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.

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 =
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.

Dimension to operate along, specified as a positive integer
scalar. If no value is specified, 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.