[R] Coercing of types when raising a number to a series of powers

[Nordlund, Dan (DSHS/RDA)]

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Julio Sergio
> Sent: Thursday, February 07, 2013 6:13 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Coercing of types when raising a number to a series of
> powers
> 
> I'm trying to produce a series of powers of a number as follows:
> 
>   |> 0.05^0:5
>    [1] 1 2 3 4 5
> 
> This is not the result I expected. I guess some kind of coercion
> happened,
> since,
> 
>   |> class(0.05^0:5)
>    [1] "integer"
> 
> Could anyone explain me what is happening here?
> 
> Thanks,
> 
>   -Sergio.
> 

It has to do with operator precedence.  '^' has higher precedence than ':'.  What you typed 

   0.05^0:5

Was evaluated as 

   (0.5^0):5

What you should have typed was 

   0.05^(0:5)


Hope this is helpful,

Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA 98504-5204