Improper handling of very large and very small exponents with PyPlot

[stillyslalom]

Axis markers are not especially useful for large-magnitude numbers:

• Insufficient numbers of ticks
• No use of scientific notation
• Lower limit not set to zero when sensible (ymax >> ymin) and padded slightly below

xx = rand(1000) ./ sqrt.(rand(1000))
yy = xx.^(-1)*1e-20
scatter(xx,yy)

Matplotlib's native behavior handles this correctly:

import numpy as np
from numpy.random import rand
import matplotlib.pyplot as plt

xx = rand(1000)/np.sqrt(rand(1000))
yy = (1e-20)*1./xx
plt.plot(xx, yy, "o")

[ChrisRackauckas]

Same as #430

[mkborregaard]

Nicely spotted.

[t-bltg]

Seems fixed.