R/span.R

In frousseu/rNest: Estimating Nesting Chronology and Breeding Phenology in Birds

span <-
function(x,y){
           if(length(x)==0){return(0)}
           stopifnot(inherits(x,"Date"))
           if(missing(y)){
                r<-range(x,na.rm=TRUE)
           }else{     
                stopifnot(inherits(y,"Date"))
                r<-range(c(x,y),na.rm=TRUE)
                }
           ans<-abs(as.numeric(difftime(r[1],r[2])))+1     
           ans
           }