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Showing results of 77

<< < 1 2 3 4 > >> (Page 3 of 4)
From: Paul B. <ba...@st...> - 2004年02月10日 19:34:44
I occasionally use the scatter() function to make light curves of 
astronomical targets. The scale of the x-axis is often given in days 
with a range of 0.54 - 0.68 days. The y-axis is in counts. This type 
of data produces unusual scatter plots with the blue symbols being very 
elongated ovals (in the x-direction).
Are there plans to change this behavior - maybe by drawing the symbols 
in device space instead of data or user space?
 -- Paul
-- 
Paul Barrett, PhD Space Telescope Science Institute
Phone: 410-338-4475 ESS/Science Software Branch
FAX: 410-338-4767 Baltimore, MD 21218
>>>>> "John" == John Gill <jn...@eu...> writes:
 John> I have some plots I'd like to print out and they would make
 John> better use of the paper if they were done landscape.
 John> Can the postscript backend do this?
Hi John,
I haven't had time to take a close look at this. My initial
suggestions is to experiment with the paper size
import matplotlib
matplotlib.use('PS')
import matplotlib.backends.backend_ps as backend_ps
backend_ps.defaultPaperSize = 11,8.5 # default is 8.5, 11
You may also have to specify a landscape portrait at print time, or
rotate it.
I'll take a closer look later.
JDH
From: John H. <jdh...@ac...> - 2004年02月09日 15:36:08
>>>>> "derek" == derek bandler <d_b...@ho...> writes:
 derek> I am interested in using Matplotlib for real-time
 derek> updating plot applications. My concern is with system load
 derek> issues (they're pretty high). Using the code below, which
 derek> came off of an earlier posting to this list, on a pc (2.4
 derek> gig processor) memory usage ranges from 20 - 50+ megs
 derek> (there's a cycling pattern) and 30-40% of the cpu is being
 derek> used for this basic app. If left to run for 20 minutes or
 derek> so, it seems to crash (entire screen turns grey and reboot
 derek> is required to get machine back to working order).
I answered this problem on the support request you submitted to
sourceforge a couple of days ago. I'll paste in my response from
the sourceforge site
Date: 2004年02月06日 14:22
Sender: jdh2358
Logged In: YES 
user_id=395152
Thanks for the bug report!
I have spent a lot of time optimizing matplotlib for
pltotting and interacting with large data sets, but not for
frequently redrawing small data sets.
Fortunately, I was able to replicate the bug on my system. 
I identified a memory leak in pygtk in a function I use for
rotating tick labels.
It turns out almost all the CPU usuage (and memory) was for
repeatedly computing layout information, rotations, and so
on for text onthe tick labels. Since these rarely change
(eg, in system demo) I cache all the relevant information. 
I also cache the result that is causing the memory leak in
pygtk, so repeated calls will not drain memory.
The result is a system demo with CPU usage reduced from
30-40% to 4-8% and memory consumption reduced from a growing
memory leak to a stable 1.2%.
Not bad. Please let me know if you continue to experience
performance issues. I I have updated CVS. I you have
trouble accessing CVS, email me at
jdh...@ac... and I'll send you a snapshot.
I have no idea about the solaris redraw problem currently
JDH
Date: 2004年02月06日 15:51
Sender: jdh2358
Logged In: YES 
user_id=395152
I tracked down the memory leak in pygtk. I you are
intersting in patching your pygtk, the bug report and patch
are here
http://bugzilla.gnome.org/show_bug.cgi?id=133681
From: derek b. <d_b...@ho...> - 2004年02月09日 15:17:24
<html><div style='background-color:'><DIV class=RTE>
<P>I am interested in using Matplotlib for real-time updating plot applications.&nbsp; My concern is with system load issues (they're pretty high).&nbsp; Using the code below, which came off of an earlier posting to this list, on a pc (2.4 gig processor) memory usage ranges from 20 - 50+ megs (there's a cycling pattern) and 30-40% of the cpu is being used for this&nbsp;basic app.&nbsp; If left to run for 20 minutes or so, it seems to crash (entire screen turns grey and reboot is required to get machine back to working order).</P>
<P>On a solaris machine, the performance numbers are similar, though the memory didn't appear to exceed 30 megs (or cycle).&nbsp; One other solaris&nbsp;issue is that the&nbsp;plot doesn't update, unless it is forced to redraw (by moving another window over the plot window).&nbsp; I've tinkered with the redraw rate, but it didn't seem to help.</P>
<P>Short of the performance issues, this software looks great.&nbsp; Is there a way of using the software that will minimize system impact, or better yet,&nbsp;can this become&nbsp;a development priority?&nbsp; It's not clear if the performance issue is driven by matplotlib, pygtk or gtk.&nbsp; Is it possible that different backends lead to non-trivial differences in&nbsp;performance?&nbsp; </P>
