I'm plotting values that cover a very small range with a relatively
large base, e.g.
In practice, the data series hovers at a single value for several
hundred elements in a row, then fluctuates slightly. Initially
matplotlib does what I expect, and the Y-axis ticks are labeled 373,
374, 376, 376, etc. Once the small fluctuations are plotted, however,
it switches to showing relative values, with the absolute reference
point above the plot, as in the attached image. This is needlessly
confusing - is there a way to prevent such behavior?