I have a simple function defined as follows,
a = 0.4;
b = 120;
c = 120;
index = 2*a*b*(c-2*a*c) + 2*a*c*(b-2*a*b) + 4*a*c*a*b;
The variable index is then used as an index number of elements in a vector, thus should be an integer. However, the above function gives me index = 1.382400000000000e+04 which is double instead of 13824 as an integer, and I cannot used it as index in a vector. If I set a = 0.3 or 0.5 this will not occur. a is actually varied from 0.1 to 0.5 in a step of 0.1. Any idea why this would occur for a = 0.4? Thank you in advance!