[R] Built-in function for extracting mantissa and exponent of a numeric

[Rui Barradas]

Hello,

Sorry I forgot to Cc the list.
And I had forgotten the case where x == 0.


extract <- function(x){
	e <- ifelse(x == 0, 0, floor(log10(x)))
	m <- x/10^e
	list(mantissa = m, exponent = e)
}

extract(c(0, 1.234e12, 12345678901234, 123e123))


Hope this helps,

Rui Barradas

Em 23-06-2013 10:54, Søren Højsgaard escreveu:
> Dear all,
>
> Given a number
>
> x<-1.234e12
>
> is there a built-in function for extracting 1.234 and 12 ?
>
> The following "hack" seems clumpsy:
>
>> a<-strsplit(format(x, scientific=T),"e")[[1]]
>> a
> [1] "1.234" "+12"
>> as.numeric(a[1])
> [1] 1.234
>> as.integer(a[2])
> [1] 12
>
> Regards
> Søren
>
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