robust GP kernel input-metric example
gp_empirical_input_covariance_rmse=0.3566
gp_robust_input_covariance_rmse=0.1813
empirical_covariance_diag= [0.6417 1.8476]
robust_covariance_diag=    [0.5296 0.0273]
saved diagnostics to results/use_cases/gp_robust_input_metric
