Re: [Matplotlib-users] How to plot straight lines on polar plots
On Fri, Jan 30, 2009 at 12:28 AM, jamesf0 jame...@utas.edu.au wrote: Sorry, I have done that change, and get these errors: Traceback (most recent call last): File test7.py, line 36, in module ax=fig.add_subplot(111, polar=True, resolution=1) File /usr/lib/python2.5/site-packages/matplotlib/figure.py, line 676, in add_subplot a = subplot_class_factory(projection_class)(self, *args, **kwargs) File /usr/lib/python2.5/site-packages/matplotlib/axes.py, line 6823, in __init__ self._axes_class.__init__(self, fig, self.figbox, **kwargs) File /usr/lib/python2.5/site-packages/matplotlib/projections/polar.py, line 171, in __init__ Axes.__init__(self, *args, **kwargs) File /usr/lib/python2.5/site-packages/matplotlib/axes.py, line 537, in __init__ if len(kwargs): martist.setp(self, **kwargs) File /usr/lib/python2.5/site-packages/matplotlib/artist.py, line 894, in setp func = getattr(o,funcName) AttributeError: 'PolarAxesSubplot' object has no attribute 'set_resolution' What version of mpl are you using? This should be fixed for releases = 0.98.4 JDH -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plot only inside a disc
[Christophe] Thanks, your example works but what I must do so to plot for example y=cos x ? I'm a very beginner. line, = ax.plot(x, np.cos(x)) patch = patches.Circle((300,300), radius=100) line.set_clip_path(patch) Everything in the matplotlib figure is an Artist (lines, images, text, rectangles) and you can set the clippath of any artist. See http://matplotlib.sourceforge.net/users/artists.html http://matplotlib.sourceforge.net/api/artist_api.html JDH This is a very timely question for me. I'm needing to do something very similar, but I need to overlay a semi-transparent rectangle with a hole cut out of it. So, I'm making a rectangular patch, making a circular patch, setting the circular patch as the clip region for the rectangular patch, and then adding the clipped patch to the plot. However, I seem to be having trouble with the coordinate system, as there is no clipping on the rectangle. My test code looks like this: import numpy as np import matplotlib.pyplot as plt import matplotlib.path as path import matplotlib.patches as patches fig = plt.figure() ax = fig.add_subplot(111) x = np.arange(-50,50,0.1) line, = ax.plot(x, np.cos(x)*50) r=patches.Rectangle((-10,-10), 20, 20, fc=(0.5,0.5,0.5,0.9)) r.set_zorder(100) # shouldn't one of these work? # Plot coordinate system cutout = patches.Circle((0,0), radius=10) # Window coordinate system #~ cutout = patches.Circle((300,300), radius=50) r.set_clip_path(cutout) ax.add_patch(r) plt.show() -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] contour coordinates
Hello again, I finally found the command I was looking for. It is the to_polygons(). Here is what worked : # make a LineCollection of contours col=contour(X,Y,Z,LevelsNumber).collections for i in np.arange(0,LevelsNumber,1): polygoni=col[i].get_paths()[0].to_polygons()[0] print polygoni All the vertices in each collections are extracted to the polygoni. Thanks again to Jeff and Patrick ! By the way, I found out that I do not actually need this procedure to achieve may goal which was to make a contour plot in ternary coordinates. Eli On Tue, Jan 27, 2009 at 11:08 PM, Patrick Marsh patrickmars...@gmail.comwrote: On Tue, Jan 27, 2009 at 7:16 PM, Eli Brosh ebro...@gmail.com wrote: Many thanks to Jeff and to Patric ! I will try to work along the line suggested by Jeff. Patric, please send me your code. I hope to learn from it. Thanks again, Eli Here is a template that can be used. I use this for meteorological models, but should work with any gridded file. import numpy as np from mpl_toolkits.basemap import Basemap f = (some gridded file) X = np.array(grab longitudes from f) Y = np.array(grab latitudes from f) field = np.array(grab field to be contoured from f) map = Basemap(make a Basemap call here) level = np.arange(minval, maxval, interval) col = map.contour(X, Y, field, level).collections for vertex in col[i].get_paths():# GET THE PATHS FOR THE EACH CONTOUR BY LOOPING THROUGH CONTOURS for vertex in xy.vertices: # ITERATE OVER THE PATH OBJECTS x, y = map(vertex[0],vertex[1],inverse=True) # vertex[0] and now 'x' is the longitude of the vertex and vertex[1] and now 'y' is the latitude of the vertex Let me know how this works. -Patrick On Tue, Jan 27, 2009 at 7:09 PM, Patrick Marsh patrickmars...@gmail.com wrote: On Tue, Jan 27, 2009 at 5:33 PM, Jeff Whitaker jsw...@fastmail.fm wrote: Eli Brosh wrote: Hello, I am trying to extract the coordinates of contour lines. I tried the following: cs = *contour*(Z) for lev, col in zip(cs.levels, cs.collections): s = col._segments that I found in a previous post (title contouring, by Jose Gómez-Dans-2 http://www.nabble.com/user/UserProfile.jtp?user=30071 Nov 30, 2007; 07:47am ) . I hoped that s will be a list of numpy arrays, each containing the (x,y) vertices defining a contour line at level lev. However, I got an error message: AttributeError: 'LineCollection' object has no attribute '_segments' How is it possible to get coordinates of the contours, similar to the MATLAB command [C,H] = *CONTOUR*(...) where the result in C is the coordinates of the contours. A similar question appeared in a post contour data (by Albert Swart http://www.nabble.com/user/UserProfile.jtp?user=382945 May 17, 2006; 09:42am) but I could not understand the answer. Is it possible to get more specific directions with a simple example ? Thanks Eli Eli: Calling get_paths() on each line collection in CS.collections will return a list of Path objects. From the Path objects, you can get a Nx2 array of vertices from the vertices attribute. There are no examples that I know of, but if you get it to do what you want to do, it would be great if you could contribute an example. As you noted, this question has come up several times before. -Jeff -- Jeffrey S. Whitaker Phone : (303)497-6313 Meteorologist FAX: (303)497-6449 NOAA/OAR/PSD R/PSD1Email : jeffrey.s.whita...