What could cause a plot fail in my code?

[Peter Pearson]

On Mon, 21 Dec 2015 09:29:24 -0800 (PST), Robert <rxjwg98 at gmail.com> wrote:
> On Monday, December 21, 2015 at 12:15:54 PM UTC-5, Robert wrote:
>> Hi,
>> 
>> I find a useful code snippet on link:
>> 
>> http://stackoverflow.com/questions/25126444/logistic-regression-in-pymc/34400966#34400966
>> 
>> but it has error on plot function. The error message is as following:
>> ---------
>> %run "C:\Users\rj\pyprj\logic_regression0.py"
>> [-----------------100%-----------------] 10000 of 10000 complete in 12.6       secPlotting beta0
>> Plotting tau
>> Plotting betaSalad
>> Plotting sigma
>> ---------------------------------------------------------------------------
>> UnboundLocalError                         Traceback (most recent call last)
>> C:\Users\pyprj\logic_regression0.py in <module>()
>>      34 #m.sample(100000, 50000, 50)
>>      35 m.sample(10000, 5000, 50)
>> ---> 36 pm.Matplot.plot(m)
>>      37 import matplotlib.pyplot as plt
>>      38 #plt.plot(m)
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site- packages\pymc\Matplot.pyc in wrapper(pymc_obj, *args, **kwargs)
>>     339                     if args:
>>     340                         name = '%s_%s' % (args[0], variable.__name__)
>> --> 341                     f(data, name, *args, **kwargs)
>>     342             return
>>     343         except AttributeError:
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pymc\Matplot.pyc in plot(data, name, format, suffix, path,  common_scale, datarange, new, last, rows, num, fontmap, verbose)
>>     453             num=num * 2,
>>     454             last=last,
>> --> 455             fontmap=fontmap)
>>     456 
>>     457         if last:
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pymc\Matplot.pyc in wrapper(pymc_obj, *args, **kwargs)
>>     375 
>>     376         # If others fail, assume that raw data is passed
>> --> 377         f(pymc_obj, *args, **kwargs)
>>     378 
>>     379     wrapper.__doc__ = f.__doc__
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\pymc\Matplot.pyc in histogram(data, name, bins, datarange, format, suffix, path, rows, columns, num, last, fontmap, verbose)
>>     576 
>>     577         # Generate histogram
>> --> 578         hist(data.tolist(), bins, histtype='stepfilled')
>>     579 
>>     580         xlim(datarange)
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\matplotlib\pyplot.py in hist(x, bins, range, normed, weights, cumulative, bottom, histtype, align, orientation, rwidth, log, color, label, stacked, hold, data, **kwargs)
>>    2956                       histtype=histtype, align=align, orientation=orientation,
>>    2957                       rwidth=rwidth, log=log, color=color, label=label,
>> -> 2958                       stacked=stacked, data=data, **kwargs)
>>    2959     finally:
>>    2960         ax.hold(washold)
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\matplotlib\__init__.py in inner(ax, *args, **kwargs)
>>    1809                     warnings.warn(msg % (label_namer, func.__name__),
>>    1810                                   RuntimeWarning, stacklevel=2)
>> -> 1811             return func(ax, *args, **kwargs)
>>    1812         pre_doc = inner.__doc__
>>    1813         if pre_doc is None:
>> 
>> C:\Users\AppData\Local\Enthought\Canopy\User\lib\site-packages\matplotlib\axes\_axes.py in hist(self, x, bins, range, normed, weights, cumulative, bottom, histtype, align, orientation, rwidth, log, color, label, stacked, **kwargs)
>>    6192                         ymin = np.amin(m[m != 0])
>>    6193                         # filter out the 0 height bins
>> -> 6194                 ymin = max(ymin*0.9, minimum) if not input_empty else minimum
>>    6195                 ymin = min(ymin0, ymin)
>>    6196                 self.dataLim.intervaly = (ymin, ymax)
>> 
>> UnboundLocalError: local variable 'ymin' referenced before assignment 
>> /////////////
>> 
>> I have no clue at all on debug it. Could you help me?
>> Thanks,
>
> Excuse me. The code link should be this one:
>
> http://nbviewer.ipython.org/gist/aflaxman/8329ec1b9f861469f896
>
> Do you experience such errors?


>From a quick look, it appears that you are trying to plot a histogram
in which all the bins are empty.


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