Mailman 3 February 2018 - Matplotlib-users

ToolManager
by Juan Nunez-Iglesias April 28, 2018

April 28, 2018

Hi, I’m trying to add elements to the matplotlib toolbar *using the Qt5 backend*. I tried running this example code: https://matplotlib.org/examples/user_interfaces/toolmanager.html But unfortunately it fails when using Qt5 with the error fig.canvas.manager.toolmanager.add_tool('List', ListTools) AttributeError: 'FigureManagerQT' object has no attribute ‘toolmanager' Is toolmanager only available for GTK? Is there an equivalent way of achieving what the script is doing in other backends? Thanks, Juan.

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automatic list of r'$2$'...
by Vincent Douce Mathoscope April 20, 2018

April 20, 2018

hi i try this : ''' Lx,x,Ly,y=[],xmin,[],ymin Lrx,Lry=[],[] while (x<=xmax): Lx.append(x) Lrx.append("$".join(["r'",str(x),"'"])) x+=1 while (y<=ymax): Ly.append(y) y+=1 ''' but it creates a Lrx list like this : ["r'$-2.5$'", "r'$-1.5$'", "r'$-0.5$'", "r'$0.5$'", "r'$1.5$'", "r'$2.5$'"] and i want to obtain [r'$-2.5$', r'$-1.5$', r'$-0.5$', r'$0.5$', r'$1.5$', r'$2.5$'] i guess that r is an operator to deal with the $..$ expressions but not understand how to fix my definition thanks for your help Vincent –––––––––––––––––––––––––– Vincent Douce :=: Mathoscope :=: http://mathoscope.xyz <http://mathoscope.xyz/> 06°13°11°07°26 Bagnères de Bigorre 65200

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Callback mechanism for animation completed?
by Paul Deitel April 20, 2018

April 20, 2018

I am trying to chain together a series of animations. Is there a callback mechanism of some sort that could be used to launch a new animation when another animation completes?

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Efficiency in connecting two subplot.
by Éric Depagne March 3, 2018

March 3, 2018

Hi all, I have a gridspec plot and one of the subplot is a zoom on the part over which the mouse hovers on another subplot. It works, but I think the way I implemented it is not very efficient, since each time I use it, I see one CPU go to 100%. Here is the code that does implement the zoom. Any idea on how to make it (more) efficient or changes that I should implement welcome. Thanks. def plot(self): gs = gridspec.GridSpec(6, 2) ax1 = plt.subplot(gs[1:, 0]) plt1 = ax1.imshow(self.data, vmin=self.dataminzs, vmax=self.datamaxzs) ax1.set_label('AX1') self.ax2 = plt.subplot(gs[0:3, 1]) zoomeddata = self.data[np.int(self.data.shape[0]/ 2)-50:np.int(self.data.shape[0]/2)+50, np.int(self.data.shape[1]/ 2)-50:np.int(self.data.shape[1]/2)+50] self.plt2 = self.ax2.imshow(zoomeddata, vmin=self.dataminzs, vmax=self.datamaxzs) ax1.figure.canvas.mpl_connect('motion_notify_event', self._on_move) def _on_move(self, event): zoom1 = 100 if event.inaxes: ax = event.inaxes # the axes instance if 'AX1' in ax.get_label(): # Mouse is in subplot 1. xinf2 = np.int(event.xdata - zoom1) xsup2 = np.int(event.xdata + zoom1) yinf2 = np.int(event.ydata - zoom1) ysup2 = np.int(event.ydata + zoom1) ax2data = self.data[yinf2:ysup2, xinf2:xsup2] self.plt2.set_data(ax2data) self.ax2.figure.canvas.draw() -- Un clavier azerty en vaut deux ---------------------------------------------------------- Éric Depagne

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Legend labels and placement ignored?
by Akkana Peck Feb. 23, 2018