<P>Also, the crashing on a pc and non-updating on solaris are outstanding concerns.</P>
<P>Derek Bandler</P>
<P>####</P>
<P>import pygtk<BR>pygtk.require('2.0')<BR>import gtk<BR>import time<BR>from matplotlib.matlab import *<BR>&nbsp;<BR>def get_memory():<BR>&nbsp;&nbsp;&nbsp; "Simulate a function that returns system memory"<BR>&nbsp;&nbsp;&nbsp; return 100*(1+sin(0.5*pi*time.time()))<BR>&nbsp;<BR>def get_cpu():<BR>&nbsp;&nbsp;&nbsp; "Simulate a function that returns cpu usage"<BR>&nbsp;&nbsp;&nbsp; return 100*(1+sin(0.2*pi*(time.time()-0.25)))<BR>&nbsp;<BR>def get_net():<BR>&nbsp;&nbsp;&nbsp; "Simulate a function that returns network bandwidth"<BR>&nbsp;&nbsp;&nbsp; return 100*(1+sin(0.7*pi*(time.time()-0.1)))<BR>&nbsp;<BR>def get_stats():<BR>&nbsp;&nbsp;&nbsp; return get_memory(), get_cpu(), get_net()<BR>&nbsp;<BR>fig = figure(1)<BR>ax = subplot(111)<BR>ind = arange(1,4)<BR>pm, pc, pn = bar(ind, get_stats())<BR>centers = ind + 0.5*pm.get_width()<BR>pm.set_facecolor('r')<BR>pc.set_facecolor('g')<BR>pn.set_facecolor('b')</P>
<P>ax.set_xlim([0.5,4])<BR>ax.set_xticks(centers)<BR>ax.set_ylim([0,100])<BR>ax.set_xticklabels(['Memory', 'CPU', 'Bandwidth'])<BR>ax.set_ylabel('Percent usage')<BR>ax.set_title('System Monitor')<BR>&nbsp;<BR>def updatefig(*args):<BR>&nbsp;&nbsp;&nbsp; m,c,n = get_stats()<BR>&nbsp;&nbsp;&nbsp; pm.set_height(m)<BR>&nbsp;&nbsp;&nbsp; pc.set_height(c)<BR>&nbsp;&nbsp;&nbsp; pn.set_height(n)<BR>&nbsp;&nbsp;&nbsp; ax.set_ylim([0,100])</P>
<P>&nbsp;&nbsp;&nbsp; fig.draw()<BR>&nbsp;&nbsp;&nbsp; <BR>&nbsp;&nbsp;&nbsp; return gtk.TRUE</P>
<P>gtk.timeout_add(250, updatefig)<BR>show()</P></DIV></div><br clear=all><hr> <a href="http://g.msn.com/8HMBENUS/2752??PS=">Create your own personal Web page with the info you use most, at My MSN.</a> </html>
I have some plots I'd like to print out and they would make better use
of the paper if they were done landscape.
Can the postscript backend do this?
John
From: John H. <jdh...@ac...> - 2004年02月08日 03:24:11
>>>>> "LUK" == LUK ShunTim <shu...@po...> writes:
 >> OK, now we at least know where the problem is. I don't get
 >> such an error message on my system (rhl9, pygtk-2.0.0). What
 >> platform are you on, and what versions of GTK and pygtk are you
 >> running? JDH
 >> 
 LUK> W2K, Enthought python 2.3, pygtk 2.0, gtk 2.0
Hi Luk,
I get the same error message on my WinXP platform. I recently
decoupled the text code from the various backends (gtk, ps, etc). In
the past, each backend specified their own default font, and this is
no longer possible since text is now backend independent. On the
upside, this enables you to save PS or EPS from a GTK or WX GUI
window. On the downside, this exposes the problem that font choosing
is not backend independent. We've talked a number of times about the
importance of this on matplotlib-devel, but haven't done the dirty
work of actually getting it implemented.
So in a nutshell, there is nothing wrong with your setup. We on the
development side just need to spend some time getting fonts
standardized across backends. Ie, we need to agree on a bare minimum
number of fonts with standard names that we can provide on all the
backends, so scripts using these names will work on all the backends.
This is complicated by the fact that most fonts are proprietary, so we
can't ship them or guarantee their existence on a given system.
It's on the list of things to do. If this proves to be a major
impediment for you in the mean time, don't hesitate to bring it up
again. Sometimes those who complain the loudest get their bugs fixed
the soonest.
JDH
From: Nordquest, D. A <NOR...@ga...> - 2004年02月07日 15:53:44
Thanks, John! Funny thing, I, too, recently installed Glade! That's =
it!
Best,
Dave
From: John H. <jdh...@ac...> - 2004年02月07日 03:25:06
>>>>> "Nordquest," == Nordquest, David A <NOR...@ga...> writes:
 Nordquest> BTW, if I do the pygtk test ( >>>import pygtk >>>
 Nordquest> pygtk.require('2.0')
 >>>> import gtk ) once, I get an error message. If I do it again
 >>>> without changing anything, I get no error message.
This reimport situation you describe is expected. If you import a
module a second time, python simply ignores it. So if it failed the
first time, it will fail silently the next times. You should exist
python and start over. The problem you are experiencing is definitely
with gtk and not matplotlib.
In these situations, the best thing to do is go into DOS or a command
shell (Start->Run->command ENTER). Write a little script test.py that
contains only
import pygtk
pygtk.require('2.0')
import gtk
Then go into the shell, an cd into the dir containing test.py.
