matplotlib-users — Discussion related to using matplotlib

Re: [Matplotlib-users] How to properly use path.Path.contains_point?

[Benjamin R. <ben...@ou...>]

On Sat, Mar 23, 2013 at 12:09 AM, Russell Warren <ru...@pe...> wrote:

> I'm trying to use path.Path.contains_point for point-in-polygon testing
> and am running into a few different confusing situations.  My specific
> issues/questions are:
>
> 1. I'm seeing different behaviour dependent on path direction (clockwise
> or counter-clockwise).  Is there a "correct" direction to use?
>

No, it shouldn't matter, AFAICT.  If there are differences, then it should
be reported as a bug.


>
> 2. What is the expected behaviour for Path.contains_point when the point
> is on a boundary?
>
> The original algorithm that it was based off of considered it outside
(again, from memory), but warns that floating-point errors renders this
point largely theoretical.



> 3. What is the radius parameter supposed to do?  The docs say it "allows
> the path to be made slightly larger or smaller", but I'm clearly not
> understanding this properly (see the cw_path hit test failure with r=0.1
> below).
>
>
That is a terrible description of the functionality, I agree.  Essentially,
if you have a positive radius, it effectively dilates the polygon for the
purposes of point-testing, while a negative radius effectively erodes the
polygon (but not for plotting... only for point testing).



> Here is a short example showing some issues with a unit rectangle...
>
> >>> from matplotlib.path import Path
> >>> cw_path  = Path([[0,0], [0,1], [1,1], [1,0]])
> >>> ccw_path = Path([[0,0], [1,0], [1,1], [0,1]])
> >>> #Point on x axis not detected for either path...
> ... cw_path.contains_point([0.5, 0])
> 0
> >>> ccw_path.contains_point([0.5, 0])
> 0
> >>> #Add a large radius and ccw_path works, but not cw_path (!!?)...
> ... r = 0.1
> >>> cw_path.contains_point([0.5, 0], radius=r)
> 0
> >>> ccw_path.contains_point([0.5, 0], radius=r)
> 1
>
> The following ipython notebook has more detailed tests, but the main
> points are in the sample above.
> http://nbviewer.ipython.org/7e1b347b8b21b338bee1
>
> I've found at least one reference [1] online indicating that "this
> function is intended for use when mouse-clicking".  Does that mean I should
> not use it for generic point-in-polygon testing?
>
>
That entirely depends upon your needs.  The algorithm has very low
overhead, but it isn't highly optimized.  This makes it ideal for
occasional point tests on arbitrary polygons (such as processing
mouse-clicks).  But if you want to systematically do many point tests for
every single polygon, then maybe a more rigorously designed and implemented
algorithm (such as Shapely's) is more suited for your needs.  Note that
Shapely's algorithm has higher overhead, but can test many more points
faster than ours.

I hope that clears things up!
Ben Root

Re: [Matplotlib-users] MonthLocator doesn't honour rrule bymonthday -1 value for last day of month

[Mark L. <bre...@ya...>]

I've found the solution.  MonthLocator doesn't support the bysetpos 
argument that rrule can use.  Thankfully from my POV the following two 
lines give me exactly what I want.

rule = rrulewrapper(MONTHLY, bymonthday=(firstDate.day, -1), bysetpos=1)
majorLocator = RRuleLocator(rule)

Just wish I'd read the docs more carefully in the first place to save my 
time and yours.

