[Matplotlib-users] PS and imshow
Hi, I'd like to open a high-quality image (600dpi) in matplotlib, add some plots and save it as a postscript file. It seems that whatever I do, the input image gets scaled down :-( The same question was asked year ago. Has any progress been made since then? http://sourceforge.net/mailarchive/message.php?msg_id=200608311227.30594.dd55%40cornell.edu Looking in the code of matplotlib, there is a constant of 72dpi hardwired everywhere. For instance, backend_ps.py there is the line self.figure.dpi.set(72) # ignore the dpi kwarg Would rising of this value to 600 help? No offence to developers, I did not even try to understand the code, but using the number 72 instead of using a variable seems to be a bad programming practice to me. Petr Danecek - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Vertical bar - making the bar fixed width
Alen Ribic wrote: > How do I set my vertical bar to be fixed width? By default, bars are created with a fixed width of 0.8, which can be changed with the width keyword arg like so: bar(range(2), range(1,3), width = 0.5) > Depending on amount of data on my x axis, the bars get created > accordingly and the width gets adjusted to fit into the graph. The width in pixels/proportion of axis is dependent on the range of the x-axis, which you can set manually too. There's probably a more elegant way of doing this, but here's a quick and dirty method for interactive mode (ipython/pylab): # Make a figure, catch the reference as f f = figure(1) # Draw some bars bar_list = bar(array([0,0.5,1.0]), array([1.0,2.0,3.0]), width = 0.25) # Get the subplot (f.axes is a list containing the subplots) s = f.axes[0] # Set the x-axis limits of the subplot s.set_xlim((-5.0, 5.0)) # Redraw draw() Fred - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Looking for a way to save a graph
OK I see... nothing straightforward... Best way for me is maybe to implement such a system myself: The system would collect the information to be saved by kind of introspection of the figure. I'm planning to save data and plot properties in an hdf5 file. Kind of inverted process will be used to restore the figure. Of course I will not cover the whole possible figure case but only what I'm currently using for my work. If somebody did similar work and is eager to share or if somebody have any suggestion please let me know. Thanks for the great matplotlib and to its community ! Regards, David - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Vertical bar - making the bar fixed width
Thanks Fred. Thant did the trick. However now, when I have many plots on x axis, the last few plot shoot of the end of the x axis. It seems to start the plotting the middle move to the right. Do I just have to adjust the xlim on the axes[0]? I fiddled with the "align" parameter, set it to "center", on the bar function and it didn't do much. -Alen > > On 8/24/07, Fred Ludlow <[EMAIL PROTECTED]> wrote: > > Alen Ribic wrote: > > > How do I set my vertical bar to be fixed width? > > > > By default, bars are created with a fixed width of 0.8, which can be > > changed with the width keyword arg like so: > > > > bar(range(2), range(1,3), width = 0.5) > > > > > > > Depending on amount of data on my x axis, the bars get created > > > accordingly and the width gets adjusted to fit into the graph. > > The width in pixels/proportion of axis is dependent on the range of the > > x-axis, which you can set manually too. > > > > There's probably a more elegant way of doing this, but here's a quick > > and dirty method for interactive mode (ipython/pylab): > > > > # Make a figure, catch the reference as f > > f = figure(1) > > > > # Draw some bars > > bar_list = bar(array([0,0.5,1.0]), array([1.0,2.0,3.0]), width = 0.25) > > > > # Get the subplot (f.axes is a list containing the subplots) > > s = f.axes[0] > > > > # Set the x-axis limits of the subplot > > s.set_xlim((-5.0, 5.0)) > > > > # Redraw > > draw() > > > > > > Fred > > > > - > > This SF.net email is sponsored by: Splunk Inc. > > Still grepping through log files to find problems? Stop. > > Now Search log events and configuration files using AJAX and a browser. > > Download your FREE copy of Splunk now >> http://get.splunk.com/ > > ___ > > Matplotlib-users mailing list > > Matplotlib-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > > - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
[Matplotlib-users] reversing the y axis
hi. i'm a new user of matplotlib. i've searched through the arhieves of the mailing list but couldn't find a quick solution. i simply need to reverse the y axis of my plots. for example in a range of 0-10, 0 must seem at the top of the plot where 10 is lowest, near to the x axis. is there a quick solution for this. (x axis must stay as it is) thanx... -- EMRE AYDIN [EMAIL PROTECTED] - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Vertical bar - making the bar fixed width
