Documentation

This is machine translation

Translated by Microsoft
Mouse over text to see original. Click the button below to return to the English verison of the page.

라이선스가 부여된 사용자만 번역 문서를 볼 수 있습니다. 번역 문서를 보려면 로그인하십시오.

all

Determine if all array elements are nonzero or true

Syntax

Description

example

B = all(A) tests along the first array dimension of A whose size does not equal 1, and determines if the elements are all nonzero or logical 1 (true). In practice, all is a natural extension of the logical AND operator.

  • If A is a vector, then all(A) returns logical 1 (true) if all the elements are nonzero and returns logical 0 (false) if one or more elements are zero.

  • If A is a nonempty, nonvector matrix, then all(A) treats the columns of A as vectors and returns a row vector of logical 1s and 0s.

  • If A is an empty 0-by-0 matrix, then all(A) returns logical 1 (true).

  • If A is a multidimensional array, then all(A) acts along the first array dimension whose size does not equal 1 and returns an array of logical values. The size of this dimension becomes 1, while the sizes of all other dimensions remain the same.

example

B = all(A,dim) tests elements along dimension dim. The dim input is a positive integer scalar.

Examples

collapse all

Create a 3-by-3 matrix, and then test each column for all nonzero elements.

A = [0 0 3;0 0 3;0 0 3]
A =

     0     0     3
     0     0     3
     0     0     3

B = all(A)
B =

  1×3 logical array

   0   0   1

Create a vector of decimal values and test which values are less than 0.5.

A = [0.53 0.67 0.01 0.38 0.07 0.42 0.69];
B = (A < 0.5)
B =

  1×7 logical array

   0   0   1   1   1   1   0

The output is a vector of logical values. The all function reduces such a vector of logical values to a single condition. In this case, B = all(A < 0.5) yields logical 0.

This makes all particularly useful in if statements.

  if all(A < 0.5)
      %do something
  else
      %do something else
  end

The code is executed depending on a single condition, rather than a vector of possibly conflicting conditions.

Create a 3-by-7-by-5 multidimensional array and test to see if all of its elements are less than 3.

A = rand(3,7,5) * 5;
B = all(A(:) < 3)
B =

  logical

   0

You can also test the array for elements that are greater than zero.

B = all(A(:) > 0)
B =

  logical

   1

The syntax A(:) turns the elements of A into a single column vector, so you can use this type of statement on an array of any size.

Create a 3-by-3 matrix.

A = [0 0 3;0 0 3;0 0 3]
A =

     0     0     3
     0     0     3
     0     0     3

Test the rows of A for all nonzero elements by specifying dim = 2.

B = all(A,2)
B =

  3×1 logical array

   0
   0
   0

Input Arguments

collapse all

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

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

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.

Consider a two-dimensional input array, A:

  • all(A,1) works on successive elements in the columns of A and returns a row vector of logical values.

  • all(A,2) works on successive elements in the rows of A and returns a column vector of logical values.

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

Output Arguments

collapse all

Logical array, returned as a scalar, vector, matrix, or multidimensional array. The dimension of A acted on by all has size 1 in B.

More About

collapse all

Tall Array Support

This function fully supports tall arrays. For more information, see Tall Arrays.

See Also

| | | |

Introduced before R2006a

Was this topic helpful?