Manually set your PATH, something like (depends on which windows
platform you are on)
 c:> set PATH=c:\GTK\bin;C:\GTK\lib;C:\Python23;C:\windows\command
 c:> python test.py
I know you've checked your path ad nauseum, but there is still a
decent change is the cause of your problem, 9 times out of 10.
Hey, didn't you solve this once before :-) ? Is this a new platform
for you? Did you reinstall GTK, if so to where? What does
 c:> dir c:\GTK\bin
reveal? I assume you've reread
http://www.async.com.br/faq/pygtk/index.py?req=show&file=faq21.012.htp
100 times.
There is a long thread on the pygtk mailing list where Cousing Stanley
got his gtk corrupted by installing glade, which writes some older
libgtk versions into the windows system dir. Do a file search for
libgtk and make sure nothing shows up outside of your GTK install
tree. Read this thread
http://www.mail-archive.com/py...@da.../msg07324.html, which is
filled with good advice.
Good luck!
JDH
From: John H. <jdh...@ac...> - 2004年02月07日 03:14:17
>>>>> "Peter" == Peter Groszkowski <pgr...@ge...> writes:
 Peter> plot(date_in_some_format, data)
Are the dates strings, python datetime instances, mx datetime
instances, or what?
Here is a thread on python-list you may be interested in
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=mailman.766.1068941179.702.python-list%40python.org&rnum=1&prev=/groups%3Fq%3Dmatplotlib%2Bdate%26ie%3DUTF-8%26oe%3DUTF-8%26hl%3Den%26btnG%3DGoogle%2BSearch
 Peter> I suppose an alternative would be to convert the times to
 Peter> say seconds, create a plot and manually add the actual
 Peter> date/time label (text). This would be tedious but doable.
Currently this is the best way. It would not be too much work to
write a function called plotdate which took, for example, python2.3
datetime instances as the x arg, arbitrary y values, and a datetime
format string as an optional arg, and did all the conversions for you,
set the tick labels, etc... If you want to do it, I think it would be
a nice addition to matplotlib. 
JDH
From: Peter G. <pgr...@ge...> - 2004年02月07日 02:51:20
Hi everyone:
I am interested in plotting data in the form:
2004年01月29日 15:29:17.161621101 5
2004年01月29日 15:29:18.161621061 6
2004年01月29日 15:29:19.161621021 7
2004年01月29日 15:29:20.161620981 8
2004年01月29日 15:29:21.161620941 9
2004年01月29日 15:29:22.161620901 0
2004年01月29日 15:29:23.161620861 1
...
In some cases I will have data every second, other times every minute or 
hour.. and so on..
Ideally I would like the x-axis of my plots to show the time/dates as 
the units. Is this currently possible with matplotlib? So in other words 
could I call on:
plot(date_in_some_format, data)
I suppose an alternative would be to convert the times to say seconds, 
create a plot and manually add the actual date/time label (text). This 
would be tedious but doable.
Thanks.
-- 
Peter Groszkowski Gemini Observatory
Tel: +1 808 974-2509 670 N. A'ohoku Place
Fax: +1 808 935-9235 Hilo, Hawai'i 96720, USA
From: Nordquest, D. A <NOR...@ga...> - 2004年02月07日 00:15:17
I've checked my path several times and all seems to be as it should be. =
However when I try to use pygtk and the latest gtk runtime and =
matplotlib under Win98, I get the following error:
>>> import pygtk
>>> pygtk.require('2.0')
>>> import gtk
>>> from matplotlib.matlab import *
Traceback (most recent call last):
 File "<pyshell#6>", line 1, in -toplevel-
 from matplotlib.matlab import *
 File "D:\PROGRA~1\PYTHON23\Lib\site-packages\matplotlib\matlab.py", =
line 124, in -toplevel-
 from backends import new_figure_manager, error_msg, \
 File =
"D:\PROGRA~1\PYTHON23\Lib\site-packages\matplotlib\backends\__init__.py",=
 line 12, in -toplevel-
 from backend_gtk import \
 File =
"D:\PROGRA~1\PYTHON23\Lib\site-packages\matplotlib\backends\backend_gtk.p=
y", line 15, in -toplevel-
 from gtk import gdk
ImportError: cannot import name gdk
I'm probably overlooking something obvious but would be grateful for =
suggestions.
BTW, if I do the pygtk test ( >>>import pygtk >>> pygtk.require('2.0')
 >>> import gtk ) once, I get an error message. If I do it again =
without changing anything, I get no error message.
Dave
From: John H. <jdh...@ac...> - 2004年02月05日 04:34:13
>>>>> "matthew" == matthew arnison <ma...@ca...> writes:
 matthew> I haven't been using the pan and zoom stuff very much,
 matthew> the issues I described this week are all from initial
 matthew> plots. If I had been doing more zooming then I would have
 matthew> noticed your very good point about jumping ticks being
 matthew> distracting. It's fiddly stuff, but getting it right
 matthew> helps a lot when interpreting results from plots!
