Display netcdf data over specific country

I have a netcdf file containg data for a region over southern africa. I only want to plot the data over South Africa and not the rest of the region.

Using the borders function and changing the transparency I have almost got the map that I want except that the data is still displayed over the ocean. How can I mask out the ocean region

% Draw nc varibale on map of SA
ncfile = 'OMI-Aura_L3-OMUVBd_2004m1001_v003-2016m0525t164359.he5.nc';
long_uv = ncread(ncfile,'lon');
lat_uv = ncread(ncfile,'lat');
uvi = ncread(ncfile,'UVindex');
% Plot variable
[X,Y] = meshgrid(long_uv,lat_uv);
colormap jet
pcolor(X,Y,uvi');
shading interp
h= colorbar('horiz');
xlabel(h,'UVI');
hold on
% Plot SA map over variable
[lat,lon] = borders('south africa');
pgon = polyshape(lon,lat,'simplify',false);
plot(pgon,'FaceColor','none','FaceAlpha',0)
clear lat lon pgon
hold all
    % Zimbabwe
    [lat,lon] = borders('zimbabwe');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon
    hold all
    % Nambia
    [lat,lon] = borders('Namibia');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon
    hold all
    % Botswana
    [lat,lon] = borders('botswana');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon
    hold all
    % Mozambique
    [lat,lon] = borders('mozambique');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon
    % Lesotho
    [lat,lon] = borders('lesotho');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon
    % Swaziland
    [lat,lon] = borders('swaziland');
    pgon = polyshape(lon,lat,'simplify',false);
    plot(pgon,'FaceColor','white','FaceAlpha',1)
    clear lat lon pgon

[BN]

I have a same problem bro, did you find any solution BTW?

[David du Preez]

Yes. Get the latitudes and longtiudes of the countries using the borders function and then look at this answer https://ch.mathworks.com/matlabcentral/answers/486421-change-color-outside-region-of-polyshape