Feb. 23, 2018

Hi -- I'm having a problem with the legend on one of two subplots. For each curve plotted on each subplot, I set label="something", and then I set subplot.legend(position). This works for ax2, but for ax1 it's ignored. I asked on #matplotlib on Freenode and was advised it looked like a bug and that I should report it. So I did, https://github.com/matplotlib/matplotlib/issues/10576 but I thought I'd ask here too, to see if I'm doing something wrong in the way I specify my legends. I pared the example program down to this: ======= import matplotlib.pyplot as plt from matplotlib import gridspec import numpy as np def plot_planet(): tde = np.array([-23.029638, -22.953653, -22.871279, -22.782548, -22.687498, -22.586167, -22.478597, -22.364832, -22.244918, -22.118904, -21.986842]) obliq_ra = [-3.67878, -3.97686, -4.27044, -4.55928, -4.84302, -5.12142, -5.39412, -5.66088, -5.92146, -6.17544, -6.42264] eccen_ra = [ 0.40722, 0.27366, 0.14028, 0.0072, -0.12558, -0.25788, -0.3897, -0.52098, -0.6516, -0.78162, -0.91086] true_ra = [-3.27156, -3.7032, -4.13016, -4.55208, -4.9686, -5.3793, -5.78382, -6.18186, -6.57306, -6.95706, -7.3335 ] fig = plt.figure(figsize=(12, 8)) # width, height in inches gs = gridspec.GridSpec(1, 2, width_ratios=[2.5, 1]) # Plot equations of time: ax1 = fig.add_subplot(gs[0]) ax1.plot(obliq_ra, label="obliquity", color="lightblue") ax1.plot(eccen_ra, label="eccentricity", color="pink") ax1.plot(true_ra, label="Eqn of Time", color="black") ax1.set_title("Equation of Time") ax1.legend("upper left") # Plot the analemma: ax2 = fig.add_subplot(gs[-1]) ax2.plot(obliq_ra, tde, label="obliquity", color="lightblue") ax2.plot(eccen_ra, tde, label="eccentricity", color="pink") ax2.plot(true_ra, tde, label="analemma", color="black") ax2.set_title("Analemma") ax2.legend(loc="upper right") plt.show() if __name__ == '__main__': plot_planet() ======= Here's what I see: http://shallowsky.com/tmp/mpl-legend.jpg Note that the left subplot (ax1) has the legend in the upper right even though I specified upper left, and that the labels are mysteriously u, p, and p -- I can't figure out where those labels are coming from but they're clearly not the ones I specified. Any idea how I could fix this? Thanks! ...Akkana

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TypeError: float() argument must be a string or a number
by tia Feb. 19, 2018

Feb. 19, 2018

I am trying to get sensor data from Ubidots and plot them in a graph using Matplotlib. The graph can then be displayed on a web server via Flask. I am getting the following error when I run the codes: TypeError: float() argument must be a string or a number Matplotlib-Flask.py from flask import Flask, request, render_template from datetime import datetime from ubidots import ApiClient import matplotlib.pyplot as plt import matplotlib.dates as mdates import matplotlib.animation as animation from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas from matplotlib.figure import Figure import io app = Flask(__name__) //get the latest value of the ldr sensor from Ubidots def get_records(): api = ApiClient(token='XXXXXXXXXXXXXXXXXXXXXXX') my_variable = api.get_variable('XXXXXXXXXXXXXXXXXXXX') ldr = my_variable.get_values(1) return ldr //get the latest timestamp from Ubidots def get_times(): api = ApiClient(token='XXXXXXXXXXXXXXXXXXXXXXXX') variable = api.get_variable('XXXXXXXXXXXXXXXXXXXXXX') value = variable.get_values(1)[0] timestamp = value.get('timestamp') global t t= mdates.epoch2num(timestamp) return t //render the graph with x and y values of time and sensor values respectively and send to Flask @app.route('/', methods=['POST']) def my_form_post(): ldr= get_records() time= get_time() templateData = { 'ldr' : ldr, 'time' : t } return render_template('main.html', **templateData) //Plotting the graph using Matplotlib @app.route('/') def plot_temp(): ldr= get_records() ys = ldr fig = Figure() axis = fig.add_subplot(1,1,1) axis.set_title("Light Intensity") axis.set_xlabel("Time") axis.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M:%S')) axis.grid(True) time= get_times() xs = time axis.plot(xs,ys) canvas = FigureCanvas(fig) output = io.BytesIO() canvas.print_png(output) response = make_response(output.getvalue()) response.mimetype = 'image/png' ani= animation.FuncAnimation(fig, animate, interval=3000) return response if __name__ == "__main__": app.run(host='0.0.0.0', port=80, debug=True) I used the following reference links in case that helps: Ubidots timestamp: http://community.ubidots.com/t/convert-timestamp-on-json/473/2 Ubidots Python API: https://github.com/ubidots/ubidots-python Flask: http://www.mattrichardson.com/Raspberry-Pi-Flask/index.html Matplotlib graph using Flask: http://www.instructables.com/id/From-Data-to-Graph-a-Web-Jorney-With-Flask-… -- Sent from: http://matplotlib.1069221.n5.nabble.com/matplotlib-users-f3.html