OK, I think my approach will be to optimize the number of ticks, tick
locations and view limits on the initial plot and then fix num ticks
for interactive mode (pan/zoom). Ie, the initial guess should be
good, but with interaction, you're on your own. I'll send you some
code when I get this figured out.
 >> Ie, ignore the end point is the default behavior of python.
 matthew> I guessed as much. But I think in this case the python
 matthew> behaviour needs to be over-ridden. Python range logic is
 matthew> generally about integers, arange stretches it, and using
 matthew> this [) style range for plots over-stretches the
 matthew> principle beyond usefulness. There are also a couple of
 matthew> contradictions in matplotlib's behaviour:
Yes, but I can defend myself! From the first line of the homepage 
 matplotlib is a pure python 2D plotting library with a Matlab
 syntax
Ie, matplotlib does contain inherent contradictions because it is both
matlab-like and python-like. matlab has FORTRAN style indexing
(starts with 1) and python has C style indexing (starts with 0). So
the first matplotlib figure starts with figure(1). When using the
matlab interface matplotlib.matlab, I strive for matlab compatibility.
Thus, when you set the axis limits with
 axis([0, 2, -1, -1])
or 
 set(gca(), 'xlim', [0, 2])
I do it like matlab does, ie, endpoints inclusive. 
However, I plead innocence in the case of
 t = arange(0.0, 2.0, 0.1)
 s = sin(2*pi*t)
 plot(t, s)
If the arrays t and s passed to the plot function do not have the
point at t=2.0 defined, "plot" can't guess them. I plot the points
you give me. Note that matplotlib *does* provide the matlab function
"linspace", which returns an evenly sampled array, endpoints included.
So if you want matlab-like behavior you should use matlab-like array
functions (linspace) rather Numeric python array functions (arange) to
define your arrays.
 t = linspace(0.0, 2.0, 20)
 s = sin(2*pi*t)
 plot(t, s)
In a nutshell, with the matlab interface I try to be consistent with
matlab, but there are inconsistencies which arise by virtue of the
fact that it's natural to use python functions (thank god!, that's why
we're all here).
I definitely appreciate the criticism, so feel free to keep at it.
JDH
From: matthew a. <ma...@ca...> - 2004年02月04日 05:26:39
On Tue, 3 Feb 2004, John Hunter wrote:
> So enough excuses! I agree that the current implementation is
> suboptimal and will give it some more thought. Out of curiosity: do
> the undersirable tick locs appear more frequently for you on an
> initial plot or after interacting with the plot.
I haven't been using the pan and zoom stuff very much, the issues I 
described this week are all from initial plots. If I had been doing more 
zooming then I would have noticed your very good point about jumping 
ticks being distracting. It's fiddly stuff, but getting it right helps a 
lot when interpreting results from plots!
> This is a consequence of the way python and Numeric do ranges, and
> doesn't really have anything to do with matplotlib. eg, the Numeric
> function arange
> 
> >>> from Numeric import *
> >>> arange(0.0, 1.0, 0.2)
> array([ 0. , 0.2, 0.4, 0.6, 0.8])
> 
> >>> range(5)
> [0, 1, 2, 3, 4]
> 
> Ie, ignore the end point is the default behavior of python.
I guessed as much. But I think in this case the python behaviour needs to 
be over-ridden. Python range logic is generally about integers, arange 
stretches it, and using this [) style range for plots over-stretches the 
principle beyond usefulness. There are also a couple of contradictions in 
matplotlib's behaviour:
* the axis and tick ranges are inclusive, but the data point range is 
exclusive of the higher end point only
* the auto data range (axis()) is inclusive, but setting it manually is 
exclusive of the higher end point only
Some of this may be alleviated by chooing better tick points. But I think 
it would also be helpful to make whichever behaviour is chosen more 
consistent.
Cheers,
Matthew.
From: John H. <jdh...@ac...> - 2004年02月04日 03:17:23
>>>>> "Jean-Baptiste" =3D=3D Jean-Baptiste Cazier <Jean-Baptiste.cazier@d=
ecode.is> writes:
 Jean-Baptiste> S=E6ll ! I am trying to plot very small number for
 Jean-Baptiste> the Y-axis on semilogy but they do not appear at
 Jean-Baptiste> all unless one of the value is higher Moreover the
 Jean-Baptiste> labels on the Y axis become 0 below 0.001
 >>> semilogy([1.0, 2.3, 3.3],[9.4e-05, 9.4e-05, 9.4e-05]) <-- does
 >>> not work
 Jean-Baptiste> [<matplotlib.lines.Line2D instance at 0x935255c>]
 >>> semilogy([1.0, 2.3, 3.3],[9.4e-04, 9.4e-05, 9.4e-05]) <---
 >>> work
 Jean-Baptiste> [<matplotlib.lines.Line2D instance at 0x940e964>]
S=E6ll Jean!
Thanks for this example. The relevant code which handles autoscaling
is in matplotlib.axis.autoscale_view. I wasn't handling the special
case where min=3Dmax for log scaling (though I do handle it for linear
scaling).
