Use is* Functions to Detect State

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
isapprox	Determine approximate equality
isbanded	Determine if matrix is within specific bandwidth
isbetween	Determine which elements are within specified range
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
islocalmax2	Find local maxima in 2-D data
islocalmin	Find local minima in input
islocalmin2	Find local minima in 2-D data
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
istall	Determine 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
isuniform	Determine if vector is uniformly spaced
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