Re: [ferret_users] [Ferret 5.70] define axis

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Jimmy,
The values of the coordinates for any axis must be strictly increasing 
or decreasing. You could use a SORT function on the list of pressure 
values and define the axis from the sorted pressures.  You'll want to 
study the documentation for sorting; it requires a call to both a SORT 
and a SAMPLE function, as in the demo at

  http://www.ferret.noaa.gov/Ferret/Demos/ef_sort_demo/ef_sort_demo.html

Or, you can define a range of pressure values for the new axis, whatever 
they should reasonably be, for example

  def axis/z/units="millibar" zz={100, 200, 250, 600}

Ansley

jimmyc@iastate.edu wrote:

> Hi All-
>
> I am working with sigma coordinate model data. I would like to use 
> pressure as my vertical axis.
> I trid using some information from the email archive to no avail.
> let plevs= pressure[]
> def axis/z zz=plevs
> I get the error that says my axis is not able to be defined because it 
> is not monotonic. Is z restricted to be linear?
>
> I would like to use shade to plot the temperature using the model x 
> coordinate and the new pressure coordinate. Is this possibleor do I 
> need to do some trickery?