Try this replacement code for axis.py: and the functions decade_down
and decade_up and replace the autoscale_view function.
def decade_down(x):
 'floor x to the nearest lower decade'
 lx =3D math.floor(math.log10(x))
 return 10**lx
def decade_up(x):
 'ceil x to the nearest higher decade'
 lx =3D math.ceil(math.log10(x))
 return 10**lx
class Axis(Artist):
 def autoscale_view(self):
 'Try to choose the view limits intelligently'
 vmin, vmax =3D self.datalim.bounds()
 if self._scale=3D=3D'linear':
 if vmin=3D=3Dvmax:
 vmin-=3D1
 vmax+=3D1
 try:
 (exponent, remainder) =3D divmod(math.log10(vmax - vmin),=
 1)
 except OverflowError:
 print >>sys.stderr, 'Overflow error in autoscale', vmin, =
vmax
 return
 if remainder < 0.5:
 exponent -=3D 1
 scale =3D 10**(-exponent)
 vmin =3D math.floor(scale*vmin)/scale
 vmax =3D math.ceil(scale*vmax)/scale
 self.viewlim.set_bounds(vmin, vmax)
 elif self._scale=3D=3D'log':
 if vmin=3D=3Dvmax:
 vmin =3D decade_down(vmin)
 vmax =3D decade_up(vmax)
 self.viewlim.set_bounds(vmin, vmax)
Let me know how this works for you,
JDH
From: John H. <jdh...@ac...> - 2004年02月04日 03:12:58
>>>>> "matthew" == matthew arnison <ma...@ca...> writes:
 matthew> Hi again, I'm having more trouble with matplotlib ticks
 matthew> today. I wrote a little demo script that illustrates some
 matthew> of the problems:
Hi Matthew,
Thanks for sending me these example scripts - it really helps to have
complete examples when working on these problems. I've made a few
changes to the tickval formatter. The relevant function is
matplotlib.axis.format_tickval and is pretty simple conceptually.
Try replacing the default format_tickval with this one. The d
variable gives the max-min distance of the view limits. I use
different format strings depending on the size of the distance. 
 def format_tickval(self, x):
 'Format the number x as a string'
 d = self.viewlim.interval()
 if self._scale == 'log':
 # only label the decades
 fx = self.transData.func(x)
 isdecade = abs(fx-int(fx))<1e-10
 if self._ticklabelStrings is None and not isdecade: return ''
 #if the number is not too big and it's an int, format it as an
 #int
 if abs(x)<1e4 and x==int(x): return '%d' % x
 # if the value is just a fraction off an int, use the int
 if abs(x-int(x))<0.0001*d: return '%d' % int(x)
 # use exponential formatting for really big or small numbers,
 # else use float
 if d < 1e-2 : fmt = '%1.2e'
 elif d < 1e-1 : fmt = '%1.2f'
 elif d > 1e5 : fmt = '%1.3e'
 elif d > 10 : fmt = '%1.1f'
 elif d > 1 : fmt = '%1.2f'
 else : fmt = '%1.3f'
 s = fmt % x
 #print d, fmt, x, s
 # strip trailing zeros, remove '+', and handle exponential formatting
 m = self._zerorgx.match(s)
 if m:
 s = m.group(1)
 if m.group(2) is not None: s += m.group(2)
 s = s.replace('+', '')
 return s
And then feed it some more of your sadistic examples <wink>. If you
don't like what you see, try tweaking the formats and the distance
values until you get sensible results. Or feel free to provide more
comments and send more examples.
JDH
From: John H. <jdh...@ac...> - 2004年02月04日 03:05:23
>>>>> "matthew" == matthew arnison <ma...@ca...> writes:
 matthew> Hi, I am happily using matplotlib-0.50e. I tried eps
 matthew> output and it worked very nicely. The problem with plot
 matthew> lines not being clipped by a manual axis in the PS
 matthew> backend also seems to have been fixed.
Good to hear ..
 matthew> I have some feedback on the default tick
 matthew> behaviour. matplotlib seems to pick a number of ticks,
 matthew> and then divides through to get the tick values. This
 matthew> results in some ugly long tick labels, making it hard to
 matthew> quickly gauge the range between two points on a graph.
 matthew> E.g. if the y range of a plot is 1.927 to 1.948, then
 matthew> matplotlib puts ticks at (1.927, 1.931, 1.935, ...,
 matthew> 1.948)
I agree this is an important issue. It's also a difficult one. If
matplotlib just had to make a good choice for the axis limits and tick
values for a single plot, it wouldn't be too hard. What becomes
harder is to do this in the presence of interactivity. Once you allow
the user to pan and zoom, you have some other considerations. For
example, if the tick locations or the number of ticks/grids on the
axis move while you pan or zoom, that is visually disturbing. The
easiest way to optimize the tick locations is to have some flexibility
in choosing the number of ticks, but after the initial plot, this
number is set for the rest of the interactive session which makes it
harder.
So enough excuses! I agree that the current implementation is
suboptimal and will give it some more thought. Out of curiosity: do
the undersirable tick locs appear more frequently for you on an
initial plot or after interacting with the plot.
 matthew> Another slight niggle. If I set the axis range manually,
 matthew> then if a data point is exactly equal to the end of the
 matthew> axis range then it won't be plotted. 