On 05/04/2013 10:17, Mark Lawrence wrote:
> On 04/04/2013 19:00, Mark Lawrence wrote:
>> Sadly no :(  I want the day of the month that I'm processing *OR* the
>> last day.  The worst case for this is obviously the 31st of each month.
>>    The rrule code I've given provides exactly that.  When transferred to
>> mpl that doesn't work.
>
> Best seen by changing the lines I gave originally to this.
>
> start = datetime.date(2013, 4, 5)
> until = datetime.date(2014, 4, 5)
> dates = rrule(MONTHLY, bymonthday=(5, -1), bysetpos=1, until=until)
>
> rrule output as follows.
>
> 2013-04-05 10:15:24
> 2013-05-05 10:15:24
> 2013-06-05 10:15:24
> 2013-07-05 10:15:24
> 2013-08-05 10:15:24
> 2013-09-05 10:15:24
> 2013-10-05 10:15:24
> 2013-11-05 10:15:24
> 2013-12-05 10:15:24
> 2014-01-05 10:15:24
> 2014-02-05 10:15:24
> 2014-03-05 10:15:24
>
> Plot attached.
>
>>
>> On 04/04/2013 17:31, Phil Elson wrote:
>>> Hi Mark,
>>>
>>> Thanks for persevering :-)
>>>
>>> What is it you want to achieve? Is it that you just want the last day of
>>> each month as the located value?
>>>
>>> Changing your locator to:
>>>
>>> ax.xaxis.set_major_locator(MonthLocator(bymonthday = -1))
>>>
>>> Seems to do the trick for me (I've never looked at the mpl date magic,
>>> so I can give no guarantees).
>>>
>>> HTH,
>>>
>>>
>>> On 4 April 2013 17:18, Mark Lawrence
>>> <bre...@ya...
>>> <mailto:bre...@ya...>> wrote:
>>>
>>>      On 01/04/2013 14:48, Mark Lawrence wrote:
>>>       > On 29/03/2013 15:49, Mark Lawrence wrote:
>>>       >> Hi all,
>>>       >>
>>>       >>    From http://labix.org/python-dateutil
>>>       >>
>>>       >> "To generate a rrule for the use case of "a date on the
>>>      specified day of
>>>       >> the month, unless it is beyond the end of month, in which case
>>>      it will
>>>       >> be the last day of the month" use the following:
>>>       >>
>>>       >> rrule(MONTHLY, bymonthday=(some_day, -1), bysetpos=1)
>>>       >>
>>>       >> This will generate a value for every calendar month regardless
>>>      of the
>>>       >> day of the month it is started from."
>>>       >>
>>>       >> Using bymonthday with MonthLocator gives ticks on the day given
>>>      and the
>>>       >> last day of the month, which looks extremely ugly.  Code below
>>>      demonstrates.
>>>       >>
>>>       >> from dateutil.rrule import *
>>>       >> import datetime
>>>       >> import matplotlib.pyplot as plt
>>>       >> from matplotlib.ticker import FormatStrFormatter,
>>> MultipleLocator
>>>       >> from matplotlib.dates import DateFormatter, MonthLocator,
>>> DayLocator
>>>       >>
>>>       >> start = datetime.date(2013, 3, 29)
>>>       >> until = datetime.date(2014, 3, 29)
>>>       >> dates = rrule(MONTHLY, bymonthday=(29, -1), bysetpos=1,
>>> until=until)
>>>       >> for d in dates:print(d)
>>>       >>
>>>       >> dates = [start, until]
>>>       >> values = [0, 1]
>>>       >> plt.ylabel('Balance')
>>>       >> plt.grid()
>>>       >> ax = plt.subplot(111)
>>>       >> plt.plot_date(dates, values, fmt = 'rx-')
>>>       >> ax.xaxis.set_major_locator(MonthLocator(bymonthday =
>>>      (dates[0].day, -1)))
>>>       >> ax.xaxis.set_major_formatter(DateFormatter('%d/%m/%y'))
>>>       >> ax.yaxis.set_major_formatter(FormatStrFormatter('£%0.2f'))
>>>       >> ax.yaxis.set_minor_locator(MultipleLocator(5))
>>>       >> plt.axis(xmin=dates[0], xmax=dates[-1])
>>>       >> plt.setp(plt.gca().get_xticklabels(), rotation = 45,
>>> fontsize = 10)
>>>       >> plt.setp(plt.gca().get_yticklabels(), fontsize = 10)
>>>       >> plt.show()
>>>       >>
>>>       >
>>>       > Seems an apt date to realise that I didn't say much :(
>>>       >
>>>       > Assuming that I'm correct would you like an issue raised on
>>> the bug
>>>       > tracker?  If not please correct the mistake I've made,
>>> presumably in
>>>       > reading the docs, which I think are excellent by the way.
>>>       >
>>>
>>>      Anybody?
>>>
>>>      --
>>>      If you're using GoogleCrap™ please read this
>>>      http://wiki.python.org/moin/GoogleGroupsPython.
>>>
>>



-- 
If you're using GoogleCrap™ please read this 
http://wiki.python.org/moin/GoogleGroupsPython.

Mark Lawrence

[Matplotlib-users] how to use x11 as backend for matplotlib on Mountain Lion of Mac OSX?

[Randy B. L. <mum...@gm...>]

hi, every one:

I used to use TkAgg as backend on my macbook for matplotlib which was
installed from macports. for a while, the plot window was launched in X11.
after a latest macports update, it stopped using x11 instead a standalone
python window will be used now.

I was wondering if there is a way to instruct matplotlib to open plot
window in x11? thanks!
-- 

Randy

Re: [Matplotlib-users] basemap scatter

[ChaoYue <cha...@gm...>]

I'm afraid the scatter plot does not allow afterward adjustment with size
currently (by using setp).
Probably you should redraw the scatter points with different sizes. like

for x,y,z in zip(xlist,ylist,sizelist):
     m.scatter(x,y,s=z)

if you question is to change the real 2km or 1.5km to the size on the map,
sorry I don't know as I never did this. Probably you need  consider
projection.

Chao


On Fri, Apr 12, 2013 at 4:33 PM, marz_cyclone [via matplotlib] <
ml-...@n5...> wrote:

> Hi all,
>
> I'm trying to do a scatter plot within a map created by basemap.
>
> m = Basemap(projection='ortho',lat_0=45,lon_0=0,resolution='l')
> X,Y = m(lon,lat)
> m.scatter(X,Y,s=sizes,c=data,edgecolor='none')
>
> This works fine. Now I want to change the sizes of the markers so that the
> marker at point A has a size that corresponds to circle with radius of 2.5
> km, point B to 1.5 km, .... and so on.
>
> Has anyone ever done this?
>
> Thanks in advance.
>
> Mario Mech
>
>
> ------------------------------------------------------------------------------
>
> Precog is a next-generation analytics platform capable of advanced
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[Matplotlib-users] basemap scatter

[Mario M. <me...@me...>]

Hi all,

I'm trying to do a scatter plot within a map created by basemap.

m = Basemap(projection='ortho',lat_0=45,lon_0=0,resolution='l')
X,Y = m(lon,lat)
m.scatter(X,Y,s=sizes,c=data,edgecolor='none')

This works fine. Now I want to change the sizes of the markers so that the marker at point A has a size that corresponds to circle with radius of 2.5 
km, point B to 1.5 km, .... and so on.

Has anyone ever done this?

