R help - Jun 2015 - subsetting a dataframe

Dear all,

would appreciate your suggestions on subsetting a dataframe : please let's
consider an example dataframe df:

dd<-c(1,2,3)
rows<-c("A1","A2","A3")
columns<-c("B1","B2","B3")
numbers <- c(400, 500, 600)
df <- dataframe(dd,rows,columns, numbers)

and a vector : test_rows <-c("A1","A3") ;

how could I subset the dataframe df function of vector test_rows, in such a
way that only the lines of dataframe df (df$rows) that match the elements
of test_rows ("A1" and "A3") are listed ?

thank you very much,

-- bogdan

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Lots of ways to do this, I use %in% with bracket notation [row, column].
The empty column argument below returns all columns but you could have
conditional logic there as well.

dd[dd$rows %in% test_rows, ]



On Mon, Jun 8, 2015 at 6:44 PM, Bogdan Tanasa <tanasa at gmail.com> wrote:
> Dear all,
>
> would appreciate your suggestions on subsetting a dataframe : please
let's
> consider an example dataframe df:
>
> dd<-c(1,2,3)
> rows<-c("A1","A2","A3")
> columns<-c("B1","B2","B3")
> numbers <- c(400, 500, 600)
> df <- dataframe(dd,rows,columns, numbers)
>
> and a vector : test_rows <-c("A1","A3") ;
>
> how could I subset the dataframe df function of vector test_rows, in such a
> way that only the lines of dataframe df (df$rows) that match the elements
> of test_rows ("A1" and "A3") are listed ?
>
> thank you very much,
>
> -- bogdan
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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]]

Use is.element(elements,set), or its equivalent, elements %in% set:

df <- data.frame(dd = c(1, 2, 3),
                 rows = c("A1", "A2", "A3"),
                 columns = c("B1", "B2", "B3"),
                 numbers = c(400, 500, 600))
test_rows <-c("A1","A3")
df[ is.element(df$rows, test_rows), ]
#  dd rows columns numbers
#1  1   A1      B1     400
#3  3   A3      B3     600


Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Mon, Jun 8, 2015 at 3:44 PM, Bogdan Tanasa <tanasa at gmail.com> wrote:
> Dear all,
>
> would appreciate your suggestions on subsetting a dataframe : please
let's
> consider an example dataframe df:
>
> dd<-c(1,2,3)
> rows<-c("A1","A2","A3")
> columns<-c("B1","B2","B3")
> numbers <- c(400, 500, 600)
> df <- dataframe(dd,rows,columns, numbers)
>
> and a vector : test_rows <-c("A1","A3") ;
>
> how could I subset the dataframe df function of vector test_rows, in such a
> way that only the lines of dataframe df (df$rows) that match the elements
> of test_rows ("A1" and "A3") are listed ?
>
> thank you very much,
>
> -- bogdan
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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]]