[ferret_users] interpolate along time axis

[michael hughes <michael.hughes@xxxxxxxxxxxxxxx>]

Hi All

I want to perform a linear interpolation on GCM data along the time axis. The existing data set is organised as separate files representing snapshots at 5 day intervals and I've created a Descriptor file to work with the data within Ferret. I want to interpolate these results from 5 day to 1 day.

From what I can gather this should be a rather trivial task, however I can't seem to get my code to work. When I plot the interpolated results the figure indicates that there is no valid data in the interpolated data set.

!--------------------------

use GCM_data.DES

LET var_5day = temp ! for example

! interpolate data along new time axis

DEFINE AXIS/t=25-JUN-1992:31-DEC-1999:1/UNITS=days tax_1day

LET var_1day = var_5day[Gt=tax_1day@LIN]

!-------------------------

The DES file used to import the data has a time axis at exactly 5 day intervals and I want the new axis to interpolate at 1 day intervals. However the output data set has no valid data. 

Thanks in advance for you help,

Michael Hughes

PhD Candidate

Griffith University

Brisbane, Australia