Alen Ribic wrote: > Thanks Fred. > > Thant did the trick. However now, when I have many plots on x axis, > the last few plot shoot of the end of the x axis. It seems to start > the plotting the middle move to the right. Do I just have to adjust > the xlim on the axes[0]? I fiddled with the "align" parameter, set it > to "center", on the bar function and it didn't do much. > > -Alen Hi Alen, The align parameter sets whether the left, or the center of the bar should be aligned with the x-value you give for that bar. So the right hand edge of the bar would be at x+width (or x + (width/2) for center), and you'd need to set x_lim to include this. If I've misunderstood your problem can you post the code that's causing trouble? Cheers, Fred ps. gca() also gets the current axes object, which is marginally less typing than what I said before, so you can use: gca().set_xlim([0.0, 10.0]) draw() to re-scale the x-axis on the last thing you plotted to 0.0-10.0. - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] reversing the y axis
On 8/24/07, Emre Aydın <[EMAIL PROTECTED]> wrote: > hi. i'm a new user of matplotlib. i've searched through the arhieves > of the mailing list but couldn't find a quick solution. i simply need > to reverse the y axis of my plots. for example in a range of 0-10, 0 > must seem at the top of the plot where 10 is lowest, near to the x > axis. is there a quick solution for this. (x axis must stay as it is) ylim(10, 0) JDH - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] reversing the y axis
# Get min and max from current axes y_min, y_max = gca().get_ylim() # Set the other way round for current axes gca().set_ylim(y_max, y_min) # Redraw draw() Emre Ayd?n wrote: > hi. i'm a new user of matplotlib. i've searched through the arhieves > of the mailing list but couldn't find a quick solution. i simply need > to reverse the y axis of my plots. for example in a range of 0-10, 0 > must seem at the top of the plot where 10 is lowest, near to the x > axis. is there a quick solution for this. (x axis must stay as it is) > > thanx... > - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] reversing the y axis
On 8/24/07, Fred Ludlow <[EMAIL PROTECTED]> wrote: > # Get min and max from current axes > y_min, y_max = gca().get_ylim() > > # Set the other way round for current axes > gca().set_ylim(y_max, y_min) > > # Redraw > draw() > > > Emre Ayd?n wrote: > > hi. i'm a new user of matplotlib. i've searched through the arhieves > > of the mailing list but couldn't find a quick solution. i simply need > > to reverse the y axis of my plots. for example in a range of 0-10, 0 > > must seem at the top of the plot where 10 is lowest, near to the x > > axis. is there a quick solution for this. (x axis must stay as it is) > > > > thanx... > > > > > > - > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > ___ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > thnx alot! that solved it... -- EMRE AYDIN [EMAIL PROTECTED] - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] PS and imshow
Petr Danecek wrote: > Hi, > I'd like to open a high-quality image (600dpi) in matplotlib, add some > plots and save it as a postscript file. > It seems that whatever I do, the input image gets scaled down > :-( I'm sorry I don't know enough about MPL's handling of images to help, but... > Looking in the code of matplotlib, there is a constant of 72dpi > hardwired everywhere. For instance, backend_ps.py there is the line > self.figure.dpi.set(72) # ignore the dpi kwarg This may not be what it seems. The native coordinate system for PostScript is in points, which are 1/72 if an inch, so it's common to force that as a dpi. Postscript supports fractional (is it floating point or fixed -- I'm not sure) points, however, so you can define things in higher resolution, and I'm pretty sure you can imbed an arbitrary dpi image in a a PostScript file, using the 72dpi to positions the image. The problem comes if the code, in addition to using 72dpi, also assumes integer coordinates, then you can't get better accuracy that 72dpi, which is not very good, and is really bad if someone scales it up later. wxWidgets addresses this by hard-coding 720dpi, rather than 72, and dividing by ten when writing the postscript -- still a bit of kludge. I'm not sure what MPL does. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R(206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [EMAIL PROTECTED] - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] PS and imshow
On 8/24/07, Christopher Barker <[EMAIL PROTECTED]> wrote: > This may not be what it seems. The native coordinate system for > PostScript is in points, which are 1/72 if an inch, so it's common to > force that as a dpi. Postscript supports fractional (is it floating > point or fixed -- I'm not sure) points, however, so you can define > things in higher resolution, and I'm pretty sure you can imbed an > arbitrary dpi image in a a PostScript file, using the 72dpi to positions > the image. Yes, this is exactly right and the reason we do it this way. We support fractional points so indeed you have higher resolutions. Off the top of my head, I am not sure what is going on with the image resolution problem JDH - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Looking for a way to save a graph