This is a consequence of the way python and Numeric do ranges, and
doesn't really have anything to do with matplotlib. eg, the Numeric
function arange
 >>> from Numeric import *
 >>> arange(0.0, 1.0, 0.2)
 array([ 0. , 0.2, 0.4, 0.6, 0.8])
 >>> range(5)
 [0, 1, 2, 3, 4]
Ie, ignore the end point is the default behavior of python.
JDH
From: John H. <jdh...@ac...> - 2004年02月04日 02:55:31
>>>>> "Jean-Baptiste" == Jean-Baptiste Cazier <Jea...@de...> writes:
 Jean-Baptiste> Hi ! I am using with delight the new object_picker
 Jean-Baptiste> tools as of version 0.42b It works fine but I can
 Jean-Baptiste> not find out how to draw the legend, labels, title,
 Jean-Baptiste> etc... Neither the ax (Subplot), nor the fig
 Jean-Baptiste> (ArtistPickerFigure) have those methods. How could
 Jean-Baptiste> I access them ?
First, I recommend upgrading the 0.50 series as there have been APi
changes that affect the object_picker code (the examples.object_picker
demo script is updated). Better to catch up sooner rather than later.
Second, I don't really understand your question. If you want to "draw
the legend, labels, ...", you simply call the draw method. All of
these things (Legend, Text, etc..) are derived from Artist, which
implements a "draw" method. so you can call
 legend.draw()
 label.draw()
and so on?
Then later you say "those methods" using the plural. I don't know
what you mean..... Could you elaborate, and perhaps provide some code
with comments showing where you are stuck?
Thanks,
JDH
From: John H. <jdh...@ac...> - 2004年02月03日 21:42:15
>>>>> "Kuzminski," == Kuzminski, Stefan R <SKu...@fa...> writes:
 Kuzminski> Some notes on compiling GD backend for windows. 1)
 Kuzminski> _gdmodule.c needs to be modified in 2 places to
 Kuzminski> compile on windows
Hi Stephan,
I've been following your instructions on building gdmodule and I've
gotten pretty far. I have a couple of questions for you.
Did you use the prebuilt gd (not gdmodule) or the dll supplied at the
web site. I built it myself, and when I try to build gdmodule, I get
errors like 
_gdmodule.obj : error LNK2001: unresolved external symbol _gdFontGiantRep
_gdmodule.obj : error LNK2001: unresolved external symbol _gdFontLargeRep
The export to these symbols are dependent on the following
preprocessor options (from gd.h)
#ifdef BGDWIN32
#define BGD_EXPORT_DATA_IMPL __declspec(dllexport)
#else
#ifdef WIN32
#define BGD_EXPORT_DATA_IMPL __declspec(dllimport)
#else
/* 2.0.20: should be nothing at all */
#define BGD_EXPORT_DATA_IMPL
#endif /* WIN32 */
#endif /* BGDWIN32 */
In gdfontl.c, there is some code
 BGD_EXPORT_DATA_IMPL gdFontPtr gdFontLarge = &gdFontLargeRep;
I set BGDWIN32 option when building the gd DLL, but I still don't seem
to get _gdFontLargeRep exported to the gd.dll. For example, if I grep
the dll for gdFontLarge, I see that symbol but not gdFontLargeRep.
Ditto for the prebuilt bgd.dll. 
Did you encounter this problem and do you have any insights here?
Thanks,
John Hunter
From: Jean-Baptiste C. <Jea...@de...> - 2004年02月03日 11:46:57
Hi !
I am using with delight the new object_picker tools as of version 0.42b
It works fine but I can not find out how to draw the legend, labels, title,=
 etc...
Neither the ax (Subplot), nor the fig (ArtistPickerFigure) have those metho=
ds.
How could I access them ?
Thanks
Kve=F0ja
Jean-Baptiste
--=20
-----------------------------
Jea...@de...
Department of Statistics
deCODE genetics Sturlugata,8
570 2993 101 Reykjav=EDk
From: matthew a. <ma...@ca...> - 2004年02月03日 03:04:59
Hi again,
I'm having more trouble with matplotlib ticks today. I wrote a little demo 
script that illustrates some of the problems:
...
#!/usr/bin/python
from matplotlib.matlab import *
xx = arange(0.002, 0.0101, 0.001)
print xx
# an instance of yy = rand(9), so all values are between 0 and 1
yy = [ 5.94692328e-04, 1.62328354e-01, 7.56822907e-01, 2.28180047e-02,
 3.23820274e-01, 3.93120900e-01, 6.41332889e-01, 1.22474302e-02,
 5.03485402e-01]
subplot(211)
plot(xx, yy)
subplot(212)
plot(xx, yy)
autoaxis = axis()
print autoaxis
axis(autoaxis)
show()
...
* the x axis includes *two* 0.004 and *two* 0.008; this really worried me 
until I realised it was a cosmetic rounding / significant figures issue, 
however it's bad enough to be seriously misleading. I think the actual 
tick values are something like 0.0036 and 0.0044 but are both rounded to 
0.004.
* the data points lie *between* the x axis ticks, this is a side-effect of 
the above
* the poor choice of tick positions on the y axis -- they should be 
in round numbers like 0.2, 0.4, etc. The most significant varying figure 
should be a multiple of 1, 2, or 5.
