[matplotlib-devel] adding second formatter/locater set to axes objects

[Thomas C. <tca...@gm...>]

A question I have seen go by twice on SO is how to add a tick marks to
the top/right of a plot which are re-scaled version of the values on
the bottom/lefit axis (ex km/h on the left and mph on the right).  My
understanding of the best way to do this is to use twin* and then keep
the range of the two axes in sync by hand.

I am proposing adding at set of alternate formatters/locators to the
`axis` objects which if they exist are used for the top/right labels.
Before I dive too deep into this, I want to check that a) there isn't
a better way to do this that I do not know and b) if this sounds like
a reasonable approach.

Tom

--
Thomas Caswell
tca...@gm...