gpr_ex1  First exmaple of Gaussian Process, using only one covariate. (linear + pow.ex)
gpr_ex2	 	  Second exmaple of Gaussian Process, using two covariate with larger sample size. (linear + pow.ex)
co2 	  Real data example of Gaussian Process, three different covariance structure, including one customized covariance matrix. 
gpfr		  Gaussian Process with functional mean. 
