histogram with log scale has display issues for small values #191

MarcoFalke · 2017-07-02T09:39:57Z

It seems matplotlib can not properly render histograms, when log scale is active for the y-axis and the absolute frequency is smaller than ~2.7, ie. 1 and 2.

The Python code:

import pandas as pd
import matplotlib.pyplot as plt
from matplotlib2tikz import save as tikz_save

plot_values = pd.DataFrame(
    {
        'test0': pd.Series([0, 0, 0, .1, .1, .2]),
        'test1': pd.Series([0, .1]),
    }
)
plot_values.plot.hist(stacked=False)  # Should not use stacked for log plot
plt.gcf().set_size_inches(4, 3)
plt.yscale('log')
plt.ylim(ymin=.1)

plt.savefig('/tmp/test_a.png')
tikz_save('/tmp/test_a.tikz')

The png looks fine:

However, from the pdf it seems histogram bars are plotted with their lower bound starting at ~2.7 (instead of -inf). This will especially cause issues when the frequency is 1 or 2.

nschloe · 2019-03-21T12:44:01Z

Can you cook up an example code without pandas? It's such a heavy dependency...

nschloe / tikzplotlib

histogram with log scale has display issues for small values #191

histogram with log scale has display issues for small values #191

MarcoFalke commented Jul 2, 2017 •

edited

nschloe commented Mar 21, 2019

nschloe / tikzplotlib

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histogram with log scale has display issues for small values #191

histogram with log scale has display issues for small values #191

Comments

MarcoFalke commented Jul 2, 2017 • edited

nschloe commented Mar 21, 2019

MarcoFalke commented Jul 2, 2017 •

edited