ismissing
              Find missing data in a numeric or string array.
 Given an input numeric data array, char array, or array of cell strings
 A, ismissing returns a logical array TF with
 the same dimensions as A, where true values match missing
 values in the input data.
The optional input indicator is an array of values that represent missing values in the input data. The values which represent missing data by default depend on the data type of A:
NaN: single, double.
 ' ' (white space): char.
 {''}: string cells.
  Note: logical and numeric data types may be used in any combination
 for A and indicator. A and the indicator values will be
 compared as type double, and the output will have the same class as A.
 Data types other than those specified above have no defined ’missing’ value.
 As such, the TF output for those inputs will always be
 false(size(A)). The exception to this is that indicator
 can be specified for logical and numeric inputs to designate values that
 will register as ’missing’.
See also: fillmissing, rmmissing, standardizeMissing
Source Code: ismissing