! err700_samplexy_subspan_modulo.jnl
! 7/29/2016 ACM
! Ticket 2458. The result of SAMPLEXY wrong when it needs
! to do a modulo operation on a subspan modulo axis

! Define a grid with a subspan longitude axis

define axis/x=-100:-60:5/units=degrees_east xaxis
define axis/y=18:30:2/units=degrees_north yaxis
let var = x[gx=xaxis]+100 + 0.3*y[gy=yaxis]

save/clobber/file=a.nc var
can var/all; use a

list/y=22 var
list samplexy(var, {-80,80}, {22,22}) 

list samplexy(var, -80, 22)       ! this is ok, in the native range of the axis
list samplexy(var, `360-80`, 22)  ! this was wrong
list samplexy_closest(var, `360-80`, 22)  ! is ok

! Looking for a point that is not, even in a modulo sense, in the subpsan axis

list samplexy(var, {-80,80}, {22,22})
list samplexy(var, {`360-80`,80}, {22,22})
list samplexy_closest(var, {`360-80`,80}, {22,22})

! interpolation between grid points

cancel mode interpolate
list/y=21.2/x=277.7 var
set mode interpolate; list/y=21.2/x=277.7 var; cancel mode interpolate

! These should match the MODE INTERPOLATE result (the second was wrong).

list samplexy(var, {-82.3,82.3}, {21.2,21.2})
list samplexy(var, {`360-82.3`,82.3}, {21.2,21.2})

! this should match the non-MODE INTERPOLATE result
list samplexy_closest(var, {`360-82.3`,82.3}, {21.2,21.2})

can dat/all

! Test samplexyt functions

define axis/t=1:5:1 tax
let vart = x[gx=xaxis]+100 + 0.3*y[gy=yaxis] + 0*t[gt=tax]
save/clobber/file=a.nc vart
can var/all; use a

list vart[x=-80,y=21,t=2]
list samplexyt(vart, {-82.3,82.3}, {21.2,21.2}, {2,2})
list samplexyt(vart, {`360-82.3`,82.3}, {21.2,21.2}, {2,2})
list samplexyt_nrst(vart, {`360-82.3`,82.3}, {21.2,21.2}, {2,2})

! Full-span modulo grid is ok

use coads_climatology
list/l=1/x=-80/y=22 sst
list samplexy(sst[l=1], -80, 22)
list samplexy(sst[l=1], `360-80`, 22)
list samplexy_closest(sst[l=1], `360-80`, 22)

list samplexyt(sst, -80, 22, `t[gt=sst,l=1]`)
