matplotlib/matplotlib — pull request #3014 by tacaswell (2014-04-27 21:42:31+00:00)
Title: BUG : improved input clean up in Axes.{h|v}line

- passing in a (N, 1) shaped array as input causes the zipping to
generate an extra dimension
- use squeeze to get rid of useless dimensions
- use atleast_1d to make sure scalars remain 1D ((1, ) vs () shape)
- closes #2197

@efiring I suspect there is a better way to do this.