[R] Adding SORT to UNIQUE

Stephen H. Dawson, DSL @erv|ce @end|ng |rom @hd@w@on@com
Mon Dec 20 22:25:00 CET 2021


Thanks for the reply.

sort(unique(Data[1]))
Error in `[.data.frame`(x, order(x, na.last = na.last, decreasing = 
decreasing)) :
   undefined columns selected

The recommended syntax did not work, as listed above.


*Stephen Dawson, DSL*
/Executive Strategy Consultant/
Business & Technology
+1 (865) 804-3454
http://www.shdawson.com <http://www.shdawson.com>


On 12/20/21 12:15 PM, Avi Gross via R-help wrote:
> Stephen,
>
> You can sort using sort() either before or after doing a unique. Unique
> removes all duplicates in any order so sorting before may be wasteful. in
> your data shown below, do this:
>
> sort(unique(Data[1]))
> sort(unique(Data[2]))
> sort(unique(Data[3]))
> sort(unique(Data[4]))
>
> Even simpler is to define a function like this:
>
> unisort <- function(vec) sort(unique(vec))
>
> and use it like this:
>
> unisort(Data[1])
>
>
> And since you seem to want all of the first four columns of Data you may
> want to do them all at once using something like:
>
> lapply(Data[1:4], unisort)
>
> As you note, the sort ordering depends on the data and perhaps on options
> you specify.
>
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Stephen H. Dawson,
> DSL via R-help
> Sent: Monday, December 20, 2021 11:59 AM
> To: Stephen H. Dawson, DSL via R-help <r-help using r-project.org>
> Subject: [R] Adding SORT to UNIQUE
>
> Hi,
>
>
> Running a simple syntax set to review entries in dataframe columns. Here is
> the working code.
>
> Data <- read.csv("./input/Source.csv", header=T)
> describe(Data)
> summary(Data)
> unique(Data[1])
> unique(Data[2])
> unique(Data[3])
> unique(Data[4])
>
> I would like to add sort the unique entries. The data in the various columns
> are not defined as numbers, but also text. I realize 1 and 10 will not sort
> properly, as the column is not defined as a number, but want to see what I
> have in the columns viewed as sorted.
>
> QUESTION
> What is the best process to sort unique output, please?
>
>
> Thanks.
> --
> *Stephen Dawson, DSL*
> /Executive Strategy Consultant/
> Business & Technology
> +1 (865) 804-3454
> http://www.shdawson.com <http://www.shdawson.com>
>
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> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
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