# R/omega_root.R In ecor/RMRAINGEN: RMRAINGEN (R Multi-site RAINfall GENeretor): a package to generate daily time series of rainfall from monthly mean values

#### Documented in omega_root

```NULL
#'
#' This is the target function whose zero is searched to crete the inverse function of  \code{\link{omega}}.
#'
#' @param x value of expected correlation between the corresponding Gaussian-distributed variables
#' @param p0_v1,p0_v2 probablity of no precipitatin occurences for the v1 and v2 time series respectively.
#' @param p00 probability of no precipitation occurence in both v1 and v2 simultanously returned by \code{\link{omega}}
#' @param correlation numerical value. DEfault is \code{NA}.  Binary correlation retured by \code{\link{omega}}  when the argumet \code{correlation=TRUE}
#'
#' @author Emanuele Cordano
#'
#' @return  the value \code{p00-omega(x=x,p0_v1=p0_v1,p0_v2=p0_v2)} or \code{correlation-omega(x=x,p0_v1=p0_v1,p0_v2=p0_v2)} (if \code{correlation} is not \code{NA})
#'
#' @note This function makes use of normal copula
#'
#' @export
#' @examples

#' rho <- 0.4
#' p00 <- omega(x=rho,p0_v1=0.5,p0_v2=0.5)
#' omega_root(x=rho,p0_v1=0.5,p0_v2=0.5,p00=p00)

# TO GO ON with omega ....

omega_root <- function(x=0.5,p0_v1=0.5,p0_v2=0.5,p00=p0_v1*p0_v2,correlation=NA) {

if (is.na(correlation)) {
out <- p00-omega(x,p0_v1=p0_v1,p0_v2=p0_v2,correlation=FALSE)
} else {
out <- 	correlation-omega(x,p0_v1=p0_v1,p0_v2=p0_v2,correlation=TRUE)
}
return(out)
}
```
ecor/RMRAINGEN documentation built on May 13, 2017, 1:02 p.m.