Eric,

OK, that seems to work. I tried something with scale_units earlier

without success, but I must have been doing something wrong.

Thanks for the help.

Dave

## ···

On 2012/08/29 10:07 AM, David Raymond wrote:

> >

> > I think that I have found a serious bug in vector plotting (quiver)

> > when the "angle=xy" option is used on a plot with a large aspect

> > ratio. It is my understanding that with this option, the vector with

> > tail at (x,y) would have its head at (x + vx,y + vy); at least this is

> > what it says in the documentation.

>

> Not a bug.

> Note this in the documentation:

>

> *scale_units*: *None*, or any of the *units* options.

> For example, if *scale_units* is 'inches', *scale* is 2.0, and

> ``(u,v) = (1,0)``, then the vector will be 0.5 inches long.

> If *scale_units* is 'width', then the vector will be half the width

> of the axes.

>

> If *scale_units* is 'x' then the vector will be 0.5 x-axis

> units. To plot vectors in the x-y plane, with u and v having

> the same units as x and y, use

> "angles='xy', scale_units='xy', scale=1".

>

> Try this modified call to quiver:

>

> q = plt.quiver(X, Y, vx, vy, angles='xy', scale_units='xy')

>

> Eric