Thanks in advance.

Mario Mech

Re: [Matplotlib-users] Linewidths in data space?

[Michael D. <md...@st...>]

Unfortunately, I don't think there is a way to do this at present.  Out 
of curiosity, what is the use case?

I wonder if the best way to do this would be to expose the stroking to 
the Python level, so given a line one could get a filled path that is 
the stroked line.  I'm not sure how else this could work, since the 
zooming could be different in each direction, etc., or could even by 
log-scaled etc.

Would you mind creating an issue ticket for this?  (Patches welcome, 
too, of course, and I can provide pointers if you want to take this on 
yourself...)

Mike

On 04/12/2013 05:34 AM, Michael Wimmer wrote:
> I have a collection of Patches and Lines that have their coordinates in
> data space, i.e. like in the following example:
>
>
> import matplotlib.pyplot as plt
> import matplotlib.patches as mpatches
> import matplotlib.collections as mcollections
> import matplotlib.lines as mlines
>
> fig = plt.figure()
> ax = fig.add_subplot(111)
>
> patches = []
> patches.append(mlines.Line2D((0,1),(0,1), linewidth=1))
> patches.append(mpatches.Circle((0,0), 0.25, linewidth=1))
> patches.append(mpatches.Circle((1,1), 0.25, linewidth=1))
>
> coll = mcollections.PatchCollection(patches)
> ax.add_collection(coll)
> ax.autoscale_view()
>
> plt.show()
>
>
> Now, in this example the line width is always given with respect to the
> screen space, i.e. does not change when I zoom into the plot. Is it
> possible to specify a linewidth with respect to data space? I.e. to say
> that a line (in both the Line2D and the Circle) should be let's say 0.1
> in data space, and thus scale accordingly if I zoom in?
>
> -Michael
>
> ------------------------------------------------------------------------------
> Precog is a next-generation analytics platform capable of advanced
> analytics on semi-structured data. The platform includes APIs for building
> apps and a phenomenal toolset for data science. Developers can use
> our toolset for easy data analysis & visualization. Get a free account!
> http://www2.precog.com/precogplatform/slashdotnewsletter
> _______________________________________________
> Matplotlib-users mailing list
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Re: [Matplotlib-users] Impossible to draw a direction of arrows in Matplotlib???

[andrew n. <and...@gm...>]

> 
> Message: 1
> Date: Fri, 12 Apr 2013 13:55:32 +0400
> From: Bakhtiyor Zokhidov <bak...@ma...>
> Subject: [Matplotlib-users] Impossible to draw a direction of arrows
> 	in Matplotlib???
> 
> Hi,
> I have encountered some problem while I was drawing a direction of
> arrow. I have point (x,y) coordinates and angle of them. What I want to
> do is that to draw arrow according to the given angle (just to show the
> point direction as an arrow in each point coordinate). Here, we should
> assume coordinates of '+x', '+y', '-x ', '-y' are 90, 0, 270, 180
> degrees, respectively.?
> I am a bit unfamiliar with Python drawing tools. I am still not sure to
> draw directional point (arrow based on angle) whether I use pylab or
> some other modules or.. still not sure at all. I put the following codes
> as a sample to give better description:




I see the potential for some confusion over the direction of arrows on a plot here.  In standard trigonometry angles of 0, 90, 180, 270 degrees lie along '+x' (1, 0), '+y' (0, 1), '-x' (-1, 0) and '-y' (0, -1).  Totally different to what you want.  However, this is obviously different to the compass rose.




________________
Dr Andrew Nelson
and...@gm...
_________________

Re: [Matplotlib-users] Impossible to draw a direction of arrows in Matplotlib???

[Ryan N. <rne...@gm...>]

I'm not sure that I understand exactly what you are trying to do, but 
you may want to look into Matplotlib annotation. Here's a really quick 
example:

import matplotlib.pyplot as plt
plt.annotate('', (1, 1), (0, 0),
         arrowprops=dict(facecolor='black'))
plt.axis([-1, 2, -1, 2])
plt.show()

There are many options to make very fancy arrows, and there are several 
places in the docs to read about this in more detail:
http://matplotlib.org/users/annotations_intro.html
http://matplotlib.org/users/annotations_guide.html

Hope that helps a little. Good luck.

Ryan

On 4/12/2013 5:55 AM, Bakhtiyor Zokhidov wrote:
> Hi,
> I have encountered some problem while I was drawing a direction of
> arrow. I have point (x,y) coordinates and angle of them. What I want to
> do is that to draw arrow according to the given angle (just to show the
> point direction as an arrow in each point coordinate). Here, we should
> assume coordinates of '+x', '+y', '-x ', '-y' are 90, 0, 270, 180
> degrees, respectively.
> I am a bit unfamiliar with Python drawing tools. I am still not sure to
> draw directional point (arrow based on angle) whether I use pylab or
> some other modules or.. still not sure at all. I put the following codes
> as a sample to give better description:
>
> import numpy as np
> import scipy as sp
> import pylab as pl
>
>
> def draw_line(x,y,angle):
>      # Inputs:
>      x = np.array([ 2, 4, 8, 10, 12, 14, 16])
> y = np.array([ 5, 10, 15, 20, 25, 30, 35])
> angles = np.array([45,275,190,100,280,18,45])
>
> # First, draw (x,y) coordinate
> ???
> # Second, according to the angle indicate the direction as
> an arrow
> ???
>
> Thanks in advance for your friendly support,
>
>
> ------------------------------------------------------------------------------
> Precog is a next-generation analytics platform capable of advanced
> analytics on semi-structured data. The platform includes APIs for building
> apps and a phenomenal toolset for data science. Developers can use
> our toolset for easy data analysis & visualization. Get a free account!
> http://www2.precog.com/precogplatform/slashdotnewsletter
>
>
> _______________________________________________
> Matplotlib-users mailing list
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> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

[Matplotlib-users] Impossible to draw a direction of arrows in Matplotlib???

