Mailman 3 March 2018 - Matplotlib-devel

Call Notes 26 Mar
by Jody Klymak March 26, 2018

March 26, 2018

Hi all, Call notes are online at https://paper.dropbox.com/doc/Matplotlib-meeting-agenda-aAmENlkgepgsMeDZtls… Folks are welcome to take a look and add items for next week’s agenda (if there is an Easter Monday meeting). If the file doesn’t get too unwieldly, there was general agreement that Paper was a decent way to keep notes and an agenda, at least for now. Cheers, Jody Notes: 26 Mar 2018 • Antony, Hannah, Ryan, Jody Ticks • issues with extra ticks outside viewlims. Antony said they were due to roundoff errors. • maybe trim at Locator level. • deprecate not visible: • ticker.Locator would all need to change • deprecate out of range ticks first, and then expect proper list • epsilon out of viewlims? Keep those. • ticks and lines top and bottom: individual lines for each ticks. • overhaul, single line for top and bottom ticks. LineCollection for grids. • back compatibility? Custom Axes subclass with new Axis subclass…. • each line call is slow (units support). • speed benefit? • can’t manipulate individual tick visibility. Datetime formatting: • https://github.com/matplotlib/matplotlib/pull/10841 • https://github.com/matplotlib/matplotlib/pull/9801 • General agreement locator • General agreement formatter: • needs way to get old beghaviour • useful for teaching/default • @Antony L suggested naming convention • MPLxyDateFormatter • Alias AutoFormatter to current MPLXYDateFormatter • Document “We reserve right to change formatter” • deprecate old linear scalar formatter? • localization of month • Check if way? To merge: • https://github.com/matplotlib/matplotlib/pull/10314 • https://github.com/matplotlib/matplotlib/pull/10158 -- Jody Klymak http://web.uvic.ca/~jklymak/

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note from 2018-03-19 call
by Thomas Caswell March 19, 2018

March 19, 2018

Folks, On call, myself, Eric, Jody, Hannah, Ryan, and Antony. Units: - Ryan taking a summer student is heavy lift - Ryan OK with BDFL-designate for units work 2.2.2 is out! Discussion of colorbar overhaul - big improvement, minor tweaks on log formatter minor ticks Discussion of rcparams overhaul - move to using python's import mechanism - cwd import already wins - use python's 'user install' to do user-level config - this is messier than we would hope - but can use `site.USER_SITE` to get the right path - can provide helper function to install template - install to env / system level for global - users can hack PYTHONPATH to put where ever they want - can gracefully decay to use existing system on failure to import - go though no warning -> warn -> break cycle over 2 years - module must provide function "apply_style(rc : RCParameters): -> None" - styles would work the same way - security concerns pushed back to "arbitrary code execution allows arbitrary code execution", if attacker can put this in the path, then they can modify other files in path. Summer Student: - proposed projects - write altair data structure -> Matplotlib plot - Hannah (primary) and Tom (backup) can mentor, try to reach out to Brian and Jake - details - 6k for 10 weeks - work from home remote - only take one student - Questions for NF - can we pay international students? - what is eligibility requirements on student? - familiar with matplotlib, pandas, jupyter notebooks, python/scipy in general - plus if have used declarative plotting - what level of reporting do you want? - sort out how / where to advertise? - rejected projects - Text / testing - sort out a way to make our tests independent of freetype version - freetype is already working on this - lots of discussion about different approaches to this - mentors? - TODO - write a statement of work - first goal is basic encoding - second goal is transforms - third goal is interactivity Tom

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What minimum version of python3?
by Thomas Caswell March 17, 2018

March 17, 2018

These are derived from today's call: Pro 3.6: - by the time we release, 3.7 will be out so will support "two most recent python" - this gives 3 years of support on master of each python version (assuming python sticks - ordered, faster dictionaries (as implementation detail in 3.6, guaranteed in 3.7) - guaranteed ordered kwargs / class definitions (do precedence of conflicting kwaargs) - fstrings - fspath / pathlib protocol Con 3.6: - feels a bit agressive as 3.7 is not out yet - might get ahead of some LTS releases - but older version of Matplotlib will still work - user-space environments go along way to fixing this - conda - https://www.digitalocean.com/community/tutorials/how-to-install-python-3-an… - ubuntu 18.04 is planned to be py3.6 by default Pro 3.5: - more conservative approach - pypy3 support (but they will support 3.6 eventually) The consensus on the call and on gitter seems to be for 3.6 as the minimum. Tom

