(a + b) + c ≠ a + (b + c)

I'm new to Matlab

Is there any way to find a, b and c so that (a + b) + c ≠ a + (b + c) I know addition is not associative in floating point, but is there any way to do that in Matlab?

Answer 1

[David Goodmanson]

Hi peluca6,

try 0.1 0.2 0.3

These situations are not hard to find. If you just take three random floating point numbers between 0 and 1,

a = rand
b = rand
c = rand

(to make a vector or matrix of random numbers, see 'help rand') and take a look at the quantity

((a+b)+c) - (a+(b+c))

it is nonzero about 17% if the time.