[Bakhtiyor Z. <bak...@ma...>]

 Hi,
I have encountered some problem while I was drawing a direction of
arrow. I have point (x,y) coordinates and angle of them. What I want to
do is that to draw arrow according to the given angle (just to show the
point direction as an arrow in each point coordinate). Here, we should
assume coordinates of '+x', '+y', '-x ', '-y' are 90, 0, 270, 180
degrees, respectively. 
I am a bit unfamiliar with Python drawing tools. I am still not sure to
draw directional point (arrow based on angle) whether I use pylab or
some other modules or.. still not sure at all. I put the following codes
as a sample to give better description:

import numpy as np
import scipy as sp
import pylab as pl


def draw_line(x,y,angle):
     # Inputs:
     x = np.array([ 2, 4, 8, 10, 12, 14, 16])
      y = np.array([ 5, 10, 15, 20, 25, 30, 35])
      angles = np.array([45,275,190,100,280,18,45]) 
 
      # First, draw (x,y) coordinate
      ???
      # Second, according to the angle indicate the direction as
      an arrow
      ???

Thanks in advance for your friendly support,

[Matplotlib-users] Linewidths in data space?

[Michael W. <wim...@gm...>]

I have a collection of Patches and Lines that have their coordinates in
data space, i.e. like in the following example:


import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import matplotlib.collections as mcollections
import matplotlib.lines as mlines

fig = plt.figure()
ax = fig.add_subplot(111)

patches = []
patches.append(mlines.Line2D((0,1),(0,1), linewidth=1))
patches.append(mpatches.Circle((0,0), 0.25, linewidth=1))
patches.append(mpatches.Circle((1,1), 0.25, linewidth=1))

coll = mcollections.PatchCollection(patches)
ax.add_collection(coll)
ax.autoscale_view()

plt.show()


Now, in this example the line width is always given with respect to the
screen space, i.e. does not change when I zoom into the plot. Is it
possible to specify a linewidth with respect to data space? I.e. to say
that a line (in both the Line2D and the Circle) should be let's say 0.1
in data space, and thus scale accordingly if I zoom in?

-Michael

Re: [Matplotlib-users] Pan/Zoom can't work with blitting

[Clare S. <cla...@gm...>]

Hi Michiel,

I'm using GtkAgg. Please correct me if I'm wrong, but issue 531's problem
is with blitting, for me blitting works, I'm able to speed up plotting
using canvas.copy_from_bbox(), canvas.restore_region() & canvas.blit().
It's just that after plotting, if I try to pan or zoom using the pan/zoom
buttons on the navigation toolbar, whatever I've plotted disappears & the
whole thing becomes blank. I'm able to pan/zoom if I use canvas.draw() but
plotting is too slow because it redraws everything.

Regards,
Clare.

On Fri, Apr 12, 2013 at 8:22 AM, Michiel de Hoon <mjl...@ya...>wrote:

>   Hi Clare,
>
> Which backend are you using, and can you show an example script?
>
> The blitting functions are a bit unusual as they try to draw stuff to the
> figure outside of the event loop. This is e.g. causing problems with
> animations, which makes use of the blitting functions. We have been looking
> at that recently (see https://github.com/matplotlib/matplotlib/issues/531)
> but we haven't come up with a solution yet. Solving this issue may also fix
> your problem (which sounds like an event loop problem), so you may want to
> follow issue 531.
>
> Best,
> -Michiel.
>
> --- On *Thu, 4/11/13, Clare Soh <cla...@gm...>* wrote:
>
>
> From: Clare Soh <cla...@gm...>
> Subject: [Matplotlib-users] Pan/Zoom can't work with blitting
> To: "mat...@li..." <
> mat...@li...>
> Date: Thursday, April 11, 2013, 5:19 AM
>
>
>  Hi,
>
> To improve plotting speed, I decided
> to use blitting(canvas.copy_from_bbox(), canvas.restore_region() &
> canvas.blit()) instead of canvas.draw(), however panning & zooming stops
> working after this change. Now, when I click on the 'Pan/Zoom' button or
> the 'Zoom to rectangle' button on the Navigation Toolbar, my plot becomes
> empty. I don't know what's going wrong, can someone please point me in the
> right direction?
>
> Thank you,
> Clare.
>
> -----Inline Attachment Follows-----
>
>
> ------------------------------------------------------------------------------
> Precog is a next-generation analytics platform capable of advanced
> analytics on semi-structured data. The platform includes APIs for building
> apps and a phenomenal toolset for data science. Developers can use
> our toolset for easy data analysis & visualization. Get a free account!
> http://www2.precog.com/precogplatform/slashdotnewsletter
>
> -----Inline Attachment Follows-----
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...<http://mc/compose?to=...@li...>
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>

Re: [Matplotlib-users] Pan/Zoom can't work with blitting

[Michiel de H. <mjl...@ya...>]

Hi Clare,

Which backend are you using, and can you show an example script?

