#' Check if a variable is declared.
#'
#' @param object Variable name to check
#' @param key Optional key to check inside object.
#'
#' @return TRUE or FALSE indicating if the variable is initialized & non-empty.
#'
is.declared <- function(object, key = NULL) {
if (! is.null(key)) {
if (! isS4(object)) {
if (! exists(key, where = object))
return(FALSE)
object <- get(key, object)
} else {
object <- slot(object, key)
}
}
# Check length, is.null, etc
check <- ! is.null(object)
# Check empty matrix
if (check) {
if (! is.null(dim(object))) {
check <- ! all(is.na(object))
} else {
check <- as.logical(length(object))
}
}
return(check)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.