Using interp2 with pcolor and loop.

Hi all.

I have the script created below for mapping wind speeds off the Irish coast. I am trying to use interp2 to use a finer grid but it will not work for me so I must be putting it in the wrong place. Does anyone have any suggestions on how and where in the script interp2 should be integrated?

Thank you.

%%%% SCRIPT %%%%%
long = ncread(ncfile,'longitude'); 
lat = ncread(ncfile,'latitude');

% create a cartesian grid in 2-D space using longitude and latitude
[X,Y] = meshgrid(long,lat);
[X_ERA5,Y_ERA5] = meshgrid(lon_ERA5,lat_ERA5);

for i = 1:72
    for j = 1:88
        lat_pixel = Y(i,j);
        lon_pixel = X(i,j)+360;
        diffLat = abs(lat_ERA5-lat_pixel);
        diffLon = abs(lon_ERA5-lon_pixel);
        lat_index = find(diffLat==min(diffLat));
        lon_index = find(diffLon==min(diffLon));
        WinPwrMap (i,j) = wind_speed (lat_index,lon_index);
    end
end

figure (1)
pcolor(X,Y,WinPwrMap);
shading interp;
sgtitle('Wind Power Resource off Irish Coast')
colorbar
xlabel ('Longitude')
ylabel ('Latitude')
colormap('jet')
c = colorbar;
c.Label.String = 'Wind Speed (m/s)';

[Jan]

"it will not work for me" - please explain any details of the occurring problems. Post the code you have tried, and the corresponding error message.

Answer 1

[SaiDileep Kola]

I see that you have set of coordinates (X,Y) and (X_ERA5,Y_ERA5), you can use interp2 to get 2-D gridded

Vq = interp2(X,Y,V,Xq,Yq)

You may refer to the MATLAB documentation for interp2 and pcolor

interp2: https://www.mathworks.com/help/matlab/ref/interp2.html

pcolor: https://www.mathworks.com/help/matlab/ref/pcolor.html