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TypeError: float() argument must be a string or a number
by tia Feb. 18, 2018

Feb. 18, 2018

I am trying to get sensor data from Ubidots and plot them in a graph using Matplotlib. The graph can then be displayed on a web server via Flask. I am getting the following error when I run the codes: TypeError: float() argument must be a string or a number I think I have formatted the timestamp well and I checked questions related to that but I don't know what's wrong with the codes. This may seem like a duplicate of my previous [question][1] but this is another error with updated codes so I thought I should post it as a new question. Matplotlib-Flask.py from flask import Flask, request, render_template from datetime import datetime from ubidots import ApiClient import matplotlib.pyplot as plt import matplotlib.dates as mdates import matplotlib.animation as animation from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas from matplotlib.figure import Figure import io app = Flask(__name__) //get the latest value of the ldr sensor from Ubidots def get_records(): api = ApiClient(token='XXXXXXXXXXXXXXXXXXXXXXX') my_variable = api.get_variable('XXXXXXXXXXXXXXXXXXXX') ldr = my_variable.get_values(1) return ldr //get the latest timestamp from Ubidots def get_times(): api = ApiClient(token='XXXXXXXXXXXXXXXXXXXXXXXX') variable = api.get_variable('XXXXXXXXXXXXXXXXXXXXXX') value = variable.get_values(1)[0] timestamp = value.get('timestamp') global t t= mdates.epoch2num(timestamp) return t //render the graph with x and y values of time and sensor values respectively and send to Flask @app.route('/', methods=['POST']) def my_form_post(): ldr= get_records() time= get_time() templateData = { 'ldr' : ldr, 'time' : t } return render_template('main.html', **templateData) //Plotting the graph using Matplotlib @app.route('/') def plot_temp(): ldr= get_records() ys = ldr fig = Figure() axis = fig.add_subplot(1,1,1) axis.set_title("Light Intensity") axis.set_xlabel("Time") axis.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M:%S')) axis.grid(True) time= get_times() xs = time axis.plot(xs,ys) canvas = FigureCanvas(fig) output = io.BytesIO() canvas.print_png(output) response = make_response(output.getvalue()) response.mimetype = 'image/png' ani= animation.FuncAnimation(fig, animate, interval=3000) return response if __name__ == "__main__": app.run(host='0.0.0.0', port=80, debug=True) main.html: <!DOCTYPE html> <head> <title>{{ title }}</title> </head> <body> Hello, World! The date and time on the server is: {{ time }} </> </body> </html> I used the following reference links in case that helps: Ubidots timestamp: http://community.ubidots.com/t/convert-timestamp-on-json/473/2 Ubidots Python API: https://github.com/ubidots/ubidots-python Flask: http://www.mattrichardson.com/Raspberry-Pi-Flask/index.html Matplotlib graph using Flask: http://www.instructables.com/id/From-Data-to-Graph-a-Web-Jorney-With-Flask-… [1]: https://stackoverflow.com/questions/48849227/matplotlib-getting-valueerror-… -- Sent from: http://matplotlib.1069221.n5.nabble.com/matplotlib-users-f3.html

