[R] Use 2 "ifelse" to sort data

Greg Snow Greg.Snow at imail.org
Thu Feb 25 17:49:31 CET 2010


There is the %<% operator in the TeachingDemos package that allows comparisons like:

5 %<% a %<% 10

But in this case it is not needed (and in this case it takes more key strokes than 5 < a & a < 5, so may not be worth it).

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Bill.Venables at csiro.au
> Sent: Monday, February 22, 2010 8:55 PM
> To: tu_chunhao at yahoo.com; r-help at r-project.org
> Subject: Re: [R] Use 2 "ifelse" to sort data
> 
> a <- 1:20
> tt <- ifelse(a > 10, "A", ifelse(a > 5, "B", "C"))
> 
> The problem you have is with '5 < a <= 10'.  Such double sided
> inequalities are used in mathematics but not in R.  Here you only need
> the first part, but if you did need both you would need to write
> 
> 5 < a & a <= 10
> 
> Look carefully and spot the difference.
> 
> Bill Venables
> CSIRO/CMIS Cleveland Laboratories
> 
> 
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Chunhao
> Sent: Tuesday, 23 February 2010 12:13 PM
> To: r-help at r-project.org
> Subject: [R] Use 2 "ifelse" to sort data
> 
> 
> Dear R users,
> I have a question how to use 2 "ifelse" to sort my data. Such as
> from 11 to 20 assign to A; 6 to 10 assign to B, and the rest of them
> assign
> to C
> 
> a<-1:20
> 
> tt<-ifelse(a>10, "A",no=ifelse( 5< a <=10, "B", "C"))
> 
> 
> Many Thanks
> Chunhao
> 
> --
> View this message in context: http://n4.nabble.com/Use-2-ifelse-to-
> sort-data-tp1565422p1565422.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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