`ismissing`

Marks missing values: NaN, NaT, missing strings, undefined categories and empty text.

Category: Language Fundamentals > Data Types

Syntax

tf = ismissing(A)

Returns a logical array that is true where an element is missing.

Description

What counts as missing depends on the type. For floating-point numbers it is NaN; for datetime NaT; for a string array the missing value; for a categorical array an undefined element; and for a cell array of character vectors an empty vector ''.

Integer and logical arrays cannot hold a missing value, so the result is all false. A related function, rmmissing, removes the flagged elements.

Input arguments

A: Numeric array, string array, cell array of character vectors, categorical, datetime or duration array.

Output arguments

tf: Logical array the same size as A.

Example

Different kinds of missing

ismissing([1 NaN 3])
ismissing(["a", missing])
ismissing({'a', ''})
ismissing(categorical({'a', ''}))

Output

ans = 1×3 logical array

   0   1   0
ans = 1×2 logical array

   0   1
ans = 1×2 logical array

   0   1
ans = 1×2 logical array

   0   1

Notes

For tables and for character matrices, MatLivre's ismissing does not flag every entry that MATLAB flags (for example blank characters). Prefer applying it to plain arrays.

ismissing