On 8/24/07, David Tremouilles <[EMAIL PROTECTED]> wrote: > OK I see... nothing straightforward... > > Best way for me is maybe to implement such a system myself: > The system would collect the information to be saved by kind of > introspection of the figure. > I'm planning to save data and plot properties in an hdf5 file. Kind of > inverted process will be used to restore the figure. > Of course I will not cover the whole possible figure case but only > what I'm currently using for my work. > If somebody did similar work and is eager to share or > if somebody have any suggestion please let me know. A huge +1 for this approach. Pickle is NOT meant to be a persistent, on-disk file format, but rather a way to serialize the *current* state of an object in memory. Emphasis on current: if you unpickle an old pickle in an environment where the class layout of your object (or any object the parent holds a reference to) has changed, the unpickling fails, completely and irrecoverably. As someone who has already had to write pickle loader functions to salvage old pickles (because computing them had been very expensive), I've learned my lesson. Pickle works well as a way to quickly dump/load data that is either made up of simple python types *only* (since they don't change often) or for objects that you have good reason to expect won't be changing their API while you care about the pickles. But pickling is NOT a 'data format', and using it as such will inevitably lead to much pain and suffering. HDF5 *is* a data format. In our project we precisely went to hdf5 instead of pickling. Cheers, f - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] PS and imshow
"John Hunter" <[EMAIL PROTECTED]> writes:
> On 8/24/07, Christopher Barker <[EMAIL PROTECTED]> wrote:
>
>> This may not be what it seems. The native coordinate system for
>> PostScript is in points, which are 1/72 if an inch, so it's common to
>> force that as a dpi. [...]
>
> Yes, this is exactly right and the reason we do it this way. We
> support fractional points so indeed you have higher resolutions. Off
> the top of my head, I am not sure what is going on with the image
> resolution problem
I just tried with current svn, and the following script produces two
results that have visibly different resolutions:
#!/usr/bin/python
from pylab import *
foo = rand(10,10)
imshow(foo)
savefig('foo10.ps', dpi=10)
savefig('foo100.ps', dpi=100)
Perhaps the original poster could show a bit of code where the scaling
fails?
(I'm not sure if figimage is doing the right thing, though...)
--
Jouni K. Seppänen
http://www.iki.fi/jks
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[Matplotlib-users] Error TclError: no display name and no $DISPLAY environment variable
Hi, I use matplotlib as part of my Trac plugin. I got this error when I try to access the web site that use my plugin. Please see the trace back below File "/u/bhuricha/lib/python2.5/site-packages/Trac- 0.11dev_r5933-py2.5.egg/trac/web/main.py", line 381, in dispatch_request File "/u/bhuricha/lib/python2.5/site-packages/Trac- 0.11dev_r5933-py2.5.egg/trac/web/main.py", line 191, in dispatch File "/u/bhuricha/source/trac-hacks/tracmetrixplugin/0.11/tracmetrixplugin/web_ui.py", line 119, in process_request File "/u/bhuricha/source/trac-hacks/tracmetrixplugin/0.11/tracmetrixplugin/web_ui.py", line 193, in _render_view File "/u/bhuricha/source/trac-hacks/tracmetrixplugin/0.11/tracmetrixplugin/model.py", line 452, in get_daily_backlog_chart File "/usr/lib/python2.5/site-packages/matplotlib/pylab.py", line 876, in figure File "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_tkagg.py", line 88, in new_figure_manager File "lib-tk/Tkinter.py", line 1639, in __init__ Local variables: NameValue baseName'trac.cgi' className'Tk' ext'.cgi' interactive0 os screenNameNone selfNone sync0 sys useNone useTk1 I am not sure what's wrong. I was able to get this to work in the different environment. Can anyone tell me what might be wrong? Thanks, Deen - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Error TclError: no display name and no $DISPLAY environment variable
"Deen Sethanandha" <[EMAIL PROTECTED]> writes:
> I use matplotlib as part of my Trac plugin. I got this error when I try
> to access the web site that use my plugin. [...]
>
> File "/usr/lib/python2.5/site-packages/matplotlib/pylab.py", line 876, in
> figure
> File
> "/usr/lib/python2.5/site-packages/matplotlib/backends/backend_tkagg.py",
> line 88, in new_figure_manager
> File "lib-tk/Tkinter.py", line 1639, in __init__
Your plugin is importing pylab, which automatically imports the TkAgg
backend based on your .matplotlibrc setting, and this makes no sense
in a non-interactive environment. The quick way to make this work is
to replace "import pylab" by the following lines:
import matplotlib
matplotlib.use('Agg')
import pylab
See also: examples/webapp_demo.py.
--
Jouni K. Seppänen
http://www.iki.fi/jks
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