# Risk neutral conversion of parameters of GAL distirbution # # Author: Francois Pelletier # # LGPL 3.0 ############################################################################### #' Risk neutral conversion of parameters of GAL distirbution #' @param param Parameter vector #' @param riskfree Risk-free rate #' @param type Choose between "mu" or "kappa" parametrization #' @param log Logical for log-parameters #' @return Risk neutral parameter vector #' @export riskneutralparGAL #' @author Francois Pelletier riskneutralparGAL <- function(param,riskfree,type="mu",log=FALSE) { testparGAL(param,type,log) if(type=="kappa") { return(riskneutralparGAL(changetypeGAL(param,type="kappa",target="mu"),riskfree,type="mu",log)) } if(type=="mu") { if(log) { return(c(log(riskfree+log(1-exp(param[3])-exp(param[2])^2/2)*param[4]),param[2],param[3],param[4])) } else { return(c(riskfree+log(1-param[3]-param[2]^2/2)*param[4],param[2],param[3],param[4])) } } }