Mailman 3 September 2015 - Matplotlib-users

Matplotlib 1.4.2 / 1.4.3 doesn't install from source
by fbarbuto Oct. 13, 2015

Oct. 13, 2015

Hello, I have Matplotlib 1.3.1 installed on my Ubuntu 14.04 system and thought it was time to upgrade to 1.4.2. I never get the latest version for compatibility reasons (some packages that use Matplotlib might stop working). I then downloaded the tarball, uncompressed its contents into a folder and executed "sudo python setup.py build". However, I got the following error (last few lines only): c++ -pthread -shared -Wl,-O1 -Wl,-Bsymbolic-functions -Wl,-Bsymbolic-functions -Wl,-z,relro -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -D_FORTIFY_SOURCE=2 -g -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security build/temp.linux-x86_64-2.7/src/ft2font.o build/temp.linux-x86_64-2.7/src/mplutils.o build/temp.linux-x86_64-2.7/extern/CXX/cxxsupport.o build/temp.linux-x86_64-2.7/extern/CXX/cxx_extensions.o build/temp.linux-x86_64-2.7/extern/CXX/IndirectPythonInterface.o build/temp.linux-x86_64-2.7/extern/CXX/cxxextensions.o -L/usr/local/lib -L/usr/local/lib64 -lfreetype -lstdc++ -lm -o build/lib.linux-x86_64-2.7/matplotlib/ft2font.so /usr/bin/ld: /usr/local/lib64/libstdc++.a(si_class_type_info.o): relocation R_X86_64_32S against `_ZTVN10__cxxabiv120__si_class_type_infoE' can not be used when making a shared object; recompile with -fPIC /usr/local/lib64/libstdc++.a: error adding symbols: Bad value collect2: error: ld returned 1 exit status error: command 'c++' failed with exit status 1 I then tried the same with Matplotlib 1.4.3 (why not?) and got the same results. What's going on here? Thanks so much for any help. Fausto -- View this message in context: http://matplotlib.1069221.n5.nabble.com/Matplotlib-1-4-2-1-4-3-doesn-t-inst… Sent from the matplotlib - users mailing list archive at Nabble.com.

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RuntimeError. LaTeX was not able to process the following string
by bsjun Oct. 12, 2015

Oct. 12, 2015

How can I fix this error? I'm using Cent OS.. I installed Latex by 'yum install tetex' -- View this message in context: http://matplotlib.1069221.n5.nabble.com/RuntimeError-LaTeX-was-not-able-to-… Sent from the matplotlib - users mailing list archive at Nabble.com.

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Problem : Combining mouse button events with pick events in a scatter plot
by joh Oct. 11, 2015

