Checking if a matrix has all its elements filled with one or not?

Suppose I have a matrix like x = [1 1 1 1 1 1]. Now I have to write a if condition, where I have to check whether "x" contains all its elements as ones or not? How to do that. I searched in matlab's help, but couldn't find any direct "command" like to check such an existence.

Answer 1

[Andrei Bobrov]

variant

all(x)

[Abhishek]

suppose I need to find the number of non zero elements in the vector then is there any direct command? thanks for your quick response.

[Abhishek]

@andrei: all(x==1) returns a value 1 even if I have all zeroes as my elements. x = [0 0 0 0 0 0] which should not be the case, right?

[Walter Roberson]

>> x = [0 0 0 0 0 0]

x =

0 0 0 0 0 0

>> all(x==1)

ans =

0

So if you are getting a 1 result from that, something is wrong.

The number of non-zero elements is nnz(x)

The original answer of all(x) does not match your problem conditions, as it would return true for the situation in which all of the x are non-zero. Your variation of all(x==1) is correct for vectors. For general matrices, all(x(:)==1)

A variation would be isequal(x, ones(size(x),class(x))