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2.2 LTS backport policy
by Thomas Caswell March 17, 2018

March 17, 2018

Folks, I propose the following criteria for backporting PRs to the 2.2.x branch. We always will backport - critical bug fixes (segfault, failure to import, things that the user can not work around) - fixes for regressions against 2.0 or 2.1 Everything else (regressions against 1.x versions, bugs/api inconsistencies the user can work around in their code) are on a case-by-case basis, should be low-risk, and need someone to advocate for and shepherd through the backport. Thoughts? Tom

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[REL] Matplotlib 2.2.2
by Thomas Caswell March 17, 2018

March 17, 2018

Folks, Happy to announce Matplotlib 2.2.2, the second bug-fix release of the v2.2 LTS series. This release fixes a number of critical bugs from 2.2.0: - restores matplotlib.verbose (fixing embedding in pycharm) - preserve precision when color mapping small portions of data with extreme outliers - fixes saving long movies with ffmpeg - fixes UnbourdLocal error in contour labeling - fixes import failure on python 3.4.0 and 3.4.1 - fixes compile time failures with clang on 32bit platforms - fixes an icon in the Tk backends - fixes several issues with Tables - fixes expanding offset boxes with tight_layout - revert changes to the font caching to avoid a possible bug in backports.lru_cache - numerous docstring and documentation fixes We have reverted the deprecation of `font_manager.TempCache`. Thank you to everyone who submitted bug reports and worked on this! v2.2.1 is tagged, but we do not plan to release / publish to pypi. Tom

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Matplotlib v2.2.2 tagged
by Thomas Caswell March 17, 2018

March 17, 2018

Folks, We tagged v2.2.2 (and v2.2.1) today, will rebulid the docs and make broader announcement once wheels are up. REL: v2.2.2 LTS The second bug-fix release of the v2.2 LTS series. This release fixes a number of critical bugs from 2.2.0: - restores matplotlib.verbose (fixing embedding in pycharm) - preserve precision when color mapping small portions of data with extreme outliers - fixes saving long movies with ffmpeg - fixes UnbourdLocal error in contour labeling - fixes import failure on python 3.4.0 and 3.4.1 - fixes compile time failures with clang on 32bit platforms - fixes an icon in the Tk backends - fixes several issues with Tables - fixes expanding offset boxes with tight_layout - revert changes to the font caching to avoid a possible bug in backports.lru_cache - numerous docstring and documentation fixes We have reverted the deprecation of `font_manager.TempCache`. Due to an oversight v2.2.1 did not actually fix the first bullet point which we caught after we pushed the tag, but before uploading to pypi. At this point I do not think we should upload / officially release v2.2.1. Thank you to everyone who worked on this release to fix the inevitable X.X.0 release bugs promptly! Tom

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Documentation
by Matt Arcidy March 16, 2018

March 16, 2018

Hi All, Please forgive the presumption of pulling this topic out of from the meeting thread especially as this is also in a self-introduction email. I want to help with the documentation effort. I read Tom's article in numfocus and the desired skillset rang true. I have 10ish years experience writing tech docs, a few 100+ pages. I write creatively, and I am still somewhat new to matplotlib. I am happy to work in any capacity, though i am most interested in cranking out the first draft of the book. I have looked into the available documentation over the past month+ so I could come with understanding and ideas, some of which I hope are actually good. Both the meeting thread and Tom requested ideas for reorganizing the tutorials and examples as a place to start, so I'll throw one out: explicit definition of an audience, something to which all the documentation can adhere. Right now the tutorials are leveled as beginner, intermediate, and expert, which is great, but it's not clear what that means. Explicitly defining the required skill sets, while not perfect, will allow sorting of concepts and people into each bin. As an example, (please excuse the contrivence): Laura - Sophomore in college - dead set on being a data scientist - 2 programming classes in python - never used any kind of CAD software ever (i.e. does not have any concept of a plot beyond a line on graph paper) Xian - 1 week away from Zoology PhD dissertation, under a deadline - Has used R and Matplotlib to create very basic plots for papers - Wants to create a plot with species heart size over adult weight, with the marker being a jpg of the species' actual heart, beating at the actual species' heart rate on the plot. Ayah - Post Doc or professional - 10+ years of plotting experience using various packages but not matplotlib - has funding to contribute significant functionality, but needs to get up to speed on everything now Obviously this is just beginner, intermediate, expert, but they can be explicitly targeted/taught based on their skill level. Laura needs hand-holding, Xian needs a great API reference, Ayah needs a mosaic of everything and a good architecture map. In the same vein as above, learning paths through the tutorial documents. There are some separable plotting skills, like visually designing the plot, animation, application development, matplotlib development...etc. Each skill could have beginner/intermediate/expert level tutorials which progress naturally, creating a learning tract for each skill. Skills can be stacked to flow into specific roles. Looking at this from outside, the best part about this project is all the information is already there. I have more ideas to dump on you, but I'll postpone until I have a better understanding of where I can fit. Thanks!

