matplotlib-users Mailing List for matplotlib

On 9/1/05, Eric Emsellem <ems...@ob...> wrote:
> I am trying to use hlines and vlines but there seems to be an
> "asymmetry" in these 2 commands.
>
> ==> hlines accept "fmt" as a keyword, but vlines does NOT seem to accept it.
>
> Any reason why this is so? (I want to draw a small dashed line across
> part of my plot)
Just a bug -- I just updated CVS to unify the hlines and vlines
arguments. Both now take a fmt argument, as well as optional kwargs
that are passed on to Line2d. So you can do, for example
 vlines(x, ymin, ymax, fmt='b--', linewidth=2)
and likewise for hlines
axes.py revision: 1.134 .
Thanks,
JDH

>>>>> "Achim" == Achim Gaedke <Ach...@ph...> writes:
 Achim> Hello! I'd like to plot some errorbars, removing them and
 Achim> again plot new ones or just supply new coordinates. So now
 Achim> I know how to draw errorbars, but I could not find a
 Achim> set_yerrdata function or how to remove all the lines,
 Achim> returned from errorbar method.
You can remove any line from the axes with
 ax.lines.remove(line)
errorbar returns (yline, errlines) and so if for example you want to
remove all the err lines
yline, errlines = errorbar(t, s, e, f, fmt='o')
for line in errlines:
 ax.lines.remove(line)
and then force a redraw as desired.
JDH

>>>>> "Alan" == Alan G Isaac <ai...@am...> writes:
 Alan> Unlike 'plot', 'plot_date' does not completely honor the
 Alan> linestyle specification if given in a dictionary. Try this:
 Alan> import pylab l=dict(linestyle='-')
 Alan> pylab.plot_date([100000,200000,300000],[1,2,3],**l)
 Alan> You will see points as well as lines plotted. I suspect a
 Alan> small bug here?
There is a slight inconsistency in that plot_date and plot have
different default behavior, you can control the plot_date marker with
the dictionary; note that the linestyle and marker are independent
line properties.
 # use no marker
 l=dict(linestyle='-', marker=None)
 # use a square marker
 l=dict(linestyle='-', marker='s')
JDH

Unlike 'plot', 'plot_date' does not completely honor
the linestyle specification if given in a dictionary.
Try this:
import pylab
l=dict(linestyle='-')
pylab.plot_date([100000,200000,300000],[1,2,3],**l)
You will see points as well as lines plotted.
I suspect a small bug here?
Thanks,
Alan Isaac
using 0.83.2

Hi John,
thank you very much for your quick reply!
It seems things are slightly more complicated, though...
On Thu, 1 Sep 2005, John Hunter wrote:
> On 9/1/05, Arnd Baecker <arn...@we...> wrote:
>
> > today I urgently needed to plot a matrix in a given
> > region of a plot. It seems that imshow does not
> > support this (at least I could not find how)
> > and I don't understand the internals well
> > enough to add such a feature.
> > As work-around I have set up the quick hack listed
> > at the end of this mail.
> > It is not really complicated, but
> > maybe it is useful to someone else.
>
> If I'm understanding you correctly, you want to set the "extent"
> argument of imshow
Well, I thought so too, but I also need `axis("equal")`
and depending on the order of setting the
axis intervals (`axis([-0.35,2.1,-0.2,1.25])`)
before or after this, one obtains completely different results.
Below is an example, where this is illustrated,
by changing the code at the places marked by ===>.
So the example I posted was stripped down too strongly
(and your solution does work for that case!).
Best,
Arnd
P.S.: I ran my test with yesterdays CVS.
###################
from pylab import *
# ===> uncommenting this gives a different result:
#ax=subplot(111,autoscale_on=False)
# ===> changing the order of these two gives different results:
axis("equal")
axis([-0.35,2.1,-0.2,1.25])
 # (note that -0.2 and 1.25 are not respected)
arr=reshape(arange(25),(5,5))
# ===> commenting this one out, when autoscale_on=False
# gives the expected result
imshow(arr, extent=[0.5,1.0,0.2,0.8])
# plot a circle to see if the aspect ratio is correct:
phi=arange(0.0,2.0*pi,0.01)
x=0.5*cos(phi)+0.5
y=0.5*sin(phi)+0.5
plot(x,y,lw="8")
show()

