return the maximum CCF value along with corresponding lag value

fun_ccfmax.R

## Original arthur: vikrant @ R help mailing list
## return the maximum CCF value along with corresponding lag value
## http://r.789695.n4.nabble.com/ccf-function-td2288257.html

fun.ccfmax <- function(a,b) { 
 d <- ccf(a, b, plot = FALSE) 
 cor = d$acf[,,1] 
 lag = d$lag[,,1] 
 res = data.frame(cor,lag) 
 res_max = res[which.max(res$cor),] 
 return(res_max) 
}