Formatting numbers for display
On Aug 2, 2012, at 8:27 PM, arun wrote:
For your first condition, this could be used:
gsub("(\\d)[.].*","\\1",498888888.85)
[1] "498888888"
Second condition:
formatC(4333.78889,width=8,format="f",digits=2,flag="0")
#[1] "04333.79"
formatC(884333.78889,width=8,format="f",digits=2,flag="0")
#[1] "884333.79"
Third condition:
sprintf("%.3f",0.0123556)
#[1] "0.012"
I didn't get the same results as requested with a wider variety of
tests using those formatting methods. Here's what I could offer:
form3 <- function (x) switch(findInterval(x, c( 0, 1, 10^7, Inf)),
format(x, digits=3),
formatC(x, width=8, format="f",
drop0trailing=FALSE),
trunc(x) )
tx <- c( 0.55555555, 55.555555555, 555555555555555.55555555)
> sapply(tx, form3)
[1] "0.556" " 55.5556" "555555555555555"
(Still not getting the 8 digits in the intermediate value cases. Have
not figured out how to get rid of leading space.)
David.
>
> #You can create a function similar to this. (This still have some
> bugs).
>
> fun1<-function(x)
> ifelse(x>10^7,gsub("\\d)[.].*","\\1",x),ifelse(x<10^7 &
> x>1,formatC(x,width=8,format="f",digits=2,flag="0"),sprintf("%.3f",x))
> )
> fun1(488.85)
> #[1] "00488.85"
> fun1(0.1233555)
> #[1] "0.123"
>
Using the vector of long 5's
> sapply(tx, fun1)
[1] "0.556" "00055.56" "555555555555556"
>
> fun1(VALUES)
> # [1] "123456789" "12345678" "1234567.90" "123456.89" "12345.79"
> #[6] "01234.68" "00123.57" "00012.46" "00001.35" "0.123"
> #[11] "0.012" "0.001"
>
>
> A.K.
>
>
>
> ----- Original Message -----
> From: Dennis Fisher <fisher at plessthan.com>
> To: r-help at stat.math.ethz.ch
> Cc:
> Sent: Thursday, August 2, 2012 10:34 PM
> Subject: [R] Formatting numbers for display
>
> Colleagues
>
> R 2.15.1
> OS X
>
> I have a lengthy script that generates a positive number that I
> display in a graphic using text. The range of possible values is
> quite large and I am looking for an efficient means to format.
> 1. If the number is large (e.g., > 10^7), I want to display
> only the integer portion.
> 2. If it is less than 10^7 but > 1, I want to display 8
> characters, e.g.,
> 12345.78
> 1234.678
> 123.5678
> 3. If it is less than 1, I want to display at least three
> significant digits, e.g.
> 0.123
> 0.0123
> 0.00123
> 0.000123
> If there are any inconsistencies in my proposal, I apologize.
>
> I can accomplish this by brute force with conditionals, -
> ceiling(log10(VALUE)), round. However, I expect that there is a
> more efficient approach, possibly using sprint.
>
> For the "dput"-ers, use the following as potential input:
> VALUES <- c(123456789, 12345678, 1234567.9, 123456.89, 12345.789,
> 1234.6789, 123.56789, 12.456789, 1.3456789, 0.123456789,
> 0.0123456789, 0.00123456789)
>
> Thanks for any thoughts.
>
> Dennis
>
> Dennis Fisher MD
David Winsemius, MD
Heritage Laboratories
West Hartford, CT