Sort array elements
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Syntax
B = sort(A)
B = sort(A,dim)
B = sort(___,direction)
B = sort(___,Name,Value)
[B,I] =sort(___)
Description
B = sort(A) sorts the elements of A. By default, sort uses ascending sorted order.
If
Ais a vector, thensort(A)sortsthe vector elements.If
Ais a matrix, thensort(A)treatsthe columns ofAas vectors and sorts each column.If
Ais a multidimensional array,thensort(A)operates along the first array dimensionwhose size does not equal 1, treating the elements as vectors.
example
B = sort(A,dim) returnsthe sorted elements of A along dimension dim.For example, if A is a matrix, then sort(A,2) sortsthe elements of each row.
example
B = sort(___,direction) returnssorted elements of A in the order specified by direction usingany of the previous syntaxes. 'ascend' indicatesascending order (the default) and 'descend' indicatesdescending order.
example
B = sort(___,Name,Value) specifiesadditional parameters for sorting. For example, sort(A,'ComparisonMethod','abs') sortsthe elements of A by magnitude.
example
[B,I] =sort(___) also returns a collection of indexvectors for any of the previous syntaxes. I isthe same size as A and describes the arrangementof the elements of A into B alongthe sorted dimension. For example, if A is a vector,then B = A(I).
example
Examples
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Sort Vector in Ascending Order
Open Live Script
Create a row vector and sort its elements in ascending order.
A = [9 0 -7 5 3 8 -10 4 2];B = sort(A)
B = 1×9 -10 -7 0 2 3 4 5 8 9Sort Matrix Rows in Ascending Order
Open Live Script
Create a matrix and sort each of its rows in ascending order.
A = [3 6 5; 7 -2 4; 1 0 -9]
A = 3×3 3 6 5 7 -2 4 1 0 -9B = sort(A,2)
B = 3×3 3 5 6 -2 4 7 -9 0 1Sort Matrix Columns in Descending Order
Open Live Script
Create a matrix and sort its columns in descending order.
A = [10 -12 4 8; 6 -9 8 0; 2 3 11 -2; 1 1 9 3]
A = 4×4 10 -12 4 8 6 -9 8 0 2 3 11 -2 1 1 9 3B = sort(A,'descend')B = 4×4 10 3 11 8 6 1 9 3 2 -9 8 0 1 -12 4 -2Sort String Array
Open Live Script
Starting in R2017a, you can create string arrays using double quotes, and sort them using the sort function. Sort strings in each column of a string array according to Unicode® dictionary order.
A = ["Santos","Burns"; ... "Jones","Morita"; ... "Petrov","Adams"];B = sort(A)
B = 3x2 string "Jones" "Adams" "Petrov" "Burns" "Santos" "Morita"Sort the strings in each row.
B = sort(A,2)
B = 3x2 string "Burns" "Santos" "Jones" "Morita" "Adams" "Petrov"Sort and Index datetime Array
Open Live Script
Create an array of datetime values and sort them in ascending order, that is, from the earliest to the latest calendar date.
ds = {'2012-12-22';'2063-04-05';'1992-01-12'};A = datetime(ds,'Format','yyyy-MM-dd')A = 3x1 datetime 2012-12-22 2063-04-05 1992-01-12[B,I] = sort(A)
B = 3x1 datetime 1992-01-12 2012-12-22 2063-04-05I = 3×1 3 1 2B lists the sorted dates and I contains the corresponding indices of A.
Access the sorted elements from the original array directly by using the index array I.
A(I)
ans = 3x1 datetime 1992-01-12 2012-12-22 2063-04-05Sort Vectors in Same Order
Open Live Script
Create two row vectors that contain related data in the corresponding elements.
X = [3 6 4 2 1 5];Y = ["yellow" "purple" "green" "orange" "red" "blue"];
First sort the vector X, then sort the vector Y in the same order as X.
[Xsorted,I] = sort(X)
Xsorted = 1×6 1 2 3 4 5 6I = 1×6 5 4 1 3 6 2Ysorted = Y(I)
Ysorted = 1x6 string "red" "orange" "yellow" "green" "blue" "purple"Sort 3-D Array
Open Live Script
Create a 2-by-2-by-2 array and sort its elements in ascending order along the third dimension.
A(:,:,1) = [2 3; 1 6];A(:,:,2) = [-1 9; 0 12];A
A = A(:,:,1) = 2 3 1 6A(:,:,2) = -1 9 0 12
B = sort(A,3)
B = B(:,:,1) = -1 3 0 6B(:,:,2) = 2 9 1 12
Use A(:), the column representation of A, to sort all of the elements of A.
B = sort(A(:))
B = 8×1 -1 0 1 2 3 6 9 12Complex Vector
Open Live Script
Sort the elements of a complex vector by their real parts. By default, the sort function sorts complex values by their magnitude, and breaks ties using phase angles. Specify the value of 'ComparisonMethod' as 'real' to instead sort complex values by their real parts. For elements with equal real parts, sort breaks the tie based on their imaginary parts.
A = [1+2i 3+1i 1i 0 -1i];B = sort(A,'ComparisonMethod','real')
B = 1×5 complex 0.0000 - 1.0000i 0.0000 + 0.0000i 0.0000 + 1.0000i 1.0000 + 2.0000i 3.0000 + 1.0000iInput Arguments
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A — Input array
vector | matrix | multidimensional array
Input array, specified as a vector, matrix, or multidimensional array.
