min

Minimum elements of an array

Syntax

M = min(A)

M = min(A,[],dim)

M = min(A,[],nanflag)

M = min(A,[],dim,nanflag)

[M,I] = min(___)

M = min(A,[],'all')

M = min(A,[],vecdim)

M = min(A,[],'all',nanflag)

M = min(A,[],vecdim,nanflag)

C = min(A,B)

C = min(A,B,nanflag)

Description

M = min(A) returns the minimum elements of an array.

• If A is a vector, then min(A) returns the minimum of A.

• If A is a matrix, then min(A) is a row vector containing the minimum value of each column.

• If A is a multidimensional array, then min(A) operates along the first array dimension whose size does not equal 1, treating the elements as vectors. The size of this dimension becomes 1 while the sizes of all other dimensions remain the same. If A is an empty array with first dimension 0, then min(A) returns an empty array with the same size as A.

M = min(A,[],dim) returns the smallest elements along dimension dim. For example, if A is a matrix, then min(A,[],2) is a column vector containing the minimum value of each row.

M = min(A,[],nanflag) specifies whether to include or omit NaN values in the calculation. For example, min(A,[],'includenan') includes all NaN values in A while min(A,[],'omitnan') ignores them.

M = min(A,[],dim,nanflag) also specifies the dimension to operate along when using the nanflag option.

[M,I] = min(___) finds the indices of the minimum values of A and returns them in output vector I, using any of the input arguments in the previous syntaxes. If the minimum value occurs more than once, then min returns the index corresponding to the first occurrence.

M = min(A,[],'all') finds the minimum over all elements of A.

M = min(A,[],vecdim) computes the minimum over the dimensions specified in the vector vecdim. For example, if A is a matrix, then min(A,[],[1 2]) computes the minimum over all elements in A, since every element of a matrix is contained in the array slice defined by dimensions 1 and 2.

M = min(A,[],'all',nanflag) computes the minimum over all elements of A when using the nanflag option.

M = min(A,[],vecdim,nanflag) specifies multiple dimensions to operate along when using the nanflag option.

C = min(A,B) returns an array with the smallest elements taken from A or B.

C = min(A,B,nanflag) also specifies how to treat NaN values.

Examples

Smallest Vector Element

Create a vector and compute its smallest element.

A = [23 42 37 15 52];
M = min(A)

M = 15

Smallest Complex Element

Create a complex vector and compute its smallest element, that is, the element with the smallest magnitude.

A = [-2+2i 4+i -1-3i];
min(A)

ans = -2.0000 + 2.0000i

Smallest Element in Each Matrix Column

Create a matrix and compute the smallest element in each column.

A = [2 8 4; 7 3 9]

A = 2×3

     2     8     4
     7     3     9

M = min(A)

M = 1×3

     2     3     4

Smallest Element in Each Matrix Row

Create a matrix and compute the smallest element in each row.

A = [1.7 1.2 1.5; 1.3 1.6 1.99]

A = 2×3

    1.7000    1.2000    1.5000
    1.3000    1.6000    1.9900

M = min(A,[],2)

M = 2×1

    1.2000
    1.3000

Smallest Element Indices

Create a matrix A and compute the smallest elements in each column as well as the row indices of A in which they appear.

A = [1 9 -2; 8 4 -5]

A = 2×3

     1     9    -2
     8     4    -5

[M,I] = min(A)

M = 1×3

     1     4    -5

I = 1×3

     1     2     2

Minimum of Array Page

Create a 3-D array and compute the minimum over each page of data (rows and columns).

A(:,:,1) = [2 4; -2 1];
A(:,:,2) = [9 13; -5 7];
A(:,:,3) = [4 4; 8 -3];
M1 = min(A,[],[1 2])

M1 = 
M1(:,:,1) =

    -2


M1(:,:,2) =

    -5


M1(:,:,3) =

    -3

To compute the minimum over all dimensions of an array, you can either specify each dimension in the vector dimension argument, or use the 'all' option.

M2 = min(A,[],[1 2 3])

M2 = -5

Mall = min(A,[],'all')

Mall = -5

Smallest Element Comparison

Create a matrix and return the smallest value between each of its elements compared to a scalar.

A = [1 7 3; 6 2 9]

A = 2×3

     1     7     3
     6     2     9

B = 5;
C = min(A,B)

C = 2×3

     1     5     3
     5     2     5

Smallest Element in Matrix

Create a matrix A and use its column representation, A(:), to find the value and index of the smallest element.

A = [8 2 4; 7 3 9]

A = 2×3

     8     2     4
     7     3     9

A(:)

ans = 6×1

     8
     7
     2
     3
     4
     9

[M,I] = min(A(:))

M = 2

I = 3

I is the index of A(:) containing the smallest element.

Now, use the ind2sub function to extract the row and column indices of A corresponding to the smallest element.

