Mailman 3 January 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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Replacing deprecated use of pyplot.subplot
by Rory Yorke Feb. 3, 2018

Feb. 3, 2018

Hi, I'm a contributor to the Python Control Systems Library [1], which uses Matplotlib for plotting. We recently noticed deprecation warnings due to how we use pyplot.subplot. We use it in the Matlab manner of either getting a handle to an existing axis, or creating one if no suitable axis exists. The warning is MatplotlibDeprecationWarning: Adding an axes using the same arguments as a previous axes currently reuses the earlier instance. In a future version, a new instance will always be created and returned. Meanwhile, this warning can be suppressed, and the future behavior ensured, by passing a unique label to each axes instance. For example, to plot the frequency response a linear dynamical system (AKA Bode plot of the system), the relevant function could be simplified to: def bode_plot(g): freq, mag, phase = freq_resp(g) subplot(211) semilogx(freq, 20*log10(mag)) subplot(212) semilogx(freq, phase) We've replaced that with code like this: def bode_plot(g): freq, mag, phase = freq_resp(g) ax_mag = None ax_phase = None for ax in gcf.axes(): if ax.get_label() == 'control-bode-magnitude': ax_mag = ax elif ax.get_label() == 'control-bode-phase': ax_phase = ax if ax_mag is None or ax_phase is None: clf() ax_mag = subplot(211, label = 'control-bode-magnitude') ax_phase = subplot(212, label = 'control-bode-phase) ax_mag.semilogx(freq, 20*log10(mag)) ax_phase.semilogx(freq, phase) This means that calls like bode_plot(g) bode_plot(h) will show the response of g and h on the same figure. Is this method of using labels to check for existing axes reasonable? Is there a better way? Actual code exhibiting warnings at [2]; new code at [3]. The latter link is to an as-yet unmerged branch, and may disappear. Thanks, Rory [1] https://github.com/python-control/python-control [2] https://github.com/python-control/python-control/blob/af8d4ee39dfa574c2b3b3… [3] https://github.com/murrayrm/python-control/blob/dc1820a4e64d73937c7de8df078…

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pick events don't work with twiny
by Neal Becker Jan. 31, 2018

Jan. 31, 2018

I find that pick events are fine until I add twiny. In that case, nothing happens when clicking. THe code outline is like: fig, ax = plt.subplots() ax2 = ax.twiny() ax.semilogy(...) fig.canvas.mpl_connect('pick_event', onpick) ax2_xaxis = np.linspace (*ax.get_xlim(), endpoint=True,)/conversion ax2.semilogy (ax2_xaxis, np.ones (len(ax2_xaxis)) * 1e-3, alpha=0) ax2.set_xlabel(...) ... removing all the lines about ax2 will restore pick function.

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Subplots, axes labels and mouse events.
by Éric Depagne Jan. 21, 2018

Jan. 21, 2018

Hi all, I have a figure which consists of three subplots, which I have defined as follows: gs = gridspec.GridSpec(2, 2) self.ax1 = plt.subplot(gs[0:, 0]) self.ax2 = plt.subplot(gs[1]) self.ax3 = plt.subplot(gs[3]) self.ax1.imshow(self.data, vmin=self.dataminzs, vmax=self.datamaxzs) self.ax1.figure.canvas.mpl_connect('motion_notify_event', self._on_move) The _on_move() callback is (currently) defined as: def _on_move(self, event): if event.inaxes: ax = event.inaxes # the axes instance print('data coords %s %f %f' % (ax, event.xdata, event.ydata)) I want that when I hover the mouse over ax1 then ax2 and ax3 show the part of ax1 which is under the cursor, with 2 different levels of zooms. I want to limit the region where the _on_move() is called to ax1 and I struggle to get what I want. I thought that calling self.ax1.figure.canvas.mpl_connect('motion_notify_event', self._on_move) would limit the area of my figure where the mouse event are caught to ax1, but it's not the case. I see that even.inaxes is picking that I'm on different part of the figure, the print('data coords %s %f %f' % (ax, event.xdata, event.ydata)) shows different values for ax depending on where the mouse is over the figure So I thought that I might be checking the attributes of event.inaxes to make sure I do what I need to do only when the mouse is over ax1, but it seems that all the attributes of the Axes are not passed to the _on_move() callback. self.ax1.set_label('AX1') sets the ax1 label as expected, but if I test the event.inaxes.properties() in my _on_move(), then the label attribute is not set anymore. Is there a way to make sure the _on_move() is fired only on a specific area of my figure? Any help appreciated. Thanks. Éric. -- Un clavier azerty en vaut deux ---------------------------------------------------------- Éric Depagne