@noaa.gov 325 BroadwayOffice : Skaggs Research Cntr 1D-113 Boulder, CO, USA 80303-3328 Web: http://tinyurl.com/5telg -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users I'm not sure if this is entirely what you (Eli) are looking for, but I have code that will contour model data on a map and then extract the lat,lon pairs of all the vertices. If this is what you are looking for, I'm happy to share what I've done. -Patrick -- Patrick Marsh Graduate Research Assistant School of Meteorology University of Oklahoma http://www.patricktmarsh.com -- Patrick Marsh Graduate Research Assistant School of Meteorology University of Oklahoma http://www.patricktmarsh.com -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story.
Re: [Matplotlib-users] Plot only inside a disc
On Fri, Jan 30, 2009 at 8:54 AM, andy.hens...@gtri.gatech.edu wrote: This is a very timely question for me. I'm needing to do something very similar, but I need to overlay a semi-transparent rectangle with a hole cut out of it. So, I'm making a rectangular patch, making a circular patch, setting the circular patch as the clip region for the rectangular patch, and then adding the clipped patch to the plot. However, I seem to be having trouble with the coordinate system, as there is no clipping on the rectangle. My test code looks like this: r.set_clip_path(cutout) ax.add_patch(r) plt.show() The problem is that the add_patch command is setting the clippath to the axes bounding box. I just committed a patch on the branch and trunk which only sets the clippath to the default if it is not already set. If you don't have access to svn, just make the call to r.set_clip_path *after* you call ax.add_patch. JDH -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plot only inside a disc
On Fri, Jan 30, 2009 at 10:27 AM, andy.hens...@gtri.gatech.edu wrote: Hmm ... this doesn't quite give me what I'm looking for. When I do that, I get a semitransparent circle that is clipped to a rectangle. What I need is a semi-transparent rectangle (with a hole cut out of the middle) that overlays the plot. The attached graphic demonstrates the concept. It sounds like what you want is a complex path and may not need to muck with clipping at all. Take a look at http://matplotlib.sourceforge.net/examples/api/donut_demo.html -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plot only inside a disc
-Original Message- From: John Hunter [mailto:jdh2...@gmail.com] Sent: Friday, January 30, 2009 11:29 AM To: Henshaw, Andy Cc: matplotlib-users@lists.sourceforge.net Subject: Re: [Matplotlib-users] Plot only inside a disc On Fri, Jan 30, 2009 at 10:27 AM, andy.hens...@gtri.gatech.edu wrote: Hmm ... this doesn't quite give me what I'm looking for. When I do that, I get a semitransparent circle that is clipped to a rectangle. What I need is a semi-transparent rectangle (with a hole cut out of the middle) that overlays the plot. The attached graphic demonstrates the concept. It sounds like what you want is a complex path and may not need to muck with clipping at all. Take a look at http://matplotlib.sourceforge.net/examples/api/donut_demo.html Okay, although I wish the clipping was working as I expected, as it looks like it would have been **quite a bit** cleaner. It looks like your svn patch would enable me to do what I want with patches, wouldn't you agree? -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plot only inside a disc
-Original Message- From: andy.hens...@gtri.gatech.edu [mailto:andy.hens...@gtri.gatech.edu] Sent: Friday, January 30, 2009 11:46 AM To: jdh2...@gmail.com Cc: matplotlib-users@lists.sourceforge.net Subject: Re: [Matplotlib-users] Plot only inside a disc -Original Message- From: John Hunter [mailto:jdh2...@gmail.com] Sent: Friday, January 30, 2009 11:29 AM To: Henshaw, Andy Cc: matplotlib-users@lists.sourceforge.net Subject: Re: [Matplotlib-users] Plot only inside a disc On Fri, Jan 30, 2009 at 10:27 AM, andy.hens...@gtri.gatech.edu wrote: Hmm ... this doesn't quite give me what I'm looking for. When I do that, I get a semitransparent circle that is clipped to a rectangle. What I need is a semi-transparent rectangle (with a hole cut out of the middle) that overlays the plot. The attached graphic demonstrates the concept. It sounds like what you want is a complex path and may not need to muck with clipping at all. Take a look at http://matplotlib.sourceforge.net/examples/api/donut_demo.html Thanks, that is working quite well, now. -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] [matplotlib-devel] What would you like to see in a book about Matplotlib?
