A mask of an array with respect to a given threshold is found by taking the
original array and setting all elements falling below the threshold to
FALSE
and the others to TRUE
. An object of class arr_mask has the
attribute thresh
detailing the threshold value that was applied.
arr_mask(arr, thresh)
An array of logicals (the mask).
The threshold. Either a scalar or an object of class th.
An object of class masked_arr
.