R help - Jul 2009 - Creating a column based on data in another column

hello all,

I have a data frame and I want to create a column which assigns a letter
based upon the value in another column.  The data column has velocities
ranging from 0 to 1000.  So for example, for velocities between 0 and 300
I'd like to assign the letter "A" in the new column, for 300-600,
"B" and so
on and so forth.  How would I do this?

Thank you very much!

Mehdi Khan

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Dear Medhi,
Take a look at ?cut or ?recode (in the car package).

HTH,

Jorge


On Fri, Jul 31, 2009 at 3:04 PM, Mehdi Khan <> wrote:
> hello all,
>
> I have a data frame and I want to create a column which assigns a letter
> based upon the value in another column.  The data column has velocities
> ranging from 0 to 1000.  So for example, for velocities between 0 and 300
> I'd like to assign the letter "A" in the new column, for
300-600, "B" and
> so
> on and so forth.  How would I do this?
>
> Thank you very much!
>
> Mehdi Khan
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@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.
>
	[[alternative HTML version deleted]]

have a look at ?cut(); for instance,

x <- sample(1000, 20, TRUE)

x
cut(x, c(0, 300, 600, 1000), c("A", "B", "C"))


I hope it helps.

Best,
Dimitris


Mehdi Khan wrote:
> hello all,
> 
> I have a data frame and I want to create a column which assigns a letter
> based upon the value in another column.  The data column has velocities
> ranging from 0 to 1000.  So for example, for velocities between 0 and 300
> I'd like to assign the letter "A" in the new column, for
300-600, "B" and so
> on and so forth.  How would I do this?
> 
> Thank you very much!
> 
> Mehdi Khan
> 
> 	[[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.
> 
-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

Try this:

cut(sample(0:1000, 100), breaks = c(0, 300, 600, 900, 1000), labels =
c('A',
'B', 'C', 'D'))

On Fri, Jul 31, 2009 at 4:04 PM, Mehdi Khan <mwkhan@ucdavis.edu> wrote:
> hello all,
>
> I have a data frame and I want to create a column which assigns a letter
> based upon the value in another column.  The data column has velocities
> ranging from 0 to 1000.  So for example, for velocities between 0 and 300
> I'd like to assign the letter "A" in the new column, for
300-600, "B" and
> so
> on and so forth.  How would I do this?
>
> Thank you very much!
>
> Mehdi Khan
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@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.
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

got it, thank you everyone!

On Fri, Jul 31, 2009 at 12:04 PM, Mehdi Khan <mwkhan@ucdavis.edu> wrote:
> hello all,
>
> I have a data frame and I want to create a column which assigns a letter
> based upon the value in another column.  The data column has velocities
> ranging from 0 to 1000.  So for example, for velocities between 0 and 300
> I'd like to assign the letter "A" in the new column, for
300-600, "B" and so
> on and so forth.  How would I do this?
>
> Thank you very much!
>
> Mehdi Khan
>
	[[alternative HTML version deleted]]

Hey guys, I have the same question, except in reverse: if we had letter
classifications and wanted to assign numerical values to them (the case I
stated previously except the other way around) how would we do that?  I am
trying to use the recode function in the car package but not having any
luck..

Thank you!!

On Fri, Jul 31, 2009 at 12:04 PM, Mehdi Khan <mwkhan@ucdavis.edu> wrote:
> hello all,
>
> I have a data frame and I want to create a column which assigns a letter
> based upon the value in another column.  The data column has velocities
> ranging from 0 to 1000.  So for example, for velocities between 0 and 300
> I'd like to assign the letter "A" in the new column, for
300-600, "B" and so
> on and so forth.  How would I do this?
>
> Thank you very much!
>
> Mehdi Khan
>
	[[alternative HTML version deleted]]