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

[David Winsemius]

On Feb 7, 2013, at 6:21 PM, Julio Sergio wrote:

> Julio Sergio <juliosergio <at> gmail.com> writes:
> 
>> 
>> I'm trying to produce a series of powers of a number as follows:
>> 
>>  |> 0.05^0:5
> 
> 
> I'm sorry for the question. The answer is simple: the result is due to
> operator precedence not to coercing:
> 
>  |> 0.05^(0:5)
>  [1] 1.000e+00 5.000e-02 2.500e-03 1.250e-04 6.250e-06 3.125e-07

You might want to review the rest of the R0FAQ: The item regarding operator precedence is actually about the higher precedence of "^" relative to the minus sign, but there are a lot of goodies in section 7:

FAQ 7:31 shows how you can see what the parsed expression looks like:

> as.list(quote(-2^2))
     [[1]]
     `-`
     
     [[2]]
     2^2

In your case it's:

> as.list(quote( 0.05^0:5 )  )
[[1]]
`:`

[[2]]
0.05^0   

[[3]]
[1] 5

-- 
David Winsemius
Alameda, CA, USA