[I_row, I_col] = ind2sub(size(A),I)

I_row = 1

I_col = 2

If you need only the minimum value of A and not its index, call the min function twice.

M = min(min(A))

M = 2

Smallest Element Involving NaN

Create a vector and compute its minimum, excluding NaN values.

A = [1.77 -0.005 3.98 -2.95 NaN 0.34 NaN 0.19];
M = min(A,[],'omitnan')

M = -2.9500

min(A) will also produce this result since 'omitnan' is the default option.

Use the 'includenan' flag to return NaN.

M = min(A,[],'includenan')

M = NaN

Input Arguments

A — Input array

scalar | vector | matrix | multidimensional array

Input array, specified as a scalar, vector, matrix, or multidimensional array.

• If A is complex, then min(A) returns the complex number with the smallest magnitude. If magnitudes are equal, then min(A) returns the value with the smallest magnitude and the smallest phase angle.

• If A is a scalar, then min(A) returns A.

• If A is a 0-by-0 empty array, then min(A) is as well.

If A has type categorical, then it must be ordinal.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | categorical | datetime | duration
Complex Number Support: Yes

dim — Dimension to operate along

positive integer scalar

Dimension to operate along, specified as a positive integer scalar. If no value is specified, then the default is the first array dimension whose size does not equal 1.

Dimension dim indicates the dimension whose length reduces to 1. The size(M,dim) is 1, while the sizes of all other dimensions remain the same, unless size(A,dim) is 0. If size(A,dim) is 0, then min(A,dim) returns an empty array with the same size as A.

Consider a two-dimensional input array, A:

• If dim = 1, then min(A,[],1) returns a row vector containing the smallest element in each column.

  

• If dim = 2, then min(A,[],2) returns a column vector containing the smallest element in each row.

  

min returns A if dim is greater than ndims(A).

vecdim — Vector of dimensions

vector of positive integers

Vector of dimensions, specified as a vector of positive integers. Each element represents a dimension of the input array. The lengths of the output in the specified operating dimensions are 1, while the others remain the same.

Consider a 2-by-3-by-3 input array, A. Then min(A,[],[1 2]) returns a 1-by-1-by-3 array whose elements are the minimums computed over each page of A.

Data Types: double | single | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

B — Additional input array

scalar | vector | matrix | multidimensional array

Additional input array, specified as a scalar, vector, matrix, or multidimensional array. Numeric inputs A and B must either be the same size or have sizes that are compatible (for example, A is an M-by-N matrix and B is a scalar or 1-by-N row vector). For more information, see Compatible Array Sizes for Basic Operations.

If A and B are datetime, duration, or categorical arrays, then they must be the same size unless one is a scalar.

• A and B must be the same data type unless one is a double. In that case, the data type of the other array can be single, duration, or any integer type.

• If A and B are ordinal categorical arrays, they must have the same sets of categories with the same order.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | categorical | datetime | duration
Complex Number Support: Yes

nanflag — NaN condition

'omitnan' (default) | 'includenan'

NaN condition, specified as one of these values:

• 'omitnan' — Ignore all NaN values in the input.

• 'includenan' — Include the NaN values in the input for the calculation.

For datetime arrays, you can also use 'omitnat' or 'includenat' to omit and include NaT values, respectively.

The min function does not support the nanflag option for categorical arrays.

Data Types: char

Output Arguments

M — Minimum values

scalar | vector | matrix | multidimensional array

Minimum values, returned as a scalar, vector, matrix, or multidimensional array. size(M,dim) is 1, while the sizes of all other dimensions match the size of the corresponding dimension in A, unless size(A,dim) is 0. If size(A,dim) is 0, then M is an empty array with the same size as A.

I — Index to minimum values of A

scalar | vector | matrix | multidimensional array

Index to minimum values of A, returned as a scalar, vector, matrix, or multidimensional array. I is the same size as M. If the smallest element occurs more than once, then I contains the index to the first occurrence of the value.

C — Minimum elements from A or B

scalar | vector | matrix | multidimensional array

Minimum elements from A or B, returned as a scalar, vector, matrix, or multidimensional array. The size of C is determined by implicit expansion of the dimensions of A and B. For more information, see Compatible Array Sizes for Basic Operations.

The data type of C depends on the data types of A and B:

• If A and B are the same data type, then C matches the data type of A and B.

• If either A or B is single, then C is single.

• If either A or B is an integer data type with the other a scalar double, then C assumes the integer data type.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function supports tall arrays with the limitation:

• The two-output syntax [Y,I] = min(...) is not supported.

For more information, see Tall Arrays.

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• If you specify dim, then it must be a constant.

• The 'all' option and vecdim argument are not supported.

• See Variable-Sizing Restrictions for Code Generation of Toolbox Functions (MATLAB Coder).

• See Code Generation for Complex Data with Zero-Valued Imaginary Parts (MATLAB Coder).

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

This function fully supports GPU arrays. 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™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).