Message-ID: <OF5252E865.EE59D0A0-ONC1257670.003F96DF-C1257670.004022AB@precheza.cz>
Date: 2009-11-16T11:40:29Z
From: PIKAL Petr
Subject: Odp: ^ operator
In-Reply-To: <150505.22665.qm@web62003.mail.re1.yahoo.com>
Hi
AFAIK, this is issue of the preference of operators.
r-help-bounces at r-project.org napsal dne 16.11.2009 11:24:59:
> Hi,
> I want to apply ^ operator to a vector but it is applied to some of the
> elements correctly and to some others, it generates NaN. Why is it not
able to
> calculate -6.108576e-05^(1/3) even though it exists?
>
>
> tmp
> [1] -6.108576e-05 4.208762e-05 3.547092e-05 7.171101e-04
-1.600269e-03
> > tmp^(1/3)
> [1] NaN 0.03478442 0.03285672 0.08950802 NaN
This computes (-a)^(1/3) which is not possible in real numbers. You have
to use as.complex(tmp)^(1/3) to get a result.
> > -6.108576e-05^(1/3)
> [1] -0.03938341
this is actually
-(6.108576e-05^(1/3))
Regards
Petr
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.