	I don't have a mac accessible to me right now, but are you using python or 
pythonw? You can/should actually use the python command with the CocoaAgg. 
Multiple figures is the big problem right now, but simple cases have seemed to 
work fine.
- Charlie
Rob Hetland wrote:
> 
> I just tried out your developing CocoaAgg backend for matplotlib. I am 
> very excited to get this working -- I think it is a great idea. 
> Unfortunately, I am getting an error ending with when I import pylab:
> 
> [....]
> File "/Library/Frameworks/Python.framework/Versions/2.4/lib/ 
> python2.4/site-packages/PyObjC/PyObjCTools/NibClassBuilder.py", line 
> 150, in _extractClassesFromNibFromBundle
> raise NibLoaderError, ("Could not find nib named '%s' "
> PyObjCTools.NibClassBuilder.NibLoaderError: Could not find nib named 
> 'Matplotlib.nib' in bundle 'NSBundle </Library/Frameworks/ 
> Python.framework/Versions/2.4/share/matplotlib> (not yet loaded)'
> 
> Any ideas?
> 
> -Rob
> 
> 
> -----
> Rob Hetland, Assistant Professor
> Dept of Oceanography, Texas A&M University
> p: 979-458-0096, f: 979-845-6331
> e: he...@ta..., w: http://pong.tamu.edu
> 

On 9/1/05, Arnd Baecker <arn...@we...> wrote:
 > today I urgently needed to plot a matrix in a given
 > region of a plot. It seems that imshow does not
 > support this (at least I could not find how)
 > and I don't understand the internals well
 > enough to add such a feature.
 > As work-around I have set up the quick hack listed
 > at the end of this mail.
 > It is not really complicated, but
 > maybe it is useful to someone else.
If I'm understanding you correctly, you want to set the "extent"
argument of imshow
from pylab import *
arr=3Dreshape(arange(25),(5,5))
imshow(arr, extent=3D[5.0,8.0,15.0,50.0])
x=3Darange(2.0,10.0,0.1)
line1,=3Dplot(x,x**2)
line2,=3Dplot(x,x**2)
setp(line2,data=3D(x,0.25*x**3),zorder=3D1000)
show()
 > Note, that there are a couple of problems:
 > - zooming does not work as expected
 > (the displayed matrix stays fixed in absolute coords wrt to
 > the current graph)
 > - drawing a line over the shown bitmap is not possible
 > - presumably more
The approach above should fix these three problems.
JDH

Hi,
today I urgently needed to plot a matrix in a given
region of a plot. It seems that imshow does not
support this (at least I could not find how)
and I don't understand the internals well
enough to add such a feature.
As work-around I have set up the quick hack listed
at the end of this mail.
It is not really complicated, but
maybe it is useful to someone else.
Note, that there are a couple of problems:
- zooming does not work as expected
 (the displayed matrix stays fixed in absolute coords wrt to
 the current graph)
- drawing a line over the shown bitmap is not possible
- presumably more
Is there a way to this better with imshow?
Best,
Arnd
#########################
from pylab import *
def plot_mat(mat,extent=None):
 """ Plot a matrix (or whatever suits imshow) at
 the place defined by extent=[x0,x1,y0,y1].
 """
 g=gca()
 l,b,w,h=g.get_position()
 x0,x1=g.get_xlim()
 y0,y1=g.get_ylim()
 #print "Axes coords of curr axes:",l,b,w,h
 #print "Ranges:",x0,x1,y0,y1
 if extent!=None:
 inset_x0=extent[0]
 inset_x1=extent[1]
 inset_y0=extent[2]
 inset_y1=extent[3]
 else:
 inset_x0=x0
 inset_x1=x1
 inset_y0=y0
 inset_y1=y1
 #print "WANTED:",inset_x0,inset_x1,inset_y0,inset_y1
 inset_w=w*(inset_x1-inset_x0)/(x1-x0)
 inset_h=h*(inset_y1-inset_y0)/(y1-y0)
 inset_l=l+(inset_x0-x0)/(x1-x0)*w
 inset_b=b+(inset_y0-y0)/(y1-y0)*h
 #print "RESULT:",inset_l , inset_b , inset_w , inset_h
 ax=axes( [inset_l , inset_b , inset_w , inset_h],axisbg="y")
 setp(ax,xticks=[],yticks=[])
 imshow(arr,interpolation="nearest")
# 2D
arr=reshape(arange(25),(5,5))
# 1D plot
x=arange(2.0,10.0,0.1)
line1,=plot(x,x**2)
line2,=plot(x,x**2)
#draw()
plot_mat(arr,extent=[5.0,8.0,15.0,50.0])
# Problem: try to plot this over the other plot,
# does not work
setp(line2,data=(x,0.25*x**3),zorder=1000)
show()

Hello!
I'd like to plot some errorbars, removing them and again plot new ones
or just supply new coordinates.
So now I know how to draw errorbars, but I could not find a set_yerrdata
function or how to remove all the lines, returned from errorbar method.
Yours, Achim

Hi,
I am trying to use hlines and vlines but there seems to be an 
"asymmetry" in these 2 commands.
==> hlines accept "fmt" as a keyword, but vlines does NOT seem to accept it.
Any reason why this is so? (I want to draw a small dashed line across 
part of my plot)
thanks
Eric
-- 
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