Oct. 11, 2015

Hello everybody, I am trying to combine mouse button events with a pick event in scatter plot. Different functionalities take place, based on the mouse button pressed each time. I want each functionality to be triggered with a combination of mouse buttons events and/or key press events. When the left mouse button is pressed matplotlib's Lasso widget is called and with the included points functionality 1 takes place. When Shift+LMB are pressed a Lasso is drawn and functionality 2 takes place with the included points. When Alt+LMB are pressed a Lasso is drawn and with the included points functionality 3 takes place. Last, but not least, when I press the RMB a pick event is triggered and the index of the selected point in the scatter plot is given. Since I added the pick event, the aforementioned functionalities work correctly until a pick event is triggered. When it is triggered it seems that the canvas gets locked and I can not use any other functionality. I don't get the index of the selected points and I do not get any errors. ----------------Code------------------------- import logging import matplotlib from matplotlib.widgets import Lasso from matplotlib.colors import colorConverter from matplotlib.collections import RegularPolyCollection from matplotlib import path import numpy as np import matplotlib.pyplot as plt from numpy.random import rand logger = logging.getLogger() logger.setLevel(logging.DEBUG) class Datum(object): colorin = colorConverter.to_rgba('red') colorShift = colorConverter.to_rgba('cyan') colorCtrl = colorConverter.to_rgba('pink') colorout = colorConverter.to_rgba('blue') def __init__(self, x, y, include=False): self.x = x self.y = y if include: self.color = self.colorin else: self.color = self.colorout class LassoManager(object): def __init__(self, ax, data): self.axes = ax self.canvas = ax.figure.canvas self.data = data self.Nxy = len(data) facecolors = [d.color for d in data] self.xys = [(d.x, d.y) for d in data] fig = ax.figure self.collection = RegularPolyCollection(fig.dpi, 6, sizes=(100,),facecolors=facecolors, offsets = self.xys, transOffset = ax.transData) ax.add_collection(self.collection) self.pick=self.canvas.mpl_connect('pick_event', self.onpick) self.cid = self.canvas.mpl_connect('button_press_event', self.onpress) self.keyPress = self.canvas.mpl_connect('key_press_event', self.onKeyPress) self.keyRelease = self.canvas.mpl_connect('key_release_event', self.onKeyRelease) self.lasso = None self.shiftKey = False self.ctrlKey = False def callback(self, verts): logging.debug('in LassoManager.callback(). Shift: %s, Ctrl: %s' % (self.shiftKey, self.ctrlKey)) facecolors = self.collection.get_facecolors() p = path.Path(verts) ind = p.contains_points(self.xys) for i in range(len(self.xys)): if ind[i]: if self.shiftKey: facecolors[i] = Datum.colorShift elif self.ctrlKey: facecolors[i] = Datum.colorCtrl else: facecolors[i] = Datum.colorin print self.xys[i] else: facecolors[i] = Datum.colorout self.canvas.draw_idle() self.canvas.widgetlock.release(self.lasso) del self.lasso def onpress(self, event): if self.canvas.widgetlock.locked(): return if event.inaxes is None: return self.lasso = Lasso(event.inaxes, (event.xdata, event.ydata), self.callback) # acquire a lock on the widget drawing self.canvas.widgetlock(self.lasso) def onKeyPress(self, event): logging.debug('in LassoManager.onKeyPress(). Event received: %s (key: %s)' % (event, event.key)) if event.key == 'alt': self.ctrlKey = True if event.key == 'shift': self.shiftKey = True def onKeyRelease(self, event): logging.debug('in LassoManager.onKeyRelease(). Event received: %s (key: %s)' % (event, event.key)) if event.key == 'alt': self.ctrlKey = False if event.key == 'shift': self.shiftKey = False def onpick(self,event): if event.mouseevent.button == 3: index = event.ind print('onpick3 scatter:', index) if __name__ == '__main__': data = [Datum(*xy) for xy in rand(100, 2)] ax = plt.axes(xlim=(0,1), ylim=(0,1), autoscale_on=False) lman = LassoManager(ax, data) plt.show() ------------------End of Code----------------------------- Any suggestions on what might be causing this malfunction? What am I doing wrong? -- View this message in context: http://matplotlib.1069221.n5.nabble.com/Problem-Combining-mouse-button-even… Sent from the matplotlib - users mailing list archive at Nabble.com.

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read a png image with alpha gives uncorrect colors
by PBrockmann Oct. 9, 2015

Oct. 9, 2015

Hi, I have encountered a problem with this simplified code where I produce a windrose with some alpha level. Then read this png image to check. Then discover that the colors are not correct. What is the mistake ? I am puzzled. I use matplotlib 1.4.3 The correct windrose with alpha colors <http://matplotlib.1069221.n5.nabble.com/file/n46131/windrose.png> The read png image. <http://matplotlib.1069221.n5.nabble.com/file/n46131/read.png> Regards Patrick -- View this message in context: http://matplotlib.1069221.n5.nabble.com/read-a-png-image-with-alpha-gives-u… Sent from the matplotlib - users mailing list archive at Nabble.com.

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Animating 3D quiver plot in 1.4.3?
by plottingberra Oct. 9, 2015

Oct. 9, 2015

Hello! I want to create a 3D animation that animates the trajectory of a flying object. The FuncAnimation object has been really helpful in doing so, but now I want to plot an arrow (using the Quiver class) depicting the acceleration vector at the object's position in its path. My key problem is that I only want exactly one arrow on the plot at a time. Currently I am able to create an animated trail of arrows, but I want to clear the arrows that were plotted before a certain time t. I know that there exists a method set_UVC that allows for this sort of data updating, but I cannot get it to work for the 3D case. Alternatively, I tried searching for a method that clears the entire quiver plot (inelegant, but should work for my loop), but was unsuccessful in finding one that works. I'd like to ask, then: 1. Is there a way of making set_UVC work for my 3D case? 2. What is the proper way to clear a quiver plot? Thank you so much! -- View this message in context: http://matplotlib.1069221.n5.nabble.com/Animating-3D-quiver-plot-in-1-4-3-t… Sent from the matplotlib - users mailing list archive at Nabble.com.

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meaning of parameters for scipy.spectial.pro_ang1
by Neal Becker Sept. 25, 2015

Sept. 25, 2015

I'm trying to compare: http://docs.scipy.org/doc/scipy/reference/generated/scipy.special.pro_ang1.… which lists 4 parameters: (m, n, c, x) with this reference: https://www.researchgate.net/publication/223606627_Prolate_spheroidal_wave_… which refers to 4 parameters (see section 2): The continuous time parameter t, the order,n, of the function, the interval on which the function is known, t0, and the bandwidth parameter c. The bandwidth parameter is given by c= t0Ω, (3) whereΩ is the finite bandwidth or cutoff frequency ofψn(t) of a given ordern. Unfortunately the scipy doc doesn't give a description of it's parameters or any reference.

