07_Tips and Troubleshooting - Geronimorz/Test GitHub Wiki

1. Spherical interpolation itp = interpolate((lons, lats, z), sn[:,:,:],Gridded(Linear())) is valid, as gridded interpolation treats each axis independently

The output is the same as

itp = itp_sph_v_builder(lons, lats, z, sn)

function itp_sph_v_builder(lons, lats, zs, sn)
    function interp_func(lon_inp, lat_inp, z)
    if z <= zs[1]
        z1, z2 = zs[1], zs[1]
        i1, i2 = 1, 1
    elseif z >= zs[end]
        z1, z2 = zs[end], zs[end]
        i1, i2 = length(zs)-1, length(zs)
    else
        i2 = searchsortedfirst(zs, z)
        i1 = i2 - 1
        z1, z2 = zs[i1], zs[i2]
    end

    itp_2D_1 = interpolate((lons, lats), sn[:,:,i1],Gridded(Linear()))
    itp_2D_2 = interpolate((lons, lats), sn[:,:,i2],Gridded(Linear()))
    zeta1 = itp_2D_1(lon_inp, lat_inp)
    zeta2 = itp_2D_2(lon_inp, lat_inp)
    if z1 == z2
        return zeta1
    else
        zeta = zeta1 + (z - z1) * (zeta2 - zeta1) / (z2 - z1)
        return zeta
    end
    end
end