Finding values that aren't in an array in octave

[Rick T]

I have two arrays in octave, a1 is calculated and a2 is given. How can I create a 3rd array a3 that compares a1 to a2 and shows the values that are missing in a1?

a1=[1,4,5,8,13]


a2=[1,2,3,4,5,6,7,8,9,10,11,12,13]


a3=[3,6,7,9,10,11,12,13]

Also can this work for a floating point number say if a1=[1,4,5,8.6,13] or would I have to convert a1 to integers only.

Thanks

--