PLOT,/ISOTROPIC bug..

[steinhh(at)ulrik.uio.no (Stein Vidar Hagfors Haugan)]

In astronomy, we often have a weird outlook on the sky, that
results in using weird coordinate systems - sky positions are
usually measured as positive in the directions East and
North. Now, if this stuff was on the surface of the Earth, it
would mean "more East equals more to the right", but when you turn
around and look at the sky, it becomes "more East equals more to
the left", so we have a "positive X" pointing left....

Ok, I can live with that (guess I'll have to :-), I just use an
inverted XRANGE when plotting. However, the recently added (and
very useful!) ISOTROPIC keyword in PLOT doesn't cope too well -
try:

IDL> plot,[0,1],[0,1],xrange=[1,-1],yrange=[-1,1],/isotropic

Whee! Where did my plot go :-)

So, RSI, remember that *isotropy* means "all coordinates
are equal", but do remember that "some coordinates are more
equal than others" :-)

I don't blame RSI for making this mistake, but I hope they fix it
pretty soon.

Regards,

Stein Vidar