Data arithmatic addition with single precision

Hello

I am adding 21 elements of an array by two different methods. The two methods should show same value. But while printing the results the are different. Please suggest.

clc
clear all
close all

x=rand(1,100)*10^16;
x = single(x)
method1  = sum(x(1:21))+x(22)-x(1);
method2 = sum(x(2:22));
sprintf('%f',method1)
sprintf('%f',method2)

Regards,

Gagarin

Answer 1

[James Tursa]

Floating point operations will often yield slightly different results if you change the order of operations. This is to be expected.

https://www.mathworks.com/matlabcentral/answers/57444-faq-why-is-0-3-0-2-0-1-not-equal-to-zero