MATLAB Function Reference |
Determine if all array elements are nonzero
Syntax
Description
B = all(A)
tests whether all the elements along various dimensions of an array are nonzero or logical 1
(true
).
If A
is a vector, 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 matrix, all(A)
treats the columns of A
as vectors, returning a row vector of logical 1
's and 0
's.
If A
is a multidimensional array, all(A)
treats the values along the first nonsingleton dimension as vectors, returning a logical condition for each vector.
B = all(A,
tests along the dimension of dim
)
A
specified by scalar dim
.
Examples
then B = (A < 0.5)
returns logical 1
(true
) only where A
is less than one half:
The all
function reduces such a vector of logical conditions to a single condition. In this case, all(B)
yields 0
.
This makes all
particularly useful in if
statements:
where code is executed depending on a single condition, not a vector of possibly conflicting conditions.
Applying the all
function twice to a matrix, as in all(all(A))
, always reduces it to a scalar condition.
See Also
any
, logical operators (elementwise and short-circuit), relational operators, colon
Other functions that collapse an array's dimensions include max
, mean
, median
, min
, prod
, std
, sum
, and trapz
.
alim | allchild |
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