! err682_xact_high_prec.jnl
! based on an example from the Users List, 
! http://www.pmel.noaa.gov/maillists/tmap/ferret_users/fu_2012/msg00477.html

! shows that the @XACT regridding in double-precision Ferret is broken.


Let time = {\
 22585.3295833333,\
 22585.3302777778,\
 22585.3309722222,\
 22585.3316666667,\
 22585.3323611111,\
 22585.3330555556,\
 22585.33375,\
 22585.3344444444,\
 22585.3351388889,\
 22585.3358333333}

Define Axis /T /From /T0=1-JAN-1950 /Units=days my_axis = time

Let fake_var = T[GT=my_axis]
Let var = RANDU( fake_var )
Let var_regrid = RESHAPE( var, fake_var )

List /T="2-nov-2011 07:54":"2-nov-2011 08:04" var_regrid

! Note that if we define the axis as below, the regridding is
! successful. But the @XACT regridding in v6.82 was requiring too 
! much matching precision.

!    DEFINE AXIS/t="02-nov-2011:07:54:36":"02-nov-2011:08:03:36":60/units=seconds/T0=1-JAN-1950 my_axis
!    let time = t[gt=my_axis]
!    Let var = TSEQUENCE( RANDU( time ) )
!    Let fake_var = T[GT=my_axis]
!    Let var_regrid = RESHAPE( var, fake_var )

! New time axis
Define Axis /T="01-NOV-2011 00:00":"30-NOV-2011 23:00":1 /Units=seconds /T0=1-JAN-1950 t_axis_seconds

Let var_sec = var_regrid[ GT=t_axis_seconds@XACT ]

! Here we got no good data, should be one at 7:54:36.

List /T="2-nov-2011 07:54:30":"2-nov-2011 07:54:50" var_sec

