MATLAB：what's the mean of empty vector？

what's the mean of empty vector？

[Stephen23]

This vector has two elements:

[1,2]

This vector has one element:

[1]

This vector has no elements:

[]

Therefore it is empty.

[Lan]

I know， thanks！

Answer 1

[Star Strider]

A vector with no elements in it. You can create one:

v = [];

or, if the result of an operation, for instance find, has no dlements in an argument vector that meet the logical conditions in it, it will return an empty vector:

v = [1 2 3 4];
f = find(v > 4);

produces:

f =

     Empty matrix: 1-by-0

If you’re talking about the arithmetic mean:

m = mean(f)

the answer is:

m =

               NaN