xmax, etc. type commands

I find the following definitions really useful: def

    > xmin(val): a = axis() a[0]=val axis(a) return

    > def xmax(val): a = axis() a[1]=val axis(a) return

    > def ymin(val): a = axis() a[2]=val axis(a) return

    > def ymax(val): a = axis() a[3]=val axis(a) return

I'm not real keen on adding four new names to the pylab interface for
such a small convenience. This has nothing to do with matlab
compatibility, but just to try and limit the number of different
functions that mostly do the same thing. Already we have axis, xlim,
ylim, and ax.set_xlim, etc. Adding more different functions to set
the limits is a recipe for complexity and confusion.

I think there is a solution for you though by extending the functions
already in place, which would entail just a little more typing. One
possibility would be to allow kwargs to axis or xlim/ylim, so that you
could do

  axis(xmin=2)

and it would just update the xmin while keeping all other args the
same.

Alternatively, that interface could be expose in xlim/ylim

  xlim(xmin=2)

What do you think?

JDH