The blitting functions are a bit unusual as they try to draw stuff to the figure outside of the event loop. This is e.g. causing problems with animations, which makes use of the blitting functions. We have been looking at that recently (see https://github.com/matplotlib/matplotlib/issues/531) but we haven't come up with a solution yet. Solving this issue may also fix your problem (which sounds like an event loop problem), so you may want to follow issue 531.

Best,
-Michiel.

--- On Thu, 4/11/13, Clare Soh <cla...@gm...> wrote:

From: Clare Soh <cla...@gm...>
Subject: [Matplotlib-users] Pan/Zoom can't work with blitting
To: "mat...@li..." <mat...@li...>
Date: Thursday, April 11, 2013, 5:19 AM

Hi,
 
To improve plotting speed, I decided to use blitting(canvas.copy_from_bbox(), canvas.restore_region() & canvas.blit()) instead of canvas.draw(), however panning & zooming stops working after this change. Now, when I click on the 'Pan/Zoom' button or the 'Zoom to rectangle' button on the Navigation Toolbar, my plot becomes empty. I don't know what's going wrong, can someone please point me in the right direction?

 
Thank you,
Clare.

-----Inline Attachment Follows-----

------------------------------------------------------------------------------
Precog is a next-generation analytics platform capable of advanced
analytics on semi-structured data. The platform includes APIs for building
apps and a phenomenal toolset for data science. Developers can use
our toolset for easy data analysis & visualization. Get a free account!
http://www2.precog.com/precogplatform/slashdotnewsletter
-----Inline Attachment Follows-----

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[Matplotlib-users] Pan/Zoom can't work with blitting

[Clare S. <cla...@gm...>]

Hi,

To improve plotting speed, I decided
to use blitting(canvas.copy_from_bbox(), canvas.restore_region() &
canvas.blit()) instead of canvas.draw(), however panning & zooming stops
working after this change. Now, when I click on the 'Pan/Zoom' button or
the 'Zoom to rectangle' button on the Navigation Toolbar, my plot becomes
empty. I don't know what's going wrong, can someone please point me in the
right direction?

Thank you,
Clare.

Re: [Matplotlib-users] Appending an extra column in

[Maximilian T. <fa...@tr...>]

Hi,

for reading the data files you could user np.loadtxt("filename").

I'm not sure what kind of plot you want to create from this data, but
probably you can find an appropriate plotting method on this page:
http://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html

Max

PS: Sorry for not sending my first mail to the list, but you can see it
below

Am 11/04/2013 04:54, schrieb Sayan Chatterjee:
> Thanks Maximillian for your help.
> 
> Could you please tell me how to surface plot with those data files using
> Matplotlib?...i.e both reading the data files and then surface plotting
> in matplotlib?
> 
> Sayan
> 
> 
> On 11 April 2013 02:25, Maximilian Trescher <fa...@tr...
> <mailto:fa...@tr...>> wrote:
> 
>     Hi,
>     >
>     >   *np.savetxt(fname, np.array([pp_za,pv_za]).T, '%f')*
> 
>     does maybe
> 
>     np.savetxt(fname, np.array([pp_za,pv_za, np.ones(1000)*t]).T, '%f')
>     does what you want? (replace 1000 with approppriate length)
> 
>     and a comment about:
>     >      if pp_za[i] < 0:
>     >       pp_za[i] = 2 - abs(pp_za[i])
>     >     if pp_za[i] > 2:
>     >       pp_za[i] = pp_za[i] % 2
> 
>     in general
> 
>     pp_za[pp_za < 0] = 2 - abs(pp_za[pp_za < 0])
>     pp_za[pp_za > 2] = pp_za[pp_za > 2] % 2
> 
>     is shorter and much faster.
> 
>     Max
> 
> 
> 
> 
> 
> 
> -- 
> 
> 
> --------------------------------------------------------------------------
> *Sayan  Chatterjee*
> Dept. of Physics and Meteorology
> IIT Kharagpur
> Lal Bahadur Shastry Hall of Residence
> Room AB 205
> Mob: +91 9874513565
> blog: www.blissprofound.blogspot.com <http://www.blissprofound.blogspot.com>
> 
> Volunteer , Padakshep
> www.padakshep.org <http://www.padakshep.org>

Re: [Matplotlib-users] Appending an extra column in

[Sayan C. <say...@gm...>]

Thanks Maximillian for your help.

Could you please tell me how to surface plot with those data files using
Matplotlib?...i.e both reading the data files and then surface plotting in
matplotlib?

Sayan


On 11 April 2013 02:25, Maximilian Trescher <fa...@tr...> wrote:

> Hi,
> >
> >   *np.savetxt(fname, np.array([pp_za,pv_za]).T, '%f')*
>
> does maybe
>
> np.savetxt(fname, np.array([pp_za,pv_za, np.ones(1000)*t]).T, '%f')
> does what you want? (replace 1000 with approppriate length)
>
> and a comment about:
> >      if pp_za[i] < 0:
> >       pp_za[i] = 2 - abs(pp_za[i])
> >     if pp_za[i] > 2:
> >       pp_za[i] = pp_za[i] % 2
>
> in general
>
> pp_za[pp_za < 0] = 2 - abs(pp_za[pp_za < 0])
> pp_za[pp_za > 2] = pp_za[pp_za > 2] % 2
>
> is shorter and much faster.
>
> Max
>
>
>
>


