! jnl file that uses Argo data to make geostrophic velocity section overlay plots

!let section_direction=`$1%N%`

! begin mapping process

! don't want to plot geostrophic velocity within 5 degrees of equator 
let msk=if y[g=`temp,return=grid`] lt 5 and y[g=`temp,return=grid`] gt (-5) then 0 else 1
let vx=geo_uz*msk
let vel_x=if vx ne 0 then vx
let vz=geo_vz*msk
let vel_z=if vz ne 0 then vz

! geostrophic velocity can only be plotted if the depths are different. 
! depth is the same
let a=if `depth_min` eq `depth_max` then 1 else 0
if `a` then say "depth is the same - cannot graph velocity"

let b=if `time_start` eq `time_end` then 1 else 0 
let c=if (`xlo`) ne (`xhi`) then 1 else 0
let d=if (`ylo`) ne (`yhi`) then 1 else 0
let e=if `time_start` ne `time_end` then 1 else 0
let boundb=if (`xlo`) gt (`xhi`) then 1 else 0

! now can start plotting velocity vectors over

if `b` then 
if ($1%TRUE|N>TRUE|E>FALSE|>TRUE%) then 	!checking whether it is a N-S or E-W section & assigning N-S as default
if `c` then

! plotting
vector/nolab/over/pen=black vel_x[y=`ylo`:`yhi`,x=`xlo`:`xhi`@ave,l=`time_start`,z=`depth_min`:`depth_max`],vel_z[y=`ylo`:`yhi`,x=`xlo`:`xhi`@ave,l=`time_start`,z=`depth_min`:`depth_max`]  

else ! no averaging over x

! plotting
vector/nolab/over/pen=black vel_x[y=`ylo`:`yhi`,x=`xlo`,l=`time_start`,z=`depth_min`:`depth_max`],vel_z[y=`ylo`:`yhi`,x=`xlo`,l=`time_start`,z=`depth_min`:`depth_max`]  
endif	! c loop

else ! E-W section

! Ensuring longitudes are properly plotted



if `boundb` then
let xhi=`xhi`+360
endif 


if `d` then 

! plotting
vector/nolab/over/pen=black vel_x[x=`xlo`:`xhi`,y=`ylo`:`yhi`@ave,l=`time_start`,z=`depth_min`:`depth_max`],vel_z[x=`xlo`:`xhi`,y=`ylo`:`yhi`@ave,l=`time_start`,z=`depth_min`:`depth_max`] 

else ! no averaging over y

! plotting
vector/nolab/over/pen=black vel_x[x=`xlo`:`xhi`,y=`ylo`,l=`time_start`,z=`depth_min`:`depth_max`],vel_z[x=`xlo`:`xhi`,y=`ylo`,l=`time_start`,z=`depth_min`:`depth_max`] 

endif	! d loop

endif	!b
endif !n-s

! time is different

 
if `e` then 
if ($1%TRUE|N>TRUE|E>FALSE|>TRUE%) then 	!checking whether it is a N-S or E-W section & assigning N-S as default

if `c` then

! plotting
vector/nolab/over/pen=black vel_x[y=`ylo`:`yhi`,x=`xlo`:`xhi`@ave,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`],vel_z[y=`ylo`:`yhi`,x=`xlo`:`xhi`@ave,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`]  

else ! no averaging over x

! plotting
vector/nolab/over/pen=black vel_x[y=`ylo`:`yhi`,x=`xlo`,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`],vel_z[y=`ylo`:`yhi`,x=`xlo`,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`]  
endif	! c loop

else ! E-W section

if `d` then 

! plotting
vector/nolab/over/pen=black vel_x[x=`xlo`:`xhi`,y=`ylo`:`yhi`@ave,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`],vel_z[x=`xlo`:`xhi`,y=`ylo`:`yhi`@ave,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`] 

else ! no averaging over y

! plotting
vector/nolab/over/pen=black vel_x[x=`xlo`:`xhi`,y=`ylo`,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`],vel_z[x=`xlo`:`xhi`,y=`ylo`,l=`time_start`:`time_end`@ave,z=`depth_min`:`depth_max`] 

endif	! d loop

endif	!e
endif !n-s