Re: [matplotlib-devel] log in hist() and toggling

[Manuel M. <mm...@as...>]

John Hunter wrote:
> On Sat, May 24, 2008 at 6:02 PM, Olle Engdegård <ol...@fy...> wrote:
> 
>> I very much miss the 'l' shortcut for toggling log/lin y-scale in the
>> trunk! I use it a lot.
>>
>> I suggest restoring it with something like
>>
>> if self.get_yscale() is ("log" or "linear"):
>>    self.toggle_log_lineary()
>> else: pass
>>
>> I think most of time most people use log or linear scales.
> 
> 
> This seems reasonable, but when I tried to implement it it looked like
> the nan mask for the simple_plot.py example was sticky, eg when I
> toggled back to linear the negative values were still masked.  I tried
> a simpler example still (all positive y data) and got something very
> strange: the plotted y values appear to change on a toggle from log
> and back to linear:
> 
> In [18]: import matplotlib.pyplot as plt
> 
> In [19]: plt.close('all')
> 
> In [20]: ax = plt.subplot(111)
> 
> In [21]: ax.plot(np.random.rand(20))
> Out[21]: [<matplotlib.lines.Line2D object at 0x123082f0>]
> 
> In [22]: ax.set_yscale('linear'); ax.figure.canvas.draw()
> 
> In [23]: ax.set_yscale('log'); ax.figure.canvas.draw()
> 
> In [24]: ax.set_yscale('linear'); ax.figure.canvas.draw()  # the y
> data are now plotted differently
> 
> 
> I am not sure what is going on yet, but I'm sure Michael will chime in
> since I think we are seeing some funkiness in the new transforms and
> path infrastructure.
> 
> 
>> The new hist() function looks really good, I especially welcome the "step"
>> mode. A couple of comments:
>>
>> The latest svn incarnation doesn't allow for log scale in step-mode
>> (unless you set it manually).
>>
>> Also, I think the step-mode should have fill=False as default, otherwise
>> it does not look that much different from bar-mode. The nice thing about
>> step histograms is that you can put several of them in the same plot while
>> keeping it intelligible!
> 
> Manuel is the developer behind these nice new changes to hist --
> hopefully he can help you here.

log-scale support for step-histograms is done now on the trunk.

   Manuel