Odp: ^ operator

but with complex, I get complex numbers for the first and last elements:

  

(as.complex(tmp))^(1/3)
    

[1] 0.01969170+0.03410703i 0.03478442+0.00000000i 0.03285672+0.00000000i
[4] 0.08950802+0.00000000i 0.05848363+0.10129661i

whereas for the first element, we get the followings.

Moreover, 
  

-6.108576e-05^(1/3)
 [1] -0.03938341
    

and
  

-(6.108576e-05^(1/3))
    

[1] -0.03938341
and
 -((6.108576e-05)^(1/3))
[1] -0.03938341

give the same results.

so using () doesn't preserve any thing

--- On Mon, 11/16/09, Petr PIKAL <petr.pikal at precheza.cz> wrote:

  

From: Petr PIKAL <petr.pikal at precheza.cz>
Subject: Odp: [R] ^ operator
To: "carol white" <wht_crl at yahoo.com>
Cc: r-help at stat.math.ethz.ch
Date: Monday, November 16, 2009, 3:40 AM
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


    

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