pcolormesh actually requires the X,Y to be +1 size of the data array

Kind of ran into an unexpected quirk with pcolormesh that perhaps could be improved to save users like me from themselves!

The X, Y arrays to this function need to be 1 larger than the data array so that the bounds of the grid cell are known. Matplotlib's code silently trims the array and will drop the rightmost column and top row.

The examples/plotsst.py suffers from this issue as X,Y,data are all (720, 1440), so the plot is not complete.

I am not sure what to suggest for a fix to this, perhaps simply documenting it is sufficient or maybe basemap should complain when this happens? If you think I should take my whining upstream to matplotlib, that's understandable :)

thank you.

Start with examples/plotsst.py and inspect how its X, Y, and data arrays are passed to pcolormesh. Compare the example's dimensions with the pcolormesh expectations described in the issue, then determine whether the project should document the requirement or report mismatched dimensions. Done means the example no longer silently omits its top row and rightmost column, with the chosen behavior documented or enforced.