-- 


--------------------------------------------------------------------------
*Sayan  Chatterjee*
Dept. of Physics and Meteorology
IIT Kharagpur
Lal Bahadur Shastry Hall of Residence
Room AB 205
Mob: +91 9874513565
blog: www.blissprofound.blogspot.com

Volunteer , Padakshep
www.padakshep.org

[Matplotlib-users] Basemap crash with testgdal example script

[K.-Michael A. <kmi...@gm...>]

The example script 'testgdal.py' is crashing at the point of the 
basemap object instantiation:

m = Basemap(llcrnrlon=-119,llcrnrlat=22,urcrnrlon=-64,urcrnrlat=49,
            projection='lcc',lat_1=33,lat_2=45,lon_0=-95)
Assertion failed: (0), function query, file AbstractSTRtree.cpp, line 286.
Abort trap: 6

Is there a known workaround?

with basemap version 1.0.2

Best,
Michael

Re: [Matplotlib-users] timeseries forecast error?

[Paul H. <pmh...@gm...>]

On Wed, Apr 10, 2013 at 2:46 PM, Tim Michelsen
<tim...@gm...>wrote:

> Hello,
> how can I show the forecast error for a timeseries?
>
> Example:
>
> I am looking for displaying the blue area of:
>
> http://t3.gstatic.com/images?q=tbn:ANd9GcR9yuoMhiDeqxJVIOmp0EDNS_Sgxhtv4Z-ohlWly6N7zcgf28QD
>
> Or the violett areas on:
> http://www.meteopower.com/typo3temp/pics/3aa4157df7.jpg
>
> http://t1.gstatic.com/images?q=tbn:ANd9GcQt_l3HXOPigra-9LD5ldvwHytWc2NcP7cySIqp-8HFaOlZ6mrU7w
>
>
> http://matplotlib.org/api/axes_api.html?highlight=error#matplotlib.axes.Axes.errorbar
>
> Maybe as an envelope of
> http://matplotlib.org/examples/pylab_examples/errorbar_subsample.html
>
> Thanks for any pointers in advance and kind regards,
> Timmie
>

Timmie,

I would just use the fill_between method
http://matplotlib.org/examples/pylab_examples/fill_between_demo.html?highlight=codex%20fill_between

[Matplotlib-users] timeseries forecast error?

[Tim M. <tim...@gm...>]

Hello,
how can I show the forecast error for a timeseries?

Example:

I am looking for displaying the blue area of:
http://t3.gstatic.com/images?q=tbn:ANd9GcR9yuoMhiDeqxJVIOmp0EDNS_Sgxhtv4Z-ohlWly6N7zcgf28QD

Or the violett areas on:
http://www.meteopower.com/typo3temp/pics/3aa4157df7.jpg
http://t1.gstatic.com/images?q=tbn:ANd9GcQt_l3HXOPigra-9LD5ldvwHytWc2NcP7cySIqp-8HFaOlZ6mrU7w

http://matplotlib.org/api/axes_api.html?highlight=error#matplotlib.axes.Axes.errorbar

Maybe as an envelope of
http://matplotlib.org/examples/pylab_examples/errorbar_subsample.html

Thanks for any pointers in advance and kind regards,
Timmie

[Matplotlib-users] Appending an extra column in

[Sayan C. <say...@gm...>]

Dear All,

I have some data files with numpy arrays stored in it in 2 columns. I want
to add a third column with just floating point numbers(not numpy array) and
plot them later with Matplotlib in 3d. How is it done? Could you please
illuminate me?

This is the concerned snippet of the code:


while *t < 1*:


  pp_za = pp_init + t*K*np.sin(K*pp_init)

# Periodic Boundary Condition

  for i in range(0,999):

    if pp_za[i] < 0:
      pp_za[i] = 2 - abs(pp_za[i])
    if pp_za[i] > 2:
      pp_za[i] = pp_za[i] % 2

  pv_za = +K*np.sin(K*pp_init)

  fname = 'file_' + str(t) + '.dat'

# Generating dataset for Phase Space diagram

  *np.savetxt(fname, np.array([pp_za,pv_za]).T, '%f')*

  t = t + 0.01

And the sample data generated is :

0.105728 0.098678
0.126865 0.118406
0.147998 0.138128
0.169126 0.157845
0.190247 0.177556
0.211362 0.197259
0.232469 0.216955
0.253567 0.236643
0.274657 0.256321
0.295737 0.275989
0.316806 0.295646

Precisely what I want is, I want to add the 't' (over which the while loop
is run) in the 3 rd column. 't' is float and constant for each looping. If
you know what a phase plot is(doesn't matter if you don't), I want to see
the phase plot evolving with time. Thus the need of a time axis and hence
plot with V(velocity-Yaxis), X ( Position -X axis) and t (Time-Z axis).Once
the data files are created properly, how to plot them using Matplotlib?



Regards,
Sayan
-- 


--------------------------------------------------------------------------
*Sayan  Chatterjee*
Dept. of Physics and Meteorology
IIT Kharagpur
Lal Bahadur Shastry Hall of Residence
Room AB 205
Mob: +91 9874513565
blog: www.blissprofound.blogspot.com

Volunteer , Padakshep
www.padakshep.org

Re: [Matplotlib-users] Overriding Save button on Toolbar

[Will W. <wil...@gm...>]

Answering my own question - the solution is to add a binding to the save
button, and prevent the event from propagating after calling new_save() by
adding 'return "break"' at the end:

def new_save(self, *args, **kwargs):
    print 'save_figure pressed'
    return "break"

get_current_fig_manager().toolbar.bsave.bind('<Button-1>', new_save)

I would still like to know why the mechanism that works for the Home button
fails for the Save button though...

