st: Formula/algorithm Stata uses to calculate default axis ranges and tick marks?

[Michael Stepner <michaelstepner@gmail.com>]

Hello,

I'm trying to find a description of the formula or algorithm Stata
uses to set the default look of a scatter plot's axes: how it chooses
the default range and tick marks.  I've searched online and in the
Stata manual, but haven't found any details.  I've read that Stata
chooses approximately 5 "nice values" for the tick marks, but haven't
found any indication of how those "nice values" are selected.

If anyone could point me to a detailed description of the methodology
for selecting the nice defaults, it would be greatly appreciated!
Even if it's just pointing me to some code where these defaults are
calculated and implemented, that would be a great help.

Thank you,
Michael Stepner
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