%% Compare Floating-Point Numbers
% Many numbers expressed in decimal text cannot be represented exactly as binary floating numbers. This leads to small differences in results that the ~= operator reflects.
% Perform a few subtraction operations on numbers expressed in decimal and store the result in C.

C = 0.5-0.4-0.1

% With exact decimal arithmetic, C should be equal to exactly 0. Its small value is due to the nature of binary floating-point arithmetic.
%
% Compare C to 0 for inequality.

C ~= 0

%
% Compare floating-point numbers using a tolerance, tol, instead of using ~=.

tol = eps(0.5);
abs(C-0) > tol

% The two numbers, C and 0, are closer to one another than two consecutive floating-point numbers near 0.5. In many situations, C may act like 0.
% Copyright 2012 The MathWorks, Inc.