Mailman 3 April 2019 - Matplotlib-users

Constant failed import
by Pierig Havez-Bodivit June 18, 2019

June 18, 2019

Hi, my name is Pierig, I’m a French student, I use python for my study but I’ve got issue with your library. I’m running it on PyCharm and Pyzo on MacOSX and while I can import your library, there's no way of using any of the module, such as : plt.figure() or plt.plot() while other libraries like numpy work. I’ve got this message: I really need your library to work, can you help me with that? Sincerely yours Pierig

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Hexbin plot, PolyCollection and inconsistent facecolor values
by Niklas Berliner May 9, 2019

May 9, 2019

Hi, I am trying to change the edgecolor of some hexbin patches in a hexbin plot. Fiddling around with it to understand how this could work, I encountered a behaviour I cannot understand. I initially opened an issue at seaborn here https://github.com/mwaskom/seaborn/issues/1734 . I get the same behaviour with pure matplotlib and am now asking here for help. Calling get_facecolors() on the PolyCollection returned by plt.hexbin gives different results depending on the jupyter notebook cell within which the call is made. Here's my example (assuming the code is run in a notebook, using Python 3.6.8, NumPy 1.16.2, Matplotlib 3.0.3, Jupyter 4.4.0) Cell 1: ------- import matplotlib import matplotlib.pyplot as plt import numpy as np ------- Cell 2: ------- x = np.array([1,1,1,1.5,1.5,2]) y = np.array([1,1,1,1,1,1]) ------- Cell 3: ------- polycollection = plt.hexbin(x, y, C=np.ones(x.shape), reduce_C_function=np.sum, extent=[1, 2, 0.5, 1.5], gridsize=3, linewidths=1, edgecolors='face') print(polycollection.get_facecolors()) ------- This plots three hexbins with different counts and different colours. Here, get_facecolors() returns a (1,4) array, namely, [[0.12156863 0.46666667 0.70588235 1. ]] Cell 4: ------- print(polycollection.get_facecolors()) ------- When calling get_facecolors() again in the next cell, a (3,4) array is returned, namely, [[0.993248 0.906157 0.143936 1. ] [0.127568 0.566949 0.550556 1. ] [0.267004 0.004874 0.329415 1. ]] The second array seems to be the correct one I think (there are different colors for each of the three hexbins). What is happening here? I am very confused! Thanks, Niklas

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2019 John Hunter Excellence in Plotting Contest Reminder
by Madicken Munk April 26, 2019

April 26, 2019

Hi everybody, I'd like to remind you all about the 2019 John Hunter Excellence in Plotting Contest. My apologies to those of you getting this on multiple lists. In memory of John Hunter, we are pleased to be reviving the SciPy John Hunter Excellence in Plotting Competition for 2019. This open competition aims to highlight the importance of data visualization to scientific progress and showcase the capabilities of open source software. Participants are invited to submit scientific plots to be judged by a panel. The winning entries will be announced and displayed at the conference. John Hunter’s family and NumFocus are graciously sponsoring cash prizes for the winners in the following amounts: - 1st prize: $1000 - 2nd prize: $750 - 3rd prize: $500 - Entries must be submitted by June, 8th to the form at https://goo.gl/forms/cFTB3FUBrMPfQ7Vz1 - Winners will be announced at Scipy 2019 in Austin, TX. - Participants do not need to attend the Scipy conference. - Entries may take the definition of “visualization” rather broadly. Entries may be, for example, a traditional printed plot, an interactive visualization for the web, or an animation. - Source code for the plot must be provided, in the form of Python code and/or a Jupyter notebook, along with a rendering of the plot in a widely used format. This may be, for example, PDF for print, standalone HTML and Javascript for an interactive plot, or MPEG-4 for a video. If the original data can not be shared for reasons of size or licensing, "fake" data may be substituted, along with an image of the plot using real data. - Each entry must include a 300-500 word abstract describing the plot and its importance for a general scientific audience. - Entries will be judged on their clarity, innovation and aesthetics, but most importantly for their effectiveness in communicating a real-world problem. Entrants are encouraged to submit plots that were used during the course of research or work, rather than merely being hypothetical. - SciPy reserves the right to display any and all entries, whether prize-winning or not, at the conference, use in any materials or on its website, with attribution to the original author(s). SciPy John Hunter Excellence in Plotting Competition Co-Chairs Hannah Aizenman Thomas Caswell Madicken Munk Nelle Varoquaux

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[REL] Matplotlib 3.1.0rc1
by Thomas Caswell April 21, 2019

April 21, 2019

Folks, We have tagged Matplotlib v3.1.0rc1. The tarball and wheels are on pypi and can be installed via pip install --pre --upgrade matplotlib conda-forge packages are Highlights of the new features: - A concise date formatter - Secondary axis support (ex, degrees and radians) - A helper method for scatter legends - A progress callback for animations - No longer requires a framework build of Python to use OSX backend - Major and minor ticks will no longer collide by default In addition we have many API deprecations, mostly to obscure corners of the code base, in an effort to make the library more coherent and maintainable. Please test RC and let us know if any of these deprecations break down stream projects. For full details see: https://matplotlib.org/devdocs/users/whats_new.html#what-s-new-in-matplotli… and https://matplotlib.org/devdocs/api/api_changes.html#api-changes-for-3-1-0 I expect there to be at least one more rc and aim for the final release the first week of May. Thank you to all the people who worked on this release! Tom -- Thomas Caswell tcaswell(a)gmail.com

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Query about streamplot
by Dhirendra Kumar April 17, 2019

April 17, 2019

Hii Folks I have an array with dimension (plev: 7, lat: 81). I was trying to draw streamline plot for Omega and V wind [Hadley cell]. I am facing some error with* plt.streamplot* as it says that both the dimension should be of equal size (i.e. N * N ). Is there any other way to create a streamline plot for the data having unequal values along both the dimensions? I seek help of the community in this regard. I hope I framed my question correctly. Please let me know if I need to clarify more details. Thank you -- ======================================== Dhirendra Kumar PhD Student School of Environmental Sciences, JNU New Delhi (India) Contact: +91 9910778043 Alternate email: dhirendra.cub(a)outlook.com =========================================

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how to create 3D plot from a csv or excel
by ramond_yuan April 15, 2019

April 15, 2019

Hello,all: I am a beginner using matplotlib. Can you help me to solve below questions: I want to create a 3D plot from a csv file or excel file. The x axis is “time” The y axis is “RB”（from RB0 to RB49） The z axis is “value” When using matplotlib, I meet to problems:1, the x, y axis is not value, they are text. 2, The z value is not a formula，but corresponding to the table. I cannot found answers from the web, so could any body give me some support. Thanks. Ramond Yuan

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equally spaced nice colors?
by Neal Becker April 1, 2019

April 1, 2019

I'm currently using seaborn to get equally spaced nice colors: import seaborn as sns colors = np.array(sns.color_palette("hls", len (solution))) Now that mpl has all new improved color models, do I still need to use sns or can I easily do something similar with mpl directly?

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