[ncl-talk] masking a 2dfield

[Francesco Trotta]

Dear ncl-team

    I've a file containg the bathymetry (nx * ny) and I would like to mask a subdomain containg inside a closed polyline.


    For a square polyline a try the solution below, but I would like to extend this procedure to a generic closed polyline.

    Is there in ncl a function which allow me to mask a particular region of a 2d-field?





if(lonWest_isletoMask .ge. lon1dt_surf(0) .or. lonEast_isletoMask .le. lon1dt_surf(nx(inest)-1)) then
      if(latSout_isletoMask .ge. lat1dt_surf(0) .or. latNort_isletoMask .le. lat1dt_surf(ny(inest)-1)) then
         idxlon_isletoMask = ind((lon1dt_surf(0:nx-1) .ge. lonWest_isletoMask) .and. (lon1dt_surf(0:nx-1) .le. lonEast_isletoMask))
         idxlat_isletoMask = ind((lat1dt_surf(0:ny-1) .ge. latSout_isletoMask) .and. (lat1dt_surf(0:ny-1) .le. latNort_isletoMask))
         do j=0,dimsizes(idxlat_isletoMask)-1
                  do i=0,dimsizes(idxlon_isletoMask)-1
                     if((.not.ismissing(idxlon_isletoMask(i))) .and. (.not.ismissing(idxlat_isletoMask(j))))
                        bathy(idxlat_isletoMask(j),idxlon_isletoMask(i)) = 0.
                     end if
              end do
          ;print(" ")
           end do
         delete(idxlon_isletoMask)
         delete(idxlat_isletoMask)
      end if
   end if




thanks

Francesco
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