Will



On Wed, Apr 10, 2013 at 12:00 PM, Will Woods <wil...@gm...> wrote:

> Hmm, problems with html, will try again in plain text:
>
>
> I'm trying to override the behaviour of the toolbar, with partial success.
>
> This works:
>
>
> from matplotlib.backend_bases import NavigationToolbar2
>
> home = NavigationToolbar2.home
>
> def new_home(self, *args, **kwargs):
>     print 'home pressed'
>     home(self, *args, **kwargs)
>
> NavigationToolbar2.home = new_home
>
>
>
>
> ...but this doesn't:
>
>
>
>
> from matplotlib.backend_bases import NavigationToolbar2
>
> save_figure = NavigationToolbar2.save_figure
>
> def new_save(self, *args, **kwargs):
>     print 'save_figure pressed'
>     save_figure(self, *args, **kwargs)
>
> NavigationToolbar2.save_figure = new_save
>
>
>
>
> Having actually created a figure, I can get a bound method for save_figure:
>
>
> get_current_fig_manager().toolbar.save_figure()
>
>
>
> This I can override, and call my override function successfully from my
> script - but pressing the save button on the toolbar doesn't call my
> function...
>
> I'm running matplotlib 1.1.1rc and python 2.7.3
>
> Thanks,
>
> Will
>
>
>
>
>
>
>
>
> On Wed, Apr 10, 2013 at 11:55 AM, Willw <wil...@gm...> wrote:
>
>> I'm trying to override the behaviour of the toolbar, with partial success.
>>
>> This works:
>>
>>
>>
>> ...but this doesn't:
>>
>>
>>
>> Having actually created a figure, I can get a bound method for
>> save_figure:
>>
>>
>>
>> This I can override, and call my override function successfully from my
>> script - but pressing the save button on the toolbar doesn't call my
>> function...
>>
>> I'm running matplotlib 1.1.1rc and python 2.7.3
>>
>> Thanks,
>>
>> Will
>>
>>
>>
>>
>> --
>> View this message in context:
>> http://matplotlib.1069221.n5.nabble.com/Overriding-Save-button-on-Toolbar-tp40864.html
>> Sent from the matplotlib - users mailing list archive at Nabble.com.
>>
>>
>> ------------------------------------------------------------------------------
>> Precog is a next-generation analytics platform capable of advanced
>> analytics on semi-structured data. The platform includes APIs for building
>> apps and a phenomenal toolset for data science. Developers can use
>> our toolset for easy data analysis & visualization. Get a free account!
>> http://www2.precog.com/precogplatform/slashdotnewsletter
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>
>

Re: [Matplotlib-users] Overriding Save button on Toolbar

[Will W. <wil...@gm...>]

Hmm, problems with html, will try again in plain text:

I'm trying to override the behaviour of the toolbar, with partial success.

This works:


from matplotlib.backend_bases import NavigationToolbar2

home = NavigationToolbar2.home

def new_home(self, *args, **kwargs):
    print 'home pressed'
    home(self, *args, **kwargs)

NavigationToolbar2.home = new_home




...but this doesn't:




from matplotlib.backend_bases import NavigationToolbar2

save_figure = NavigationToolbar2.save_figure

def new_save(self, *args, **kwargs):
    print 'save_figure pressed'
    save_figure(self, *args, **kwargs)

NavigationToolbar2.save_figure = new_save



Having actually created a figure, I can get a bound method for save_figure:


get_current_fig_manager().toolbar.save_figure()


This I can override, and call my override function successfully from my
script - but pressing the save button on the toolbar doesn't call my
function...

I'm running matplotlib 1.1.1rc and python 2.7.3

Thanks,

Will








On Wed, Apr 10, 2013 at 11:55 AM, Willw <wil...@gm...> wrote:

> I'm trying to override the behaviour of the toolbar, with partial success.
>
> This works:
>
>
>
> ...but this doesn't:
>
>
>
> Having actually created a figure, I can get a bound method for save_figure:
>
>
>
> This I can override, and call my override function successfully from my
> script - but pressing the save button on the toolbar doesn't call my
> function...
>
> I'm running matplotlib 1.1.1rc and python 2.7.3
>
> Thanks,
>
> Will
>
>
>
>
> --
> View this message in context:
> http://matplotlib.1069221.n5.nabble.com/Overriding-Save-button-on-Toolbar-tp40864.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
> ------------------------------------------------------------------------------
> Precog is a next-generation analytics platform capable of advanced
> analytics on semi-structured data. The platform includes APIs for building
> apps and a phenomenal toolset for data science. Developers can use
> our toolset for easy data analysis & visualization. Get a free account!
> http://www2.precog.com/precogplatform/slashdotnewsletter
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

[Matplotlib-users] Overriding Save button on Toolbar

[Willw <wil...@gm...>]

I'm trying to override the behaviour of the toolbar, with partial success.

This works:



...but this doesn't:



Having actually created a figure, I can get a bound method for save_figure:



This I can override, and call my override function successfully from my
script - but pressing the save button on the toolbar doesn't call my
function...

