matplotlib-users

[Matplotlib-users] semilogy

[Jean-Baptiste C. <jea...@de...>]

Saell

I have got problem using semilogy while semilogx works fine
I with matplotlib with python2 on RedHat 9.0 default setup
Any idea of what is going wrong ?



Below is the code I use in the interactive2 mode:

Takk
Kve=C3=B0ja

Jean-Baptiste


Welcome to matplotlib.

    help(matplotlib) -- shows a list of all matlab compatible commands
provided
    help(plotting) -- shows a list of plot specific commands

>>> import matplotlib
>>> from matplotlib.matlab import *
pygtk.require() must be called before importing gtk
matplotlib requires pygtk-1.99.16 or greater -- trying anyway.  Please
hold on
>>> from matplotlib.backends.backend_gtk import ShowOn
>>> ShowOn().set(1)  # turning on interactive mode
>>> dt=3D0.01
>>> t=3Darange(dt,10.0,dt)
>>> semilogy(t,t)
Traceback (most recent call last):
  File "<<console>>", line 1, in ?
  File "/usr/lib/python2.2/site-packages/matplotlib/matlab.py", line
829, in semilogy
    try: ret =3D  gca().semilogy(*args, **kwargs)
  File "/usr/lib/python2.2/site-packages/matplotlib/axes.py", line 2007,
in semilogy
    l =3D selfplot(*args, **kwargs)
NameError: global name 'selfplot' is not defined
>>> semilogx(t,t)
[<matplotlib.lines.Line2D instance at 0x8516034>]
>>>=20

[Matplotlib-users] semilogy

[Neal B. <ndb...@gm...>]

I want to plot semilogy with major and minor grid.  I tried:

plt.grid(which='both')

But 2 problems:

1) For semilogy, most of my viewers will expect to see 10 minor ticks/major 
tick.  I got 5.  How do I change it?

2) I'd like the major ticks to be solid lines, and minor ticks to be dashed.  I 
got all dashed.

Re: [Matplotlib-users] semilogy

[Paul I. <piv...@gm...>]

Neal Becker, on 2011-01-05 08:19,  wrote:
> I want to plot semilogy with major and minor grid.  I tried:
> 
> plt.grid(which='both')
> 
> But 2 problems:
> 
> 1) For semilogy, most of my viewers will expect to see 10 minor
> ticks/major tick.  I got 5.  How do I change it?

Hi Neal,

odd, it works here. (See attached image)

In [1]: plt.semilogy(((np.random.rand(50)*9+1)))

If your problem persists, can you provide a small example where
this does not work?  You might check the minor locator -  make
sure that it is base 10

In [2]: plt.gca().yaxis.minor.locator._base
Out[2]: 10.0

> 2) I'd like the major ticks to be solid lines, and minor ticks
> to be dashed.  I got all dashed.

In [3]: plt.grid(which='major', linestyle='solid')
In [4]: plt.grid(which='minor', linestyle='dashed')

-- 
Paul Ivanov
314 address only used for lists,  off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7 

Re: [Matplotlib-users] semilogy

[Neal B. <ndb...@gm...>]

Paul Ivanov wrote:

> Neal Becker, on 2011-01-05 08:19,  wrote:
>> I want to plot semilogy with major and minor grid.  I tried:
>> 
>> plt.grid(which='both')
>> 
>> But 2 problems:
>> 
>> 1) For semilogy, most of my viewers will expect to see 10 minor
>> ticks/major tick.  I got 5.  How do I change it?
> 
> Hi Neal,
> 
> odd, it works here. (See attached image)
> 
> In [1]: plt.semilogy(((np.random.rand(50)*9+1)))
> 
> If your problem persists, can you provide a small example where
> this does not work?  You might check the minor locator -  make
> sure that it is base 10

Perhaps because my data covered a large range 10**-7 ... 10**0?  I'll try some 
experiments.  I had to force it with:

fig.get_axes()[0].set_yticks ([a*(10**b) for b in xrange (-7,0) for a in xrange 
(1,10) ], minor=True)

> In [2]: plt.gca().yaxis.minor.locator._base
> Out[2]: 10.0
> 
>> 2) I'd like the major ticks to be solid lines, and minor ticks
>> to be dashed.  I got all dashed.
> 
> In [3]: plt.grid(which='major', linestyle='solid')
> In [4]: plt.grid(which='minor', linestyle='dashed')
> 

Re: [Matplotlib-users] semilogy

[John H. <jdh...@ac...>]

>>>>> "Jean-Baptiste" == Jean-Baptiste Cazier <jea...@de...> writes:

It's a bug that somehow escaped our poor-man's regression testing
suite.

line 2007 in /usr/lib/python2.2/site-packages/matplotlib/axes.py
should read

    l = self.plot(*args, **kwargs)
            ^
not 

    l = selfplot(*args, **kwargs)

Thanks for the report!

JDH