R help - Mar 2012 - Classification by range

Given

studentNumbers<-10;

subjEnglish<-sample(-1:100,studentNumbers,replace=TRUE);

when subEnglish <=0, 'U'
                        <=39, 'F'
                        <=49 'D'
                        <=59, 'C'
                        <=69, 'B'
                        <=79,'A'
                        <=100 'A+'
I can solve this using a series of 'if' 'else' statements. I am
looking for a simple expression that will give the letter classification for
every element of subEnglish.


Is there on?

Thanks.

	[[alternative HTML version deleted]]

?findInterval
> subjEnglish<-sample(-1:100,studentNumbers,replace=TRUE);
> grade <- c(-Inf, 39, 49, 59, 69, 79, 100)  # grade break points
> let <- c("U", "F", "D", "C",
"B", "A", "A+")[findInterval(subjEnglish, grade)]
> cbind(subjEnglish, let)
      subjEnglish let
 [1,] "77"        "B"
 [2,] "93"        "A"
 [3,] "52"        "D"
 [4,] "19"        "U"
 [5,] "91"        "A"
 [6,] "99"        "A"
 [7,] "33"        "U"
 [8,] "83"        "A"
 [9,] "20"        "U"
[10,] "5"         "U"
>

On Thu, Mar 8, 2012 at 3:14 PM, Ajay Askoolum <aa2e72e at yahoo.co.uk>
wrote:
> Given
>
> studentNumbers<-10;
>
> subjEnglish<-sample(-1:100,studentNumbers,replace=TRUE);
>
> when subEnglish <=0, 'U'
> ??????????????????????? <=39, 'F'
> ??????????????????????? <=49 'D'
> ??????????????????????? <=59, 'C'
> ??????????????????????? <=69, 'B'
> ??????????????????????? <=79,'A'
> ??????????????????????? <=100 'A+'
> I can solve this using a series of 'if' 'else' statements.
I am looking for a simple expression that will give the letter classification
for every element of subEnglish.
>
>
> Is there on?
>
> Thanks.
>
> ? ? ? ?[[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.

On Mar 8, 2012, at 3:14 PM, Ajay Askoolum wrote:
> Given
>
> studentNumbers<-10;
>
> subjEnglish<-sample(-1:100,studentNumbers,replace=TRUE);
>
> when subEnglish <=0, 'U'
>                         <=39, 'F'
>                         <=49 'D'
>                         <=59, 'C'
>                         <=69, 'B'
>                         <=79,'A'
>                         <=100 'A+'
> I can solve this using a series of 'if' 'else' statements.
I am
> looking for a simple expression that will give the letter  
> classification for every element of subEnglish.
?cut

(This should be explained and exemplified in any introductory material  
regarding R.)

-- 

David Winsemius, MD
West Hartford, CT