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Detect States of Variables Using is* Functions

MATLAB® has many functions that detect if an array or object has a specified state. These functions are sometimes referred to as the is* functions because their names start with is. The functions return logical 1 (true) if the inputs have the specified states, and logical 0 (false) otherwise.

For example, you can use these functions to detect if:

  • An array has a specified data type (such as numeric, double, categorical, datetime, or string)

  • A numeric matrix has certain properties (such as being symmetric)

  • The elements of a numeric array are finite, real, or complex

  • The elements of a categorical or datetime array meet certain conditions

  • An array has any elements that are outliers, missing values, or local maxima or minima

  • An object is a graphics handle, or a Java® or COM object

This table contains an alphabetical list of the most notable is* functions with descriptions of the states that they detect.

Function

Description

isa

Determine if input has specified data type

isappdata

Determine if application data exists

isbanded

Determine if matrix is within specific bandwidth

isbetween

Find elements of datetime or duration array that are within date and time interval

iscalendarduration

Determine if input is calendarDuration array

iscategorical

Determine if input is categorical array

iscategory

Determine if inputs are names of categories

iscell

Determine if input is cell array

iscellstr

Determine if input is cell array of character vectors

ischange

Find abrupt changes in input

ischar

Determine if input is character array

iscolumn

Determine if input is column vector

iscom

Determine if input is Component Object Model (COM) object

isConfigured

Determine if dictionary is configured

isdatetime

Determine if input is datetime array

isdiag

Determine if matrix is diagonal

isdst

Find elements of datetime array that occur during daylight saving time

isduration

Determine if input is duration array

isempty

Determine if input is empty array

isenum

Determine if input is enumeration

isequal

Determine if arrays are numerically equal

isequaln

Determine if arrays are numerically equal, treating NaNs as equal

isevent

Determine if input is Component Object Model (COM) object event

isfield

Determine if input is MATLAB structure array field

isfile

Determine if input is a file

isfinite

Find array elements that are finite

isfloat

Determine if input is floating-point array

isfolder

Determine if input is folder

isgraphics

Determine if input is valid graphics object handle

ishandle

Determine if input is valid graphics or Java object handle

ishermitian

Determine if matrix is Hermitian or skew-Hermitian

ishold

Determine if graphics hold state is on

isinf

Find array elements that are infinite

isinteger

Determine if input is integer array

isinterface

Determine if input is Component Object Model (COM) interface

isjava

Determine if input is Java object

isKey

Determine if dictionary contains key

iskeyword

Determine if input is MATLAB keyword

isletter

Find characters that are letters

islocalmax

Find local maxima in input

islocalmin

Find local minima in input

islogical

Determine if input is logical array

ismac

Determine if version is for macOS platform

ismatrix

Determine if input is matrix

ismember

Find array elements that are members of set array

ismembertol

Find array elements, within tolerance, that are members of set array

ismethod

Determine if object has specified method

ismissing

Find missing values in input

isnan

Find numeric array elements that are NaN (Not-a-Number)

isnat

Find datetime array elements that are NaT (Not-a-Time)

isnumeric

Determine if input is numeric array

isobject

Determine if input is MATLAB object

isordinal

Determine if input is ordinal categorical array

isoutlier

Find outliers in input

ispc

Determine if version is for Windows® (PC) platform

isprime

Find array elements that are prime

isprop

Determine if input is object property

isprotected

Determine if categories of categorical array are protected

isreal

Determine if all numeric array elements are real numbers

isregular

Determine if input times are regular with respect to time or calendar unit

isrow

Determine if input is row vector

isscalar

Determine if input is scalar

issorted

Determine if array is sorted

issortedrows

Determine if matrix or table rows are sorted

isspace

Find characters that are space characters

issparse

Determine if input is sparse

isstring

Determine if input is string array

isStringScalar

Determine if input is string array with one element

isstrprop

Find characters in input strings that are of specified category

isstruct

Determine if input is structure array

isstudent

Determine if version is Student Version

issymmetric

Determine if matrix is symmetric or skew-symmetric

istable

Determine if input is table

istabular

Determine if input is table or timetable

istallDetermine if input is tall array

istimetable

Determine if input is timetable

istril

Determine if matrix is lower triangular

istriu

Determine if matrix is upper triangular

isundefined

Find undefined elements in categorical array

isUnderlyingType

Determine if input has specified underlying data type

isunix

Determine if version is for Linux® or macOS platforms

isvalid

Determine if input is valid handle

isvarname

Determine if input is valid variable name

isvector

Determine if input is vector

isweekend

Find elements of datetime array that occur during weekends

See Also

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