[Matplotlib-users] Is there interrest for an implementation of colour maps visualising small differences around 0
Hi I've created a python method for making a jet colour map which clearly shows small changes around a given point in the colour map, (i.e. the opposite of a diverging colour map http://www.sandia.gov/~kmorel/documents/ColorMaps/ ). This looks something like figure four on: http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=1828750 If this is something that is interesting for implementation in matplotlib, I would be happy to clean up my code and submit a patch with it? Kind regards Pål -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Animate on Mac O$
Hi Ryan, In matplotlib, drawing is done as part of the call to figure.draw(renderer). The MacOSX backend makes this call from the event loop callback (i.e., the drawRect function in src/_macosx.m). Outside of the event loop callback, the graphics context (CGContextRef on Macs) is undefined, and no drawing can take place. In the animations module, event_source is a timer that periodically calls _step, which calls _draw_next_frame, which calls _post_draw to do the blitting. But since the timer lives outside if the event loop, blitting will fail on Macs; there simply is no graphics context to draw to. The solution is to split the blitting into two parts: - A front-end blitting function that tells matplotlib to blit (this is the function called by the timer) - A back-end blitting function that does the actual blitting (as part of the call to figure.draw(renderer); the back-end blitting function is implemented in the backend). In a sense, this is the same as for the other graphics functions (e.g. there is a front-end plot function, and a back-end draw_path function). See the discussion here for more information: https://github.com/matplotlib/matplotlib/issues/531 (this discussion also went into other issues though). Best, -Michiel. On Thu, 3/13/14, Ryan May rma...@gmail.com wrote: Subject: Re: [Matplotlib-users] Animate on Mac O$ To: Michiel de Hoon mjldeh...@yahoo.com Cc: Christophe Bal projet...@gmail.com, Matplotlib matplotlib-users@lists.sourceforge.net Date: Thursday, March 13, 2014, 8:29 PM On Mar 13, 2014, at 17:55, Michiel de Hoon mjldeh...@yahoo.com wrote: The problems with animations on Mac are not so much related to the backend, but to the animations code itself. Animations with the MacOSX backend cannot be fixed without redesigning the animations module. Can you give me a better idea why you think so? I wrote the original and have a Mac now... Ryan -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Is there interrest for an implementation of colour maps visualising small differences around 0
Pål, Matplotlib already has a jet colormap and has moved away from using it as the default for the very reasons listed in the first paper you site. How is your jet colormap different? Can you provide a comparison with the existing colormap? Does it overcome the drawbacks listed in the Sandia Nat'l Labs paper? -paul On Fri, Mar 14, 2014 at 3:16 AM, Pål Gunnar Ellingsen paa...@gmail.comwrote: Hi I've created a python method for making a jet colour map which clearly shows small changes around a given point in the colour map, (i.e. the opposite of a diverging colour map http://www.sandia.gov/~kmorel/documents/ColorMaps/ ). This looks something like figure four on: http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=1828750 If this is something that is interesting for implementation in matplotlib, I would be happy to clean up my code and submit a patch with it? Kind regards Pål -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Is there interrest for an implementation of colour maps visualising small differences around 0
Hi Paul I'm aware that matplotlib has moved away from the jet map, which in most cases I would agree is a good thing. My map is not a replacement for the jet colourmap, or any other colourmap. My map is the inverse of the diverging colourmaps, seeking to enhance small changes around a certain part of the colourmap (normally the centre, but it can be set by the user). In order to show the difference I have generated four test plots. Since I don't want to fill your inbox with attachments, they can be found at http://sudodolphin.blogspot.no/2014/03/creating-colourmaps-enhancing-small.html with a description. Cheers Pål On 14 March 2014 15:13, Paul Hobson pmhob...@gmail.com wrote: Pål, Matplotlib already has a jet colormap and has moved away from using it as the default for the very reasons listed in the first paper you site. How is your jet colormap different? Can you provide a comparison with the existing colormap? Does it overcome the drawbacks listed in the Sandia Nat'l Labs paper? -paul On Fri, Mar 14, 2014 at 3:16 AM, Pål Gunnar Ellingsen paa...@gmail.comwrote: Hi I've created a python method for making a jet colour map which clearly shows small changes around a given point in the colour map, (i.e. the opposite of a diverging colour map http://www.sandia.gov/~kmorel/documents/ColorMaps/ ). This looks something like figure four on: http://biomedicaloptics.spiedigitallibrary.org/article.aspx?articleid=1828750 If this is something that is interesting for implementation in matplotlib, I would be happy to clean up my code and submit a patch with it? Kind regards Pål -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Example showing differences between Mac O$ and Windows use