If
Ais a scalar, thensort(A)returnsA.If
Ais complex, then by default,sortsortsthe elements by magnitude. If more than one element has equal magnitude,then the elements are sorted by phase angle on the interval (−π,π].If
Ais a cell array of charactervectors or a string array, thensort(A)sorts theelements according to the code order for the UTF-16 character encodingscheme. The sort is case-sensitive. For more information on sortingcharacter and string arrays, see Sort Order for Character and String Arrays.If
Ais a string array, thensortreordersthe elements of the array, but does not reorder characters withinthe strings.If
Ais a categorical array, then the sorting order is based on the category order returned bycategories(A).
Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | cell | categorical | datetime | duration
Complex Number Support: Yes
dim — Dimension to operate along
positive integer scalar
Dimension to operate along, specified as a positive integerscalar. If no value is specified, then the default is the first arraydimension whose size does not equal 1.
Consider a matrix
A.sort(A,1)sortsthe elements in the columns ofA.
sort(A,2)sorts the elements inthe rows ofA.
sort returns A if dim isgreater than ndims(A). dim isnot supported when A is a cell array, that is, sort onlyoperates along the first array dimension whose size does not equal1.
Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64
direction — Sorting direction
'ascend' (default) | 'descend'
Sorting direction, specified as 'ascend' or 'descend'. direction isnot supported when A is a cell array, that is, sort onlysorts in ascending order.
Name-Value Arguments
Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.
Before R2021a, use commas to separate each name and value, and enclose Name in quotes.
Example: sort(A,'MissingPlacement','last')
MissingPlacement — Placement of missing values
'auto' (default) | 'first' | 'last'
Placement of missing values (NaN, NaT, <undefined>,and missing) specified as the comma-separated pairconsisting of 'MissingPlacement' and one of thefollowing:
'auto'— Missing elementsare placed last for ascending order and first for descending order.'first'— Missing elementsare placed first.'last'— Missing elementsare placed last.
ComparisonMethod — Element comparison method
'auto' (default) | 'real' | 'abs'
Element comparison method for numeric input, specified as the comma-separated pair consisting of 'ComparisonMethod' and one of the following:
'auto'— SortAbyreal(A)whenAis real, and sort byabs(A)whenAis complex.'real'— SortAbyreal(A)whenAis real or complex. IfAhas elements with equal real parts, then useimag(A)to break ties.'abs'— SortAbyabs(A)whenAis real or complex. IfAhas elements with equal magnitude, then useangle(A)in the interval (-π,π] to break ties.
Output Arguments
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B — Sorted array
vector | matrix | multidimensional array
Sorted array, returned as a vector, matrix, or multidimensional array. B is the same size and type as A.
Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | cell | categorical | datetime | duration
I — Sort index
vector | matrix | multidimensional array
Sort index, returned as a vector, matrix, or multidimensionalarray. I is the same size as A.The index vectors are oriented along the same dimension that sort operateson. For example, if A is a 2-by-3 matrix, then [B,I]= sort(A,2) sorts the elements in each row of A.The output I is a collection of 1-by-3 row indexvectors describing the rearrangement of each row of A.
The sort function uses a stable sorting algorithm. So, when the input contains repeated values, the sort index preserves the original order from the input, regardless of sorting direction. For example, if A = [1 2 1 2], then [Ba,Ia] = sort(A,'ascend') returns the sort index Ia = [1 3 2 4] and [Bd,Id] = sort(A,'descend') returns the sort index Id = [2 4 1 3].
More About
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Sort Order for Character and String Arrays
MATLAB® stores characters as Unicode® usingthe UTF-16 character encoding scheme. Character and string arraysare sorted according to the UTF-16 code point order. For the charactersthat are also the ASCII characters, this order means that uppercaseletters come before lowercase letters. Digits and some punctuationalso come before letters.
Tips
The
sortrowsfunction providesadditional flexibility for subsorting over multiple columns of matrixor table inputs.The
sortfunction and the relationaloperators use different orderings for complex numbers. For more information,see Relational Operations.
Extended Capabilities
Tall Arrays
Calculate with arrays that have more rows than fit in memory.
This function supports tall arrays with the limitations:
You must specify the dimension to sort, as in
sort(X,dim).Sorting the tall dimension, as in
sort(X,1),is only supported for column vectors.
For more information, see Tall Arrays.
C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.
Usage notes and limitations:
If
Ais complex with all zero imaginary parts, then MATLAB might convertAtoreal(A)before callingsort(A). In this case, MATLAB sortsAbyreal(A), but the generated code sortsAbyabs(A). To make the generated code match MATLAB, usesort(real(A))orsort(A,'ComparisonMethod','real'). See Code Generation for Complex Data with Zero-Valued Imaginary Parts (MATLAB Coder).If you supply
dim, then it must be constant.Variable-sizing support must be enabled when input cell array is heterogeneous.
For limitations related to variable-size inputs, see Variable-Sizing Restrictions for Code Generation of Toolbox Functions (MATLAB Coder).
GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.
Refer to the usage notes and limitations in the C/C++ Code Generation section. The same limitations apply to GPU code generation.
Thread-Based Environment
Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.
This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.
GPU Arrays
Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.
The sort function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).
Distributed Arrays
Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.
Usage notes and limitations:
Table, timetable, and datetime inputs are not supported.
For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).
Version History
Introduced before R2006a
See Also
issorted | max | min | sortrows | unique | topkrows
Topics
- Reshaping and Rearranging Arrays
MATLAB 명령
다음 MATLAB 명령에 해당하는 링크를 클릭했습니다.
명령을 실행하려면 MATLAB 명령 창에 입력하십시오. 웹 브라우저는 MATLAB 명령을 지원하지 않습니다.
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