VAR Variance Function
Section: Elementary Functions
UsageComputes the variance of an array along a given dimension. The general syntax for its use is
y = var(x,d)
x is an
n-dimensions array of numerical type.
The output is of the same numerical type as the input. The argument
d is optional, and denotes the dimension along which to take
the variance. The output
y is the same size as
that it is singular along the mean direction. So, for example,
x is a
3 x 3 x 4 array, and we compute the mean along
d=2, then the output is of size
3 x 1 x 4.
Function InternalsThe output is computed via
d is omitted, then the mean is taken along the
first non-singleton dimension of
ExampleThe following piece of code demonstrates various uses of the var function
--> A = [5,1,3;3,2,1;0,3,1] A = 5 1 3 3 2 1 0 3 1
We start by calling
var without a dimension argument, in which
case it defaults to the first nonsingular dimension (in this case,
along the columns or
d = 1).
--> var(A) ans = 6.3333 1.0000 1.3333
Next, we take the variance along the rows.
--> var(A,2) ans = 4.0000 1.0000 2.3333