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fig.legend method and axes.legend method behaves differently?
by Henry east Jan. 12, 2018

Jan. 12, 2018

Hi, I tried to make a plot with two subplots but only one legend since the two subplots express the same set of information. I put the legend outside of the two subplots for better interpretation. I have found that by using fig.legend instead of the ax.legend method. In the saved plot, the legend box are just cut off. I tried to fix this by using bbox_extra_artists argument in the savefig method, following the instruction here<https://stackoverflow.com/questions/10101700/moving-matplotlib-legend-outsi…>. But it does not work. The following code illustrate the problem, import matplotlib.pyplot as plt import numpy as np import matplotlib as mpl x = np.arange(-5, 5, 0.1) y1 = np.sin(x) y2 = np.cos(x) y3 = np.sin(2*x) y4 = np.cos(2*x) fig, (ax1, ax2) = plt.subplots(ncols=1, nrows=2, figsize=(10, 6)) ax1.plot(x, y1, label='sin') ax1.plot(x, y2, label='cos') ax2.plot(x, y3, label='sin') ax2.plot(x, y4, label='cos') handles, labels = ax1.get_legend_handles_labels() # legend = fig.legend(handles, labels, loc='lower left', ncol=2, frameon=False, # bbox_to_anchor=(0.12, 0.88)) # plt.savefig('test.jpg', bbox_extra_artists=(legend,), bbox_inches='tight') legend = ax1.legend(handles, labels, ncol=2, frameon=False, loc='lower left', bbox_to_anchor=(-0.01, 1.0)) plt.savefig('test.jpg', bbox_inches='tight') If I use the above code, the generated image is fine. But if I use the commented code instead, the legend is gone in the generated image.

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Project to work on
by KUSHAL BORKAR Jan. 12, 2018

Jan. 12, 2018

Greetings all, My name is Kushal Borkar. I'm from India and currently I'm pursuing Bachelor's Degree in Electronics and Communication. I have basic knowledge of C++ and Python. I would love to contribute to and learn from 'Matplotlib'. I have done a course on Digital Image Processing and worked on Matplotlib in this course. So, I kindly request to suggest me a project in this field to work upon before the application starts. With Regards, Kushal Borkar.

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Re: [Matplotlib-users] reset color cycler?
by Saito Kotaro (PSI) Jan. 11, 2018

Jan. 11, 2018

Backend doesn’t matter in your case. I recommend to apply 'Colors from color cycle’ method in the SO answer. The idea is that, first, you get a list of colors from your color cycle before making a pdf page. Then you plot your data with color keyword, like plot(x, y, color=color_list_from_colorcycle[i]) with an index number ‘i’ incremented after each plot, save a pdf page, reset the index ‘i’ to zero, repeat the procedure whatever times you want. It’s not elegant at all but I’m sure it solves the problem. If first ten colors in your color cycle is enough for you, then ‘CN notation’ method is also applicable. (matplotlib 2 is required for this method) Best, Kotaro > 2018/01/11 19:08、Neal Becker <ndbecker2(a)gmail.com>のメール: > > I'm using PdfPages to produces multiple plots. At the start of each page I reset the color cycle. > > On Thu, Jan 11, 2018 at 12:55 PM Saito Kotaro (PSI) <kotaro.saito(a)psi.ch> wrote: > Hi Neal, > > I’m not sure about your purpose for resetting the colour cycle, but this answer might be helpful. > > https://stackoverflow.com/a/47773515/9131000 > > Best regards, > > Kotaro >

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Re: [Matplotlib-users] reset color cycler?
by Saito Kotaro (PSI) Jan. 11, 2018

Jan. 11, 2018

Hi Neal, I’m not sure about your purpose for resetting the colour cycle, but this answer might be helpful. https://stackoverflow.com/a/47773515/9131000 Best regards, Kotaro

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