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Need some help in 3D surface plotting...
by Phani Kumar March 15, 2018

March 15, 2018

Hi All, I am trying to 3D surface plot the data from a .csv file. there is already a reference plot drawn with this data (seems it was done by some windows app) and I am trying to do the same with linux (in fact on Raspberry Pi) with matplot library. I have attached the .csv file for reference. Original plot (with some microsoft tool) is as below. and when I plot the same data with matplotlib, the plot is as below. Seems the plotting is ok, but for the layer of light orange patches - not sure, what is causing this. My python code is as below. Let me know if you have any suggestion for me. from mpl_toolkits.mplot3d import Axes3D import matplotlib import matplotlib.pyplot as plt from matplotlib import cm from matplotlib.ticker import LinearLocator, FormatStrFormatter import numpy as np import csv X = [] Y = [] Z = [] #Read the selected file with open ('Plasma.csv', 'r') as csvfile: plots = csv.reader (csvfile, delimiter=',') for row in plots: X.append(float(row[0])) Y.append(float(row[1])) Z.append(float(row[2])) #Getting ready for the dispaly fig = plt.figure() ax = fig.gca(projection='3d') #Set the labels... ax.set_xlabel('X (mm)') ax.set_ylabel('Y (mm)') ax.set_zlabel('CPD (mV)') #Setting the places properly... tmp_planes = ax.zaxis._PLANES ax.zaxis._PLANES = (tmp_planes[2], tmp_planes[3], tmp_planes[0], tmp_planes[1], tmp_planes[4],tmp_planes[5]) # Make data. X, Y = np.meshgrid(X, Y) #Plot surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm, linewidth=0) plt.show() With best regards, Phani.

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mplcairo 0.1a1
by Antony Lee March 13, 2018

March 13, 2018

Hi all, I have just pushed a first pre-release of mplcairo to PyPI ( https://pypi.python.org/pypi/mplcairo). As mentioned a few times on the mailing list, it is a new Matplotlib backend based on the well-known cairo library, supporting output to both raster (including interactively) and vector formats. In other words, it provides the functionality of Matplotlib's {,qt5,gtk3,wx,tk,macos}agg, pdf, ps, and svg backends :-) As for any backend, use e.g. by calling `matplotlib.use("module://mplcairo.qt")`, or setting your MPLBACKEND environment variable to `module://mplcairo.qt`. Please check the README for additional information. manylinux, osx, and windows wheels are available (3.6 only; may look into older Python (3...) versions later). On Linux and OSX, the wheels declare a dependency on pycairo (which is how I get a handle onto libcairo); you may want to get it e.g. from conda. On Windows, the wheel includes cairo. I am reasonably confident that the manylinux and windows wheels "work" (of course, feedback is more than welcome), but would particularly appreciate help regarding the OSX wheels. Briefly speaking, for OSX, I have only managed to coerce Travis to build a macos_10_12 wheel (corresponding to the version from Homebrew, and apparently working with it), but conda's Python only accepts wheels up to macos_10_9 (so basically conda's Python can't use the wheels: you need to build mplcairo yourself); moreover, because it appears impossible to statically link libc++ on OSX, mplcairo specifically needs to be imported before matplotlib. If you don't, mplcairo won't eat your data, but may well segfault your process. Any insight regarding the intricacies of cross-version compatibility and/or dynamic loading on OSX would be appreciated... Enjoy (hopefully :-)), Antony

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py.test can't find ft2font
by swfiua＠gmail.com March 9, 2018

March 9, 2018

I am trying to get tests passing again for this pull request: https://github.com/matplotlib/matplotlib/pull/8325 They are failing due to differences in the images the latest code is generating. The tests themselves advise me to build with "local_freetype=True" in setup.cfg and I am doing this. I am building/installing matplotlib with: python3.6 setup.py build and python3.6 setup.py install --user If I fire up python3.6 then from matplotlib import ft2font works just fine. But when I run py.test it fails to find it. Curiously, python3.6 -m matplotlib.ft2font is also unable to find ft2font. John

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