* the tick labels should all have the same number of significant figures, 
e.g. 0.00, 0.15, 0.30, 0.45, 0.60, ... for the y axis
* after manually setting the axis (lower subplot), the last point is not 
plotted
I hope you find this feedback useful. I had a go at fixing it in axis.py,
but it's a) fiddly and b) I don't quite understand which part has
precendence when the axis changes during a zoom or pan. Getting the ticks
right depends on the correct bounds for the axis and the choice of
numticks. I noticed you have logic to clean up the bounds (vmin and vmax)
but not the ticklocs.
Thanks for matplotlib.
Cheers,
Matthew.
From: Flavio C. C. <fcc...@ci...> - 2004年02月02日 19:43:34
Hi john,
 After the refactoring you did for version 0.5 I am having a funny 
behavior in a plot embedded in wx:
the frame appers with the size of the toolbar, but if I resize the frame 
the plot is there and is not resizable, it justs stays the same no 
matter the size of the canvas(frame?).
I've made the changes to my original module acording to the revised 
'embedding_in_wx.py' example, which runs fine.
Here is my ploting module:
===============================================
import matplotlib
matplotlib.use('WX')
 
from matplotlib.backends.backend_wx import Toolbar, FigureManager, 
FigureCanvasWx
from matplotlib.figure import Figure
from matplotlib.axes import Subplot
import Numeric as numpy
from RandomArray import *
from MLab import *
from wxPython.wx import *
def create(parent):
 return PlotFigure(parent)
class PlotFigure(wxFrame):
 def __init__(self,parent):
 wxFrame.__init__(self,None,-1,"Results")
 self.fig = Figure((5,4), 75)
 self.canvas = FigureCanvasWx(self,-1,self.fig)
 self.toolbar = Toolbar(self.canvas)
 self.toolbar.Realize()
 # On Windows, default frame size behaviour is incorrect
 # you don't need this under Linux
 tw, th = self.toolbar.GetSizeTuple()
 fw, fh = self.canvas.GetSizeTuple()
 self.toolbar.SetSize(wxSize(fw, th))
 
 # Create a figure manager to manage things
 self.figmgr = FigureManager(self.canvas, 1, self)
 
 # Now put all into a sizer
 sizer = wxBoxSizer(wxVERTICAL)
 # This way of adding to sizer prevents resizing
 #sizer.Add(self.fig, 0, wxLEFT|wxTOP)
 
 # This way of adding to sizer allows resizing
 sizer.Add(self.toolbar, 1, wxLEFT|wxTOP|wxGROW)
 
 # Best to allow the toolbar to resize!
 sizer.Add(self.toolbar, 0, wxGROW)
 self.SetSizer(sizer)
 self.Fit()
 
 def plotLine(self,y, leg, tit='Time Series'):
 """
 Generate line plots
 """
 # Use ths line if using a toolbar
 a = self.figmgr.add_subplot(211)
 
 # Or this one if there is no toolbar
 #a = Subplot(self.fig, 211)
 styles = ('-', '--', ':', '.', 'o', '^', 'v', '<', '>', 's', '+')
 colors = ('b', 'g', 'r', 'c', 'm', 'y', 'k')
 s = 0
 c = 0
 for i in range(numpy.shape(y)[0]):
 if s > len(styles)-1:
 s = 0
 if c > len(colors)-1:
 c = 0
 style = styles[s]
 color = colors[c]
 a.plot(y[i,:],style+color) # plot each line with a different 
combination of color and style
 if c == len(colors)-1:
 s += 1
 c += 1
 a.set_title(tit)
 a.legend(leg)
 self.toolbar.update()
===============================================
which I call like this: (I import the plotting module as PF)
self.fig = PF.create(None)
 leg = self.modict["slabels"]
 tit = 'Time Series and Final State'
 self.fig.plotLine(results, leg, tit)
 
 self.fig.plotBar(results, leg)
 
 self.fig.Show()
From: John H. <jdh...@ac...> - 2004年02月02日 14:57:54
>>>>> "Engelsma," == Engelsma, Dave <D.E...@La...> writes:
Hi David, please post questions directly to the matplotlib-users list.
 Engelsma> Hello -- Is it possible to save figures (I'm using the
 Engelsma> .eps feature) without having to show the plots/charts
 Engelsma> on the user's screen? I'd like to be able to save the
 Engelsma> figures to disk without showing them on the
 Engelsma> screen. Currently, it seems that the figures will not
 Engelsma> save to disk, unless I issue the show() command after
 Engelsma> the savefig. I'd like to eliminate having to call
 Engelsma> show().
From your email, it sounds like you are using the GTK backend and
saving figures with the ps backend. If you just want to save the
figures as PS and not show them to the screen, use the ps backend
directly as described on
http://matplotlib.sourceforge.net/backends.html
 > python myscript.py -dPS
or
 import matplotlib
 matplotlib.use('PS')
 from matplotlib.matlab import *
 t = arange(0.0, 3.0, 0.01)
 for i in range(1,10):
 figure(1)
 s = sin(2*pi*i*t)
 plot(t,s)
 savefig('plot%02d' % i)
 close(1)
In either case, there is no need to call 'show'. If you want to make
multiple figures, you need to clear them between each save, as I did
here by closing the figure.
