[ncl-talk] lat-lon to ij for NARR

[Mary Haley]

Ashish,

>From your script, I'm not sure how you are determining the values are
wrong, as I didn't see that you were actually printing any lat/lon values.

Did you try doing any debugging of your code to see where the problem was?

It first helps to verify that the min/max lat/lon values you are inputting
to getind_latlon2d are close in the range of your 2D lat/lon arrays.

A simple "printMinMax" will give you that information:

printMinMax(lat2d_narr,0)
printMinMax(lon2d_narr,0)

If this looks good then print "nm" to make sure these values look okay:

print("lat2d_narr dims = " + dimsizes(lat2d_narr))
print("nm = " + nm)    ; To make sure nm values are not out-of-range of
your 2D lat/lon array

If the above looks okay then try:

  iStrt    = nm(0,0)
  jStrt    = nm(0,1)
  iLast    = nm(1,0)
  jLast    = nm(1,1)
  lat_strt = lat2d_narr(iStrt,jStrt)
  lat_last = lat2d_narr(iLast,jLast)
  lon_strt = lon2d_narr(iStrt,jStrt)
  lon_last = lon2d_narr(iLast,jLast)
  print("lat/lon start = " + lat_strt + "/" + lon_strt)
  print("lat/lon last  = " + lat_last + "/" + lon_last)

Hopefully the above code will help you locate the source of the error.

--Mary


On Wed, Mar 16, 2016 at 1:12 PM, Ashish Sharma <asharma7 at nd.edu> wrote:

> Hello,
>
> I am trying to find corresponding ij for lat-lon pair from NARR data using
> *getind_latlon2d* command, but the values are wrong.
>
> Please advise.
>
> thanks,
> Ashish
>
>   minlat =  37.37814
>
>   maxlat =  46.64286
>
>   minlon = -98.91251
>
>   maxlon = -73.89026
>
>
> ;=================================================;
>
> f3 = addfile("land.nc","r")
>
>   lat2d_narr  = f3->lat                ; (277,349)
>
>   lon2d_narr  = f3->lon
>
>
>   printMinMax(lat2d_narr, 0)
>
>   printMinMax(lon2d_narr, 0)
>
>
>  lat   = (/ minlat,maxlat  /)   ; user specified coordinate pairs
>
>  lon   = (/minlon,maxlon /)
>
>
>   nm = *getind_latlon2d* (lat2d_narr,lon2d_narr, lat, lon)
>
>  print(nm)
>
>   iStrt = nm(0,0)
>
>   jStrt = nm(0,1)
>
>   iLast = nm(1,0)
>
>   jLast = nm(1,1)
>
>
>
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