#' build_ndvi_desc
#'
#' @param folder tbc
#' @param date.loc tbc
#' @param date.format tbc
#' @param start.date tbc
#' @param end.date tbc
#'
#' @return
#' @export
#'
#' @examples
build_ndvi_desc <- function(folder, # full path location of folder containing NDVI geotifs
date.loc=c(15,21), # character location in filenames of NDVI containing dates
date.format="%Y%j", # format of dates
start.date = NULL,
end.date = NULL){
ndvi.data <- data.frame(filenames=list.files(folder,pattern = "MOD13Q1"),
year=NA,
date=lubridate::ymd("1970-01-01"))
ndvi.data$filenames <- as.character(ndvi.data$filenames)
ndvi.data$date <- as.Date(substr(ndvi.data$filenames, date.loc[1], date.loc[2]),
format=date.format,
tz="GMT")
ndvi.data$year <- lubridate::year(ndvi.data$date)
ndvi.data$folder <- folder
## order by date
ndvi.data <- ndvi.data[order(ndvi.data$date),]
ndvi.data[,1] <- as.character(ndvi.data[,1])
## filter by start and end date if provided
if (!is.null(start.date)){
start.date <- as.Date(start.date)
ndvi.data <- ndvi.data[ndvi.data$date >= start.date,]
}
if (!is.null(end.date)){
end.date <- as.Date(end.date)
ndvi.data <- ndvi.data[ndvi.data$date <= end.date,]
}
return(ndvi.data)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.