R/ndvi.R

In rmmarcos/pruebapaquete:

#' Calculate NDVI
#'
#' This function caculates the normalized difference vegetation index.
#'
#' @param b1 value or vector with reflectance in the first (eg. NIR for NDVI) wavelenght
#' @param b2 value or vector with reflectance in the second (eg. red for NDVI) wavelenght
#' @return NDVI value
#' @export
#'

ndiff <- function(b1,b2){
  return((b1-b2)/(b1+b2))
}

##################
#' Calculate nSAVI
#'
#' This function caculates the normalized difference vegetation index.
#'
#' @param b1 value or vector with reflectance in the first (eg. NIR for NDVI) wavelenght
#' @param b2 value or vector with reflectance in the second (eg. red for NDVI) wavelenght
#' @param L soil coefficient. Set to 0.5 by default
#' @return NDVI value
#' @export
#'

nsavi <- function(b1,b2,L=0.5){
  return(((b1-b2)/(b1+b2+L))*(1+L))
}