function [rmse, corr, bias] = calc_rmse_r (lh_stn, lh_wrf, ropt_number)


    lh_wrf_mean = squeeze(nanmean(lh_wrf,2));

    stn    = nanmean(lh_stn,2);
    runopt = lh_wrf_mean(ropt_number,:)';
    
    stn_valid    = stn(~isnan(stn));
    runopt_valid = runopt(~isnan(stn));
    
    rmse = sqrt(mean((runopt_valid - stn_valid).^2));
    
    corr_temp = corrcoef(stn_valid, runopt_valid);
    corr = corr_temp(1,2);

    bias = nanmean(runopt_valid - stn_valid);
    
end 
