matplotlib-users

[Matplotlib-users] autoscale problem?

[John P. <jo...@ot...>]

Hello,

When I run:

from pylab import *
data = [1.6e-012, 3.0e-012]
plot(data)

the y axis autoscales to 1.8e-12 - 3.2e-12. I get the same behavior when 
I run in interactive mode or save the figure to png.

Does anyone know if this is a bug or if there's something I can do to 
make the autoscaling work out?

Thanks,
John


P.S. Here's the output from the --verbose-helpful flag:

matplotlib data path c:\pyle\python23\share\matplotlib
loaded rc file c:\pyle\python23\share\matplotlib\.matplotlibrc
matplotlib version 0.72.1
verbose.level helpful
interactive is False
platform is win32
numerix numarray 1.2.2
font search path ['c:\\pyle\\python23\\share\\matplotlib']
loaded ttfcache file C:/msys/1.0/home/artsys\.ttffont.cache
backend Agg version v2.2

Re: [Matplotlib-users] autoscale problem?

[Darren D. <dd...@co...>]

Hi John,

It is a bug. I suggest making the following change to ticker.py, starting at 
line 501 in version 0.72.1:

    def le(self, x):
        'return the largest multiple of base <= x'
        d,m = divmod(x, self._base)
        if closeto(m/self._base,1): # was closeto(m, self._base)
            #looks like floating point error
            return (d+1)*self._base
        else:
            return d*self._base

Darren



On Wednesday 16 March 2005 06:26 pm, John Pyle wrote:
> Hello,
>
> When I run:
>
> from pylab import *
> data = [1.6e-012, 3.0e-012]
> plot(data)
>
> the y axis autoscales to 1.8e-12 - 3.2e-12. I get the same behavior when
> I run in interactive mode or save the figure to png.
>
> Does anyone know if this is a bug or if there's something I can do to
> make the autoscaling work out?
>
> Thanks,
> John
>
>
> P.S. Here's the output from the --verbose-helpful flag:
>
> matplotlib data path c:\pyle\python23\share\matplotlib
> loaded rc file c:\pyle\python23\share\matplotlib\.matplotlibrc
> matplotlib version 0.72.1
> verbose.level helpful
> interactive is False
> platform is win32
> numerix numarray 1.2.2
> font search path ['c:\\pyle\\python23\\share\\matplotlib']
> loaded ttfcache file C:/msys/1.0/home/artsys\.ttffont.cache
> backend Agg version v2.2
>
>
>
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-- 

Darren

Re: [Matplotlib-users] autoscale problem?

[Darren D. <dd...@co...>]

On Wednesday 16 March 2005 07:59 pm, Darren Dale wrote:
> I suggest making the following change to ticker.py, starting
> at line 501 in version 0.72.1:
>
>     def le(self, x):
>         'return the largest multiple of base <= x'
>         d,m = divmod(x, self._base)
>         if closeto(m/self._base,1): # was closeto(m, self._base)
>             #looks like floating point error
>             return (d+1)*self._base
>         else:
>             return d*self._base
>

I was testing this bugfix with plot([1.4e-12,3.0e-12]), and noticed that the 
1.4e-12 ticklabel was being dropped.

In ticker.py, I suggest replacing Base.ge with:

    def ge(self, x):
        'return the largest multiple of base >= x'
        d,m = divmod(x, self._base)
        if closeto(m,0) and not closeto(m/self._base,1): return x
        return (d+1)*self._base

The fourth line used to be if m==0: return x, which fails sometimes due to 
floating point inaccuracy. John, remember I was complaining about how certain 
ticklabels wouldnt get rendered in the new scalarformatter I posted a couple 
weeks ago? This was the problem.

Darren

Re: [Matplotlib-users] autoscale problem?

[John P. <jo...@ot...>]

Darren,

This works great for me - thanks!

I should have said this earlier, but matplotlib is excellent! Thank you 
to everyone who works on it.

John

Darren Dale wrote:

>On Wednesday 16 March 2005 07:59 pm, Darren Dale wrote:
>  
>
>>I suggest making the following change to ticker.py, starting
>>at line 501 in version 0.72.1:
>>
>>    def le(self, x):
>>        'return the largest multiple of base <= x'
>>        d,m = divmod(x, self._base)
>>        if closeto(m/self._base,1): # was closeto(m, self._base)
>>            #looks like floating point error
>>            return (d+1)*self._base
>>        else:
>>            return d*self._base
>>
>>    
>>
>
>I was testing this bugfix with plot([1.4e-12,3.0e-12]), and noticed that the 
>1.4e-12 ticklabel was being dropped.
>
>In ticker.py, I suggest replacing Base.ge with:
>
>    def ge(self, x):
>        'return the largest multiple of base >= x'
>        d,m = divmod(x, self._base)
>        if closeto(m,0) and not closeto(m/self._base,1): return x
>        return (d+1)*self._base
>
>The fourth line used to be if m==0: return x, which fails sometimes due to 
>floating point inaccuracy. John, remember I was complaining about how certain 
>ticklabels wouldnt get rendered in the new scalarformatter I posted a couple 
>weeks ago? This was the problem.
>
>Darren
>
>  
>