Bug: Division by 7

necip · March 2016

Hi, I don't know where I can relay bugreports.

1.0 / 7.0 = 0,14285714285714285714285714285714 (windows calculator)

but Processing 2.0 says

double f = 1.0 / 7.0; println (f);

0.1428571492433548

This is wrong!

koogs · March 2016

your 1.0 and 7.0 are floats.

double f = 1.0 / 7.0; println ("f:" + f);
double d = 1.0d / 7.0d; println ("d:" + d);


f:0.1428571492433548
d:0.14285714285714285

necip · March 2016

Thank you Koogs, but double or not the result of 1/7 is a repetativ sequence of 142857 and this is not given in f : 142857 149243 3548

koogs · March 2016

because computers, specifically the way they handle numbers, is never exact.

doubles are better than floats, as you can see, at the cost of speed and storage space.

how would you write 1/3 as a decimal? computers have the same problem (but using binary).

necip · March 2016

Why I am so currious about the division by 7 is that I am experimenting with numbers and their divisions.

Here are - I hope you can understand german - the results of my excursions

Answers