by Nicolas Rougier March 9, 2019

March 9, 2019

I’ve coded a small pure Python 3D renderer (100 lines with loader, z-buffer, transformation, texture & light) available at https://github.com/rougier/tiny-renderer. But I’ve no idea if any part can be re-used for the 3D axis in matplotlib. Nicolas

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Fwd: Mentored sprints for underrepresented folks @PyCon US
by Northwest UK PyLadies March 5, 2019

March 5, 2019

Mentored sprints for diverse beginners: May 4th 2019, 2:35pm Join us for the first PyCon US mentored sprints for diverse beginners We are very excited to announce the mentored sprints for diverse members of the Python community 🎉🐍🙌 *When: *4th of May 2019 from 2:35pm to 6:35 pm, during the main section of PyCon. Its main aim is to support folks from underrepresented groups in our community that want to start contributing to open source projects. We will provide mentorship during the day as well as git support and an introduction to open source contributions. *Applications for mentors and attendees are open until the 14th of March 2019!* Mentors /maintainers We are looking for mentors and/or core developers/maintainers of open source projects interested in taking part in the sprint and mentor the attendees over the day. What you need to know - The sprint will last from 2:35pm - 6:30pm but it will be divided in two slots of 2 hours so you can choose between a 2 and 4 hours commitment to the sprint. - You do not need to maintain a project or to have merge access to a project to mentor on the day - There can be more than one mentor per project. We will provide you with guidance and help to prepare for the day (i.e. have beginners friendly issues, provide advice on how to better serve a diverse community, and provide you with as much support as needed. - You do not need previous experience with sprints and/or mentoring. Go to mentors sign up <https://goo.gl/forms/YCZP5auVi5ZFtMjg1> Contributors/attendees - You do not need to have previous experience contributing to open source - We will provide on-site guidance and mentoring - We strongly encourage members from underrepresented groups in our community to attend - It is a great opportunity to learn and meet others in the community Go to contributors sign up <https://docs.google.com/forms/d/e/1FAIpQLSfmUDvXXHRgkBpYcHpy6O3txHEeLihz6g7…> If you want to contact the organisers please email us at nwuk(a)pyladies.com For more details visit https://us.pycon.org/2019/hatchery/mentoredsprints/ Please share with your network 🐍 [image: OR] Share this [image: Fb] <http://www.facebook.com/sharer.php?u=https://us.pycon.org/2019/hatchery/men…> [image: Tw] <https://twitter.com/share?url=https://us.pycon.org/2019/hatchery/mentoredsp…> [image: In] <http://www.linkedin.com/shareArticle?mini=true&url=https://us.pycon.org/201…> Tania, Mariatta, Nina and Nikoleta

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REL: Matplotlib 2.2.4 and 3.0.3
by Thomas Caswell March 2, 2019

March 2, 2019

Folks, As we get ready for 3.1 (aiming for mid-to-late March), we have tagged 2.2.4 and 3.0.3 bug-fix releases. Wheels for all three platforms are on pypi for both releases. 3.0.3: The third and last planned bug-fix release of the 3.0 series * fix several possible memory leaks * documentation fixes 2.2.4 The forth bug-fix release of the v2.2 LTS series. - Fix a memory leak with PySide2. - rename :math: sphinx directive to :mathmpl: to work with sphinx > 1.8. Both versions are now available if sphinx < 1.8. - avoids numpy deprecation warnings. - fixes to tests to work with pytest >= 3.8 and the minimum is now pytest >= 3.6. As a reminder, the 2.2 LTS series will continue to support Python 2.7 and get critical bug-fixes until the end of 2019. In both cases jquery-ui is no longer bundled in git repo and is downloaded during the install or sdist process. If you are installing from pypi the files will be included, but if you are installing from git you will need internet access the first time you run `pip install .`. The install process tries to cache the files and will not need internel access on future installations. I big thank you to everyone who worked on these releases done. Paul Ivanov was co release manager with me on both releases. Tom -- Thomas Caswell tcaswell(a)gmail.com

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