Octave 4.0.3: normxcorr2 producing unexpected result

[Manuel Reiter]

Hi,

I'm running Octave 4.0.3 from Debian jessie backports on a Raspberry Pi 3. Im 
currently following a computer vision course on Udacity and came across the 
following unexpected behaviour of normxcorr2 (from the image package):

---snip

>> s = [-1 0 0 1 1 1 0 -1 -1 0 1 0 0 -1];
>> t = [1 1 0];
>> x = normxcorr2(t,s)
x =

 Columns 1 through 10:

   1.00000  -0.50000  -0.50000  -1.00000  -0.50000       Inf   1.00000   
0.86603   0.50000  -1.00000

 Columns 11 through 16:

  -0.86603   0.50000   0.50000   1.00000  -0.50000  -0.50000

---snip

I would have expected a vector of length 18 with a max value of 1.0 at position 
7 where the template actually occurs in the pattern. I also don't understand 
why there's a value of 'Inf' in the result, while the documentation states that 
values should range from -1 to 1. I have the feeling that I'm missing something 
obvious here but I really fail to see what that might be. Any help or hints 
greatly appreciated. Thanks in advance!

Greetings,

  Manuel