# R code developed by:
# International Research Institute for Climate and Society
# Columbia University in the City of New York, USA
# Last update: Jully 3, 2013
# --------------------------------------------------------------------------------
# Dependancies : (see each function for further details)
#		NONE
# --------------------------------------------------------------------------------
# Results :
#		-- A n * length(param_base) matrix of random parameters
# --------------------------------------------------------------------------------
# Parameters :
#		-- n the number of sets of parameters to generate
#		-- param_min the vector of the minimum values of the parameters
#		-- param_max the vector of the maximum values of the parameters
#		-- Dist a key word to choose the type of distribution wanter for the random generation. Can be "Unif" (uniform distribution), "Norm95" (normal distribution with 95% chances of being in the right interval) or "Norm99" (normal distribution with 99% chances of being in the right interval)
# --------------------------------------------------------------------------------
# Actions :
#		-- Select the key word
#		-- For each parameter, generate a random vector of size n following the specifications
#		-- Bind all the vectors together
#		-- Return the matrix X
# --------------------------------------------------------------------------------

Random_Param <- function (n, param_min, param_max, Dist){
	
	X <- NULL
	if (Dist=="Unif") {
		for (i in 1:length(param_min)) {
			mini <- param_min[i]
			maxi <- param_max[i]
			X <- cbind(X,matrix(runif(n,mini,maxi),nrow=n))
		}
	}else if (Dist=="Norm95"){
		for (i in 1:length(param_min)) {
			mini <- param_min[i]
			maxi <- param_max[i]
			moy<-(mini+maxi)/2
			err<-(maxi-mini)/(2*2)
			All<-rnorm(n,moy,err);
			All[All<mini]<-mini; # Put out-ranged values to minimum bound
			All[All>maxi]<-maxi; # Put out-ranged values to maximum bound
			X <- cbind(X,matrix(All,nrow=n))
		}	
	}else if (Dist=="Norm99"){
		for (i in 1:length(param_min)) {
			mini <- param_min[i]
			maxi <- param_max[i]
			moy<-(mini+maxi)/2
			err<-(maxi-mini)/(2*3)
			All<-rnorm(n,moy,err);
			All[All<mini]<-mini; # Put out-ranged values to minimum bound
			All[All>maxi]<-maxi; # Put out-ranged values to maximum bound
			X <- cbind(X,matrix(All,nrow=n))
		}
	}
	return(X)
}