Problem with floor

Is the below is a known issue? if so any workarounds?

test1 = 500 * 1.001
test2 = test1 * 10.0
(Now value of test2 is 5005.0)
floor(test2) will give 5004.

 

See countless posts before on similar subjects. This is a standard floating
point rounding problem - which occurs in pretty much all high level languages
(including C).

If you do:

sstatus(fullPrecision t)
test2 => 5004.999999999999
printf("%.12f" test2)
test2-5005.0 => -9.094947e-13

The problem is caused by the fact that floating point numbers are represented
with a finite binary mantissa, and so 1.001 is a recurring fraction (should be
infinitely recurring, but is truncated due to the finite precision). When
multipled, you end up with rounding errors (small, but still noticeable if you
look).

To avoid this either use round(), or use a small tolerance added to the value
before you floor it.

Andrew.

 

Hi Pradeep, please try this any any other programming language you can
get your hands on. You should get
the same results in Perl, Python, Java, C, C++, Fortran
or anything i can think of.

Try it out and let me know what answer you get and with other language
you are are using.

-jim