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Section: Elementary Functions
Reduces a logical array along a given dimension by testing for all logical 1s. The general syntax for its use is
y = all(x,d)
where x
is an n
-dimensions array of logical
type. The output is of logical
type. The argument d
is optional, and denotes the dimension along which to operate. The output y
is the same size as x
, except that it is singular along the operated direction. So, for example, if x
is a 3 x 3 x 4
array, and we all
operation along dimension d=2
, then the output is of size 3 x 1 x 4
.
The output is computed via
If d
is omitted, then the minimum is taken over all elements of x
.
The following piece of code demonstrates various uses of the all
function
--> A = [1,0,0;1,0,0;0,0,1] A = 1 0 0 1 0 0 0 0 1
We start by calling all
without a dimension argument, in which case it defaults to testing all values of A
--> all(A) ans = 0 0 0
The all
function is useful in expressions also.
--> all(A>=0) ans = 1 1 1
Next, we apply the all
operation along the rows.
--> all(A,2) ans = 0 0 0