Re: [Matplotlib-users] drawing secondary x axis for months: a better way?

[Mike K. <mc...@gm...>]

On 10/8/12 11:03 PM, Paul Tremblay wrote:
> I often have to make graphs with time series, with each point being the
> start of a week. Below is the result I wish:
>
> However, in order to make the secondary x axis the the month labels, I
> need something like 40 lines of code. My strategy consists in first
> drawing the rates in the normal way and using matplotlib's dateFormatter
> to set the week numbers. That part is easy.
>
> In order to draw the x axis below to show when the weeks occur, I draw
> two more lines, and makes these lines invisible. The first line has as
> the x points the start of each month, and the y values as the
> corresponding rate. The second line has as its x value the middle of
> each month, with the corresponding y value.
>
> Below is my code. I have to use such a graph quite often--so often, in
> fact, that if I don't find an easier way to make the secondary x axis, I
> will store the code in my own library for re-use. Does anyone know of a
> simpler, more elegant way?
>

Don't have time to prove that I can reproduce what you want, but
try parasite axes with axes_grid1: the example is for one on the 
right-hand side, but I think it'll do what you want.

http://matplotlib.org/mpl_toolkits/axes_grid/users/overview.html#axisartist-with-parasiteaxes

M