[ferret_users] Define axis/from_data

[vivek shilimkar <vivek.shilimkar@xxxxxxxxx>]

Dear all,

I have been trying to define new vertical axis for my data.

However, I am getting following error in ferret.

currently SET data sets:

    1> ./cl.nc  (default)

 name     title                                          I            J         K         L

 AP       vertical coordinate formul         ...          ...       1:95      ... 

 B        vertical coordinate formul          ...           ...       1:95      ...

 PS       Surface Air Pressure              1:192     1:96      ...       1:120

 AP_BNDS  vertical coordinate formul  1:2       ...         1:95      ...

 B_BNDS   vertical coordinate formul    1:2       ...         1:95      ...

 CL       Cloud Area Fraction                 1:192     1:96    1:95      1:120

let P = ap+(b*ps)

define axis/from_data/z/unit="Pa" pressure_axis=P[k=1:95]

           *** NOTE: (fyi) units are not subject to auto-conversion: PA

**ERROR: improper grid or axis definition: data for DEFINE AXIS/FROM_VARIABLE is ambiguous

define axis/from_data/z/unit="Pa" pressure_axis=P[k=1:95]

Command file, command group, or REPEAT execution aborted

Am I doing it right way? Or is it not possible to define axis this way?

Regards,

Vivek