TransfoParam_CemaNeige.R

TransfoParam_CemaNeige <- function(ParamIn, Direction) {
  
  NParam <- 2
  Bool <- is.matrix(ParamIn)
  
  if (Bool == FALSE) {
    ParamIn <- rbind(ParamIn)
  }
  
  if (ncol(ParamIn) != NParam) {
    stop(paste( "the CemaNeige module requires ", NParam, " parameters \n", sep = "" ))
    return(NULL)
  }
  
  if (Direction == "TR") {
    ParamOut <-  ParamIn
    ParamOut[, 1] <- (ParamIn[, 1] + 9.99) / 19.98 ### CemaNeige X1 (weighting coefficient for snow pack thermal state)
    ParamOut[, 2] <- exp(ParamIn[, 2]) / 200       ### CemaNeige X2 (degree-day melt coefficient)
  }
  
  if (Direction == "RT") {
    ParamOut <-  ParamIn
    ParamOut[, 1] <-  ParamIn[, 1] * 19.98 - 9.99  ### CemaNeige X1 (weighting coefficient for snow pack thermal state)
    ParamOut[, 2] <- log(ParamIn[, 2] * 200)       ### CemaNeige X2 (degree-day melt coefficient)
  }
  
  if (Bool == FALSE) {
    ParamOut <- ParamOut[1, ]
  }
  
  return(ParamOut)
  
}