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Add multiplier to logscale colorer
by Nunzio Losacco Feb. 15, 2018

Feb. 15, 2018

Hi all, I am producing a contour plot with a lognormalized colorbar. If the levels are set to numpy.logspace(expmin,expmax,num) * mul the colorbar labels disappear. I would like them to be “mul x 10^exp “ I have been playing a lot with formatters but I didn’t manage to obtain what I want. Any help? N ***************************************************************** Dr. Nunzio Losacco (PhD, MEng, MSc, DIC) PostDoctoral Fellow University of Rome "Tor Vergata" Department of Civil Engineering and Computer Science Via del Politecnico, 1 - 00133 - Roma Italy +39 0672597062 *****************************************************************

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[ANN] Matplotlib v2.2.0rc1
by Thomas Caswell Feb. 14, 2018

Feb. 14, 2018

Folks, We are happy to release Matplotlib v2.2.0rc1! This is a feature release which includes new functionality (along with many bug-fixes). One of the hi-lights of this release is a constrained layout manager, please see https://matplotlib.org/devdocs/users/whats_new.html for details. API changes are at https://matplotlib.org/devdocs/api/api_changes.html The rc can be installed via pip pip install --pre matplotlib or via conda from conda-forge conda install -c conda-forge/label/rc matplotlib -c conda-forge The goal is to do 2.2.0 final around Mar. 2, please test these out and report bugs this week and next! mpl2.2 will be the last feature release in the Matplotlib 2.x series and the last feature release of Matplotlib to support python 2.7 and intend to provide bug fixes to 2.2 until 2020. We are looking for someone to take the lead on maintaining the 2.2.x branch, if you are interested please reach out! The next feature release after 2.2 will be 3.0 scheduled for July-August 2018. Thank you everyone (100+) who contributed to this release! Tom

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SciPy 2018 - one week left for submissions
by Paul Ivanov Feb. 8, 2018

Feb. 8, 2018

SciPy 2018, the 17th annual Scientific Computing with Python conference, will be held July 9-15, 2018 in Austin, Texas. The annual SciPyConference brings together over 700 participants from industry, academia, and government to showcase their latest projects, learn from skilled users and developers, and collaborate on code development. The call for abstracts for SciPy 2018 for talks, posters and tutorials is now open. The new extended deadline for submissions is February 15, 2018. Conference Website: https://scipy2018.scipy.org Submission Website: https://easychair.org/conferences/?conf=scipy2018 *July 9-15, 2018 | Austin, Texas * - *Tutorials:* July 9-10, 2018 - *Conference (Talks and Posters):* July 11-13, 2018 - *Sprints: *July 14-15, 2018 In addition to the general track, this year will have specialized tracks focused on: - Data Visualization - Reproducibility and Software Sustainability *Mini Symposia* · Astronomy · Biology and Bioinformatics · Data Science · Earth, Ocean and Geo Science · Image Processing · Language Interoperability · Library Science and Digital Humanities · Machine Learning · Materials Science · Political and Social Sciences There will also be a SciPy Tools Plenary Session each day with 2 to 5 minute updates on tools and libraries. *Tutorials (July 9-10, 2018)* Tutorials should be focused on covering a well-defined topic in a hands-on manner. We are looking for awesome techniques or packages, helping new or advanced Python programmers develop better or faster scientific applications. We encourage submissions to be designed to allow at least 50% of the time for hands-on exercises even if this means the subject matter needs to be limited. Tutorials will be 4 hours in duration. In your tutorial application, you can indicate what prerequisite skills and knowledge will be needed for your tutorial, and the approximate expected level of knowledge of your students (i.e., beginner, intermediate, advanced). Instructors of accepted tutorials will receive a stipend.

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