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ANN: MPLslides - basic prensentations with matplotlib
by Till Stensitzki Sept. 22, 2015

Sept. 22, 2015

Hi, instead spending time actually making presentations my procrastinating actually lead to the development of a very basic presentation framework based on matplotlib. I know, that's the stuff everybody was waiting for :) https://github.com/Tillsten/MPLslides An example presentation can be found under: https://github.com/Tillsten/MPLslides/raw/master/example.pdf To my surprise i think it actually usable. Features: * native matplotlib support :) * cheap css-like copy for styling elements. * customizable layout * that includes animated plots! * text and enumerations! * thanks to matplotlib, a lot of output formats are supported. This is by no means a replacement for anything, but maybe someone will have with it. greetings Till

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matplotlib compilation and running issues
by Jason Snyder Sept. 17, 2015

Sept. 17, 2015

To who it may concern, I installed matplotlib on my computer and tried to run a program with the code below: import numpy as np import matplotlib.pyplot as plt x = np.linspace(0, 10) line, = plt.plot(x, np.sin(x), '--', linewidth=2) When I ran the program I could the below error output: [vrsops@am-linux-212 cpcharts]$ python line_demo_dash_control.py Traceback (most recent call last): File "line_demo_dash_control.py", line 12, in <module> line, = plt.plot(x, np.sin(x), '--', linewidth=2) File "/usr/lib64/python2.7/site-packages/matplotlib/pyplot.py", line 3092, in plot ax = gca() File "/usr/lib64/python2.7/site-packages/matplotlib/pyplot.py", line 828, in gca ax = gcf().gca(**kwargs) File "/usr/lib64/python2.7/site-packages/matplotlib/pyplot.py", line 462, in gcf return figure() File "/usr/lib64/python2.7/site-packages/matplotlib/pyplot.py", line 435, in figure **kwargs) File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_qt4agg.py", line 47, in new_figure_manager return new_figure_manager_given_figure(num, thisFig) File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_qt4agg.py", line 54, in new_figure_manager_given_figure canvas = FigureCanvasQTAgg(figure) File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_qt4agg.py", line 72, in __init__ FigureCanvasQT.__init__(self, figure) File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_qt4.py", line 68, in __init__ _create_qApp() File "/usr/lib64/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 138, in _create_qApp raise RuntimeError('Invalid DISPLAY variable') RuntimeError: Invalid DISPLAY variable What is causing these errors and how do I resolve this issue? Also echo $DISPLAY is blank. Thank you for your time. -Jason

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First release candidate for the 1.5.0 series
by Thomas Caswell Sept. 16, 2015

Sept. 16, 2015

Please give it a try! (linux64 conda builds are available on the tacaswell anaconda.org channel) https://github.com/matplotlib/matplotlib/releases/tag/v1.5.0rc1 This release contains many new features. The highlights include: - the object oriented API will now automatically re-draw the figure when working in the command line - automatic unpacking of labeled data into most plotting functions - arbitrary style cycling - four new perceptually linear color maps - mouse-over for pixel values with `imshow` - many new rcparams In addition there are significant improvements to `nbagg` and a complete overhaul of the c++ bindings to AGG. Please see the drafts of the [full whats new]( http://matplotlib.org/devdocs/users/whats_new.html#new-in-matplotlib-1-5) and [api changes]( http://matplotlib.org/devdocs/api/api_changes.html#changes-in-1-5-0)

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Vectorized version of text()
by Brendan Barnwell Sept. 14, 2015

Sept. 14, 2015

This is something that I constantly wish for and keep having to hack around when I remember there's nothing to do it. Or is there? Am I missing something? What I want is the ability to provide a vector of x, y, and text, so that *with a single call* I can display specified bits of text at a specified points. Currently text() only puts a single text at a single point, so to plot multiple texts you have to call it in a loop. This is especially annoying because, when you have everything in a pandas DataFrame, the points and text are often already aligned as separate columns. I'd like to be able to do pyplot.multitext(df.x, df.y, df.label) or whatever and just have it work. Better yet, just be able to pass an extra "pointlabel" argument directly to scatter, which would specify a sequence of labels, one for each point. The labels could then be turned off with some method on the scatter artist (and perhaps a shortcut pyplot method as well). I seem to recall there are some performance issues with plotting many different Text objects, but that doesn't seem reason enough in itself not to provide this, since lots of things can cause performance issues with large datasetrs. Does anyone else think this would be worth adding? -- Brendan Barnwell "Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail."

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