[R] a very simple question
Petr Savicky
savicky at cs.cas.cz
Mon Mar 19 09:19:02 CET 2012
On Sun, Mar 18, 2012 at 09:43:54PM +0000, Dajiang Liu wrote:
>
> Dear All,
> I have a seemingly very simple question, but I just cannot figure out the answer. I attempted to run the following:a=0.1*(1:9);which(a==0.3);it returns integer(0). But obviously, the third element of a is equal to 0.3.
> I must have missed something. Can someone kindly explain why? Thanks a lot.
Hi.
A simple way to detect rounding problems is subtracting
the numbers.
a = 0.1*(1:4)
a - 0.3
[1] -2.000000e-01 -1.000000e-01 5.551115e-17 1.000000e-01
Use rounding to avoid it as suggested by others.
Petr Savicky.
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