Note: Posted to matplotlib-devel and debian-science. Sandro, Firstly, good luck with the book. The sort of book I'd buy would explain how to use the combination of matplotlib/ipython/scipy/numpy to analyse data. - what are you using matplotlib for? I want to use matplotlib/ipython/numpy/scipy for analysis of experimental data - plotting and fitting models to it. Also perhaps simulation of the data. I have also wanted to use matplotlib to plot data as it was acquired - see below. I've not really used matplotlib in anger - but am likely to do so in the future (and it would have been useful during my PhD had it been around then). - what are the things you like the most of matplotlib, that you want to give emphasis to? And why? Quality plots. The ability to add TeX labels. I've been keeping an eye on matplotlib for several years - it looks good. I really must spend some time exploring it. - what are the (basic) things that, when you were beginning to use matplotlib, you wanted to see grouped up but couldn't find? - what would you like to see in a book about matplotlib? Start off by reading data from a file, plotting it and fitting a function to that data. Often, several scans are in the same data file. An elegant solution to reading data something like this example would be useful. # Scan: 1 # Time: 18:00 # Temperature: 21 # t data 1 12 2 33 3 14 4 40 5 60 # Scan: 2 # Time: 18:02 # Temperature: 30 # t data 1 22 2 33 3 44 4 55 And so on. Fitting a function to several data sets - with some of the parameters fitted to both sets of data and some not would be useful. - what are some those advanced feature that made you yell WOW!! ? - what are the things you'd like to explore of matplotlib and never had time to do? Plotting with related scales Sometimes it is useful to plot related scales on x1 and x2 axes. I've come across this several times in different contexts. In its simplest form, there is a linear relationship between the axes. In a mechanical test, you might want extension on the x1 axis and strain on the x2 axis (for example). Sometimes there is not a linear relationship. For example you might want to plot frequency (or photon energy) on x1 and wavelength on x2. An even more complex example is a Hall-Petch plot: (Yield Stress) = k/sqrt(Grain Size) So plotting 1/Sqrt(Grain Size) on the X1 axis gives a linear plot, but it would be useful to plot the grain size on the X2 scale. ipython and emacs - Suppose I want to write a script to analyse some data (perhaps I want a record of what I've done, or perhaps I'd like to perform the same analysis on several data sets). I'd probably do so in emacs - but it is useful to do some experimentation in ipython - tab completion is particularly useful. I feel there must be a good way to do my experimentation in ipython and save the important bits in emacs - but I've not sat down and worked out an efficient way of doing this. Data aqcuisition and experimental control: - Writing a simple application to acquire data - ideally from multiple sources and plot the data as it is acquired. In my case I wanted to combine mechanical with electrical tests. A couple of interesting articles by G Varoquaux are listed at http://wiki.debian.org/DebianScience/DataAcquisition This is perhaps beyond the scope of the book, but it has come up on the mailing lists a couple of times. The ideal application would have a gui for simple use, but a command line (probably ipython) for more more complex use - perhaps performing a series of tests under different conditions. Some discussion of plotting non gridded 2d data should also be in there. Your suggestions are really appreciated :) And wish me good luck! I don't think it is the thrust of your book, but another book I was looking for is A cookbook of Numerical simulations of classic physics/engineering problems. For use by physicists/engineers who don't want to rewrite things from scratch. Good luck. Chris -- This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