If you really want to use the GTK backend to make PS figures without
showing the figure, there are some things that will enable this, but I
don't see any reasons to go this route. Let me know.
JDH
From: matthew a. <ma...@ca...> - 2004年02月02日 04:04:20
Hi,
I am happily using matplotlib-0.50e. I tried eps output and it worked very 
nicely. The problem with plot lines not being clipped by a manual axis in 
the PS backend also seems to have been fixed.
...
I have some feedback on the default tick behaviour. matplotlib seems to
pick a number of ticks, and then divides through to get the tick values.
This results in some ugly long tick labels, making it hard to quickly
gauge the range between two points on a graph.
E.g. if the y range of a plot is 1.927 to 1.948, then matplotlib puts
ticks at (1.927, 1.931, 1.935, ..., 1.948)
I think it would be better (and closer to the plotting behaviour of 
other software) if matplotlib picked ticks that were "round", even if that 
means the endpoints of the axes are slightly outside the range of the 
data.
So the ticks for the example above would become:
(1.925, 1.930, 1.935, ..., 1.950)
I guess this would be more complicated to implement than the current 
algorithm, but it would make life easier when interpreting graphs from 
matplotlib!
...
Another slight niggle. If I set the axis range manually, then if a data
point is exactly equal to the end of the axis range then it won't be 
plotted. Making the axis range slightly longer is clumsy. This also 
violates the principle of least surprise, because automatic axis ranges do 
not have this behaviour. A simple way to see the problem is to compare the 
output of the two plots below:
>>> xvals = arange(0.0, 1.0, 0.1)
>>> plot(xvals, [sin(x) for x in xvals])
[<matplotlib.lines.Line2D instance at 0x93fa844>]
>>> show()
>>> plot(xvals, [sin(x) for x in xvals])
[<matplotlib.lines.Line2D instance at 0x9249d2c>]
>>> autoaxis = axis()
>>> autoaxis
[0.0, 0.90000000000000002, 0.0, 0.80000000000000004]
>>> axis(autoaxis)
>>> show()
Presumably the logic for picking the datapoints to plot should use <= not
<.
Cheers,
Matthew.
From: John H. <jdh...@ac...> - 2004年02月01日 16:44:40
>>>>> "Flavio" == Flavio Codeco Coelho <fcc...@ci...> writes:
 Flavio> Hi John, What do you think of adding a button to the
 Flavio> standara toolbar allowing the plotted data to be save in
 Flavio> CSV format?
My initial thought is this would be hard to do well. Axes can contain
an arbitrary combination of lines, text and patches (of which there
are many types). The lines can be different lengths. The plot can
contain an arbitrary number of axes. How to export these in a
meaningful way so that the code on the other side can load and use it
is not clear to me.
Perhaps you should write a function 
 def line_to_csv(l, fname):
 # export the x and y line data to csv
likewise you may want
 def hist_output_to_csv(args) 
and call these functions from your python script as necessary. Take a
look at the file examples/object_picker.py (requires gtk backend),
where you can select an individual line with the mouse. It wouldn't
be hard to plug an export to csv function together with this picker
functionality.
But it seems that for the most part these are specialized use cases
that may be better handled on your end by writing your own functions
and subclassing the NavigationToolbar to add your own buttons (easy to
do, I can provide some example code if you like) because I suspect
there would be little agreement about what export functionality is
desirable.
 Flavio> Talking about plots, I am writing a module to calculate
 Flavio> Kernel density estimates (a kind of continuous histogram)
 Flavio> would you be interested in adding it to matplotlib?
Please send me the module code and some demo script and I'll take a
look. I'm happy to include useful numerical and statistical code in
matplotlib.mlab or wherever appropriate. Maybe a few online
references where I can read about kernel density estimates too...
Thanks!
JDH
From: John H. <jdh...@ac...> - 2004年02月01日 16:33:06
>>>>> "Nils" == Nils Wagner <nw...@me...> writes:
 Nils> ~/cvs/matplotlib/htdocs/screenshots> /usr/bin/python
 Nils> makeshots.py Making screenshot simple_plot.py Traceback
 Nils> (most recent call last): File "simple_plot.py", line 1, in ?
 Nils> from matplotlib.matlab import * File
 Nils> "/usr/local/lib/python2.1/site-packages/matplotlib/matlab.py",
 Nils> line 109, in ? from mlab import * File
 Nils> "/usr/local/lib/python2.1/site-packages/matplotlib/mlab.py",
 Nils> line 147 else: numFreqs = NFFT//2+1 ^ SyntaxError: invalid
 Nils> syntax
matplotlib requires python2.2, which supports 
 from __future__ import division
That line should be the on or near the first code line of
matplotlib/mlab.py. When this is imported, the integer division //
operator is defined.
See what's new in python2.2
http://www.python.org/doc/2.2.3/whatsnew/node7.html
I'm surprised you didn't get an error on the call to
from __future__ import division.
JDH
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