I'm running matplotlib 1.1.1rc and python 2.7.3

Thanks,

Will




--
View this message in context: http://matplotlib.1069221.n5.nabble.com/Overriding-Save-button-on-Toolbar-tp40864.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Re: [Matplotlib-users] verts

[Steven B. <bo...@ph...>]

Thanks Zach,

That simple little example makes more sense than the manual page did. 
Perhaps it's just late.

I appreciate it.

Steven

On Mon Apr  8 22:30:43 2013, Zachary Pincus wrote:
>> I've got some verts I stole from the internet that draws an upward arrow
>> (or a down arrow), but I need to draw an arrow to the right or to the
>> left. But I don't really understand verts and how they work.
>>
>> arrowup_verts = [[0.,0.], [-1., -1], [0.,0.], [0.,-2.],[0.,0.], [1,-1]]
>> arrowdown_verts = [[0.,0.], [-1., 1], [0.,0.], [0.,2.],[0.,0.], [1, 1]]
>>
>> plot them like...
>>
>> scatter(1,1,s=100, marker=None, verts=arrowup_verts)
>>
>>
>> Can someone make me new verts for the right and left arrow? Then, maybe
>> tomorrow, explain how I was supposed to know what to do.
>
> Draw a line from (0,0) to (-1, -1) on the X-Y plane, and then to (0,0) again, and then continue so forth for all the (x,y) pairs in arrowup_verts. You will notice they form a nice little arrow pointing up. (At some point in this process, you should note that "verts" is short for "vertices". As in vertices of a polygon or poly-line.)
>
> It would seem that the origin of the "verts" coordinate system is translated to the (x,y) data position at which each marker is plotted.
>
> This should give you, I presume, sufficient information to figure out your own left and right arrows, no? Or any other shape you should care to plot...
>
> Zach
>
>
>> Thanks y'all
>>
>> Steven
>>
>> --
>>
>> Steven Boada
>>
>> Doctoral Student
>> Dept of Physics and Astronomy
>> Texas A&M University
>> bo...@ph...
>>
>>
>> ------------------------------------------------------------------------------
>> Precog is a next-generation analytics platform capable of advanced
>> analytics on semi-structured data. The platform includes APIs for building
>> apps and a phenomenal toolset for data science. Developers can use
>> our toolset for easy data analysis & visualization. Get a free account!
>> http://www2.precog.com/precogplatform/slashdotnewsletter
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

--

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

[Matplotlib-users] verts

[Steven B. <bo...@ph...>]

Hey List,

I've got some verts I stole from the internet that draws an upward arrow 
(or a down arrow), but I need to draw an arrow to the right or to the 
left. But I don't really understand verts and how they work.

arrowup_verts = [[0.,0.], [-1., -1], [0.,0.], [0.,-2.],[0.,0.], [1,-1]]
arrowdown_verts = [[0.,0.], [-1., 1], [0.,0.], [0.,2.],[0.,0.], [1, 1]]

plot them like...

scatter(1,1,s=100, marker=None, verts=arrowup_verts)


Can someone make me new verts for the right and left arrow? Then, maybe 
tomorrow, explain how I was supposed to know what to do.

Thanks y'all

Steven

-- 

Steven Boada

Doctoral Student
Dept of Physics and Astronomy
Texas A&M University
bo...@ph...

Re: [Matplotlib-users] "zig-zag" to represent suppressed 0 on axis?

[Francesco M. <fra...@gm...>]

Il giorno 08/apr/2013 21:05, "Kevin Hunter Kesling" <kmh...@nc...> ha
scritto:
>
> At 4:20pm -0400 Sun, 07 Apr 2013, Francesco Montesano wrote:
>>
>> Il giorno 07/apr/2013 21:03, Kevin Hunter Kesling ha scritto:
>>
>>> On the other hand, I'm still such a noob at Matplotlib ... is there
>>> a way to have one of the subplots take up more than its default 50%
>>> allotment?
>>
>>
>> you can give a look at the last two plots in this example
>> http://matplotlib.org/examples/pylab_examples/demo_tight_layout.html or
use
>> plot.axes providing the rectangle that you want
>
>
> That is closer to what I want, but still not there.  I was finally able
to find something that fit the bill to 95% of what I want:
>
>
http://matplotlib.1069221.n5.nabble.com/Proposal-for-Broken-Axes-td38050.html
>
> The first post by 'klukas' does exactly what I asked for.  It's a zig-zag
on the Y-axis to show that what is graphed is not continuous, and unlike
the various "official" examples, the zig-zag placement is user-specifiable,
as opposed to exactly halfway between the top and bottom.
>
> The only thing I have yet to figure out how to do is to simultaneously
have a zig-zag on the X axis as well -- an artifact of how these zig-zags
must be created via multiple axes on the same figure, rather than as built
in to the axis artist.
>
> For googleability:
>
> The above linked graph code enables for matplotlib:
>
>  - suppressed zeros on the Y-axis of an XY plot
>  - showing suppressed data on the Y-axis
>  - lightning bolt symbol on the Y-axis
>  - zig-zag on the Y-axis
>  - a "broken" Y-axis
>
> Thanks for your pointers, Francesco, as they helped me to fine-tune my
Google search terms.  And thank you, Klukas, whoever you are.
>

I'm half that you found the solution for your problem and to have been
useful just providing links. This has been one of the easiest answer I have
ever given :)

And mostly thanks for sharing your findings.

cheers and good night,
Fra

> Cheers,
>
> Kevin