I have used Anaconda with my students because it installs a standard environment on all platforms, it works very well and is easy to install. I have also tried to Enthought Canopy but swicthed to Anaconda because Anaconda was as simple to use, came with hfewer restrictions and in my experience also fewer bugs and problems than Canopy. Macorts also work very well, though. So that is a matter of taste, I guess. The upside to Anaconda is that I believe it runs the Qt4Agg backend by default for all platforms. Can anyone confirm this (I don't have access to a Mac at the moment)? On Thu 13 Mar 2014 09:29:38 PM CET, Sterling Smith wrote: +1 for macports (I haven't used the others.) On Mar 13, 2014, at 10:12AM, Felix Patzelt wrote: Are you sure that you want to use Python 3.3 on OSX 10.6??? Do you really still use 10.6? Do you want Python 3? I'm not sure on the current status, but many projects took quite a while to get ported over from Python 2. Furthermore, as often with free software, installation can be a bit tricky. It is certainly a very different experience than installing normal Mac applications. For a bit of context, most Linux distribution have some version of Python / Matplotlib in their respective package managers. These are easily installed if the particular package manager on your Linux offers the versions you want. Otherwise, you will have to do some work. OSX does not have an official package manager, but there are several inofficial options. I'm using http://www.macports.org which is slow because it installs its own private versions for everything, but it works very well. This is probably the easiest way to get all the open source stuff you want on your Mac and I use it a lot. Another popular and more lightweight package manager is homebrew, which relies more on the system libraries from Apple. The minimal installation instructions without a package manager seem to be these: https://github.com/rueckstiess/mtools/wiki/matplotlib-Installation-Guide If you're a real unix hacker, you can install everything from source. I did that before, and it takes a lot of time and in-depth knowledge. Finally, there are several pre-packaged distributions like https://www.enthought.com or https://store.continuum.io/cshop/anaconda/ (see http://penandpants.com/install-python/). They might come with a normal OSX installer. Maybe https://code.google.com/p/spyderlib/ does the trick for you? Anyway, these are just some suggestions. Maybe you want to start a separate thread on the mailing list about the best way to install matplotlib on a mac. Please note that I cannot comment in detail on any of the installation methods that I didn't use myself. Am 13.03.2014 um 17:36 schrieb Christophe Bal projet...@gmail.com: I've tested a more simpler Python code. from pylab import * plot([1,2,3]) show() This gives me a scary backend MacOSX version unknown. I've used the official DMG installer matplotlib-1.3.1-py3.3-python.org-macosx10.6.dmg. This seems to be a big problem. No ? $HOME=/Users/ matplotlib data path /Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/matplotlib/mpl-data loaded rc file /Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/site-packages/matplotlib/mpl-data/matplotlibrc matplotlib version 1.3.1 verbose.level helpful interactive is False platform is darwin CACHEDIR=/Users//.matplotlib Using fontManager instance from /Users//.matplotlib/fontList.py3k.cache backend MacOSX version unknown 2014-03-13 17:31 GMT+01:00 Felix Patzelt fe...@neuro.uni-bremen.de: Well, there is a list in ~/.matplotlib/matplotlibrc (see http://matplotlib.org/users/customizing.html) CONFIGURATION BEGINS HERE # the default backend; one of GTK GTKAgg GTKCairo CocoaAgg FltkAgg # MacOSX QtAgg Qt4Agg TkAgg WX WXAgg Agg Cairo GDK PS PDF SVG Template # You can also deploy your own backend outside of matplotlib by # referring to the module name (which must be in the PYTHONPATH) as # 'module://my_backend' backend : Qt4Agg see also: http://stackoverflow.com/questions/5091993/list-of-all-available-matplotlib-backends I'm not sure about the dependencies, I guess you have to check out each one of them. If you don't use a package manager, resolving all dependency issues might be quite painful. Best, Felix Patzelt Am 13.03.2014 um 17:18 schrieb Christophe Bal projet...@gmail.com: Thanks a lot for this big hint but neither TkAgg works nor Qt4Agg can work (because I do not have PyQt). Is there a complete list of all the backends ? Christophe BAL -- Learn Graph Databases - Download FREE O'Reilly Book Graph Databases is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available.
