Find multiple true in same row

I am trying to detect if there is more than one true in the same column of a matrix:

A=[1 0 0; 1 0 0]

r= sum(A,2);
check=sum(r>1)

if check ==0
    out= 'single';
else
    out='multiple';

but it does not work I do not understand why? And to achieve the same for columns I have used:

col= sum(A);
check=sum(col>1)

if check ==0
    out= 'single'
else
    out='multiple'

this seems to work for columns.

Is there a better way to check separately if there are multiple true in rows and columns?

Answer 1

[per isakson]

Hint:

>> A=[1 0 0; 1 0 1]
A =
     1     0     0
     1     0     1
>> B = A==1
B =
     1     0     0
     1     0     1
>> sum( B, 1 )
ans =
     2     0     1
>> sum( B, 2 )
ans =
     1
     2
>>

with A(end,end)==1

[Millone]

Thanks for the hint