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 LAP vertical coordinate formul ... ... 1:95 ...B vertical coordinate formul ... ... 1:95 ...PS Surface Air Pressure 1:192 1:96 ... 1:120AP_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 1:120let 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 ambiguousdefine axis/from_data/z/unit="Pa" pressure_axis=P[k=1:95]Command file, command group, or REPEAT execution abortedAm I doing it right way? Or is it not possible to define axis this way?Regards,Vivek