Prepends (appends) the scalar value c to the vector x until it is of length l. If the third argument is not supplied, a value of 0 is used.
If
length (
x) >
l, elements from the beginning (end) of x are removed until a vector of length l is obtained.If x is a matrix, elements are prepended or removed from each row.
If the optional dim argument is given, then operate along this dimension.