[Matplotlib-users] symlog iffy when range max is below 1e0=1

[Liang Wang]

Hi,

I have a problem using 'symlog' when the range maximum is below 1e0=1.
Perhaps I'm misusing it, possibly the linthresh option.

Example notebook:
https://gist.github.com/liangwang0734/fde9a033c3d8788075589e2f9fd87f0c

Sample code:
import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

def test(start):
    linthresh = 10**(start+1)
    tmp = np.logspace(start, start + 3, 20)
    tmp = np.hstack((-tmp[::-1], tmp))

    fig, ax = plt.subplots()
    ax.plot(tmp, marker='o')
    ax.set_yscale('symlog', linthresh=linthresh)
    ax1 = ax.twinx()
    ax1.plot(tmp, c='orange', ls='--')

test(0)  # OK, linear scale and symlog scale look different
test(-3) # iffy, linear scale and symlog scale look the same

[image: image.png]

[image: image.png]
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