Remove missing values.
If x is a vector, removes elements with missing values. If x is a matrix, removes rows or columns with missing data elements.
dim is the dimension to operate along. Specifying a dimension forces
to operate in matrix instead of vector mode.
MinNumMissing indicates how many missing element values there must be in a row or column for it to be considered missing and this removed. This option is only used in matrix mode; it is silently ignored in vector mode.
Returns: out - the input, with missing elements or rows or columns removed tf - a logical index vector indicating which elements, rows, or columns were removed