Re: Weird result returned from adding floats depending on order I add them

On Feb 21, 2:05 am, Grant Edwards <gra...@xxxxxxxx> wrote:
On 2007-02-20, joanne matthews (RRes-Roth) <joanne.matth...@xxxxxxxxxxx> wrote:

I'm getting different results when I add up a list of floats depending
on the order that I list the floats.


Don't use floating point if you expect exact results.

It's not the floating point that's the problem, it's the radix, in
this case 2, not being able to express n/10 exactly. As the tutorial
points out, radix-10 has problems representing n/3 (and n/7 and ...)
exactly.

Another take: Don't expect exact results. If the input is exact to 1
or two decimal places, don't expect the sum to be exact to 15 or more
decimal places.

.

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