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false

Logical 0 (false)

Syntax

Description

example

false is shorthand for the logical value 0.

example

F = false(n) is an n-by-n array of logical zeros.

example

F = false(sz) is an array of logical zeros where the size vector, sz, defines size(F). For example, false([2 3]) returns a 2-by-3 array of logical zeros.

example

F = false(sz1,...,szN) is a sz1-by-...-by-szN array of logical zeros where sz1,...,szN indicates the size of each dimension. For example, false(2,3) returns a 2-by-3 array of logical zeros.

example

F = false(___,'like',p) returns an array of logical zeros of the same sparsity as the logical variable p using any of the previous size syntaxes.

Examples

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Use false to generate a 3-by-3 square matrix of logical zeros.

A = false(3)
A =

  3×3 logical array

   0   0   0
   0   0   0
   0   0   0

class(A)
ans =

logical

The result is of class logical.

Use false to generate a 3-by-2-by-2 array of logical zeros.

false(3,2,2)
  3×2×2 logical array

ans(:,:,1) =

   0   0
   0   0
   0   0


ans(:,:,2) =

   0   0
   0   0
   0   0

Alternatively, use a size vector to specify the size of the matrix.

false([3 2 2])
  3×2×2 logical array

ans(:,:,1) =

   0   0
   0   0
   0   0


ans(:,:,2) =

   0   0
   0   0
   0   0

Note that specifying multiple vector inputs returns an error.

false along with true can be used to execute logic statements.

Test the logical statement

  ~(A and B) = (~A) or (~B)

for A = false and B = true.

~(false & true) == (~false) | (~true)
ans =

  logical

   1

The result is logical 1 (true), since the logical statements on both sides of the equation are equivalent. This logical statement is an instance of De Morgan's Law.

Generate a logical array of the same data type and sparsity as the selected array.

A = logical(sparse(5,3));
whos A
  Name      Size            Bytes  Class      Attributes

  A         5x3                41  logical    sparse    

F = false(4,'like',A);
whos F
  Name      Size            Bytes  Class      Attributes

  F         4x4                49  logical    sparse    

The output array F has the same sparse attribute as the specified array A.

Input Arguments

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Size of square matrix, specified as an integer. n sets the output array size to n-by-n. For example, false(3) returns a 3-by-3 array of logical zeros.

  • If n is 0, then F is an empty matrix.

  • If n is negative, then it is treated as 0.

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

Size vector, specified as a row vector of integers. For example, false([2 3)] returns a 2-by-3 array of logical zeros.

  • If the size of any dimension is 0, then F is an empty array.

  • If the size of any dimension is negative, then it is treated as 0.

  • If any trailing dimensions greater than 2 have a size of 1, then the output, F, does not include those dimensions.

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

Size inputs, specified by a comma-separated list of integers. For example, false(2,3) returns a 2-by-3 array of logical zeros.

  • If the size of any dimension is 0, then F is an empty array.

  • If the size of any dimension is negative, then it is treated as 0.

  • If any trailing dimensions greater than 2 have a size of 1, then the output, F, does not include those dimensions.

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

Prototype, specified as a logical variable.

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

Output Arguments

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Output of logical zeros, returned as a scalar, vector, matrix, or N-D array.

Data Types: logical

More About

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Tips

  • false(n) is much faster and more memory efficient than logical(zeros(n)).

See Also

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Introduced before R2006a


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