[R] Help using order with data.frame

[arun]

Hi,
Try:


 data_test<-data.frame(id, dates, info, sqfootage, lotsize,stringsAsFactors=FALSE)
 data_test[order(with(data_test,as.Date(dates,"%m/%d/%Y"))),]
   id     dates   info sqfootage lotsize
3 ID3 2/03/2013 siding      3000    0.75
2 ID2 1/16/2014   wood      2000    0.50
1 ID1 2/16/2014  brick      1000    0.25
4 ID4 4/20/2014  straw      2500    1.00
A.K.






On Sunday, March 16, 2014 5:50 PM, Jason Rupert <jasonkrupert at yahoo.com> wrote:


Thank you very much for your posts.  I updated the example, which was taken from the following:
http://cran.r-project.org/doc/contrib/Torfs+Brauer-Short-R-Intro.pdf

Hopefully the below is a bit more representative question, but unfortunately, it looks like I'm not inputting the dates information properly to the order information

In the way I'm currently inputting dates, order is not able to order the dates properly.   Again I'm stumbling over subtleties of the R syntax.  Again thanks for any guidance, advice, references to addressing ordering dates information.  

Thanks again.  

id<-c("ID1",  "ID2",  "ID3",  "ID4")
info<-c("brick",  "wood",  "siding",  "straw")
sqfootage<-c(1000, 2000,
3000, 2500)
lotsize<-c(0.25, 0.5, 0.75, 1.0)
data_test<-data.frame(id, dates, info, sqfootage, lotsize)
data_test_sorted<-data_test[order(data_test$dates),]
data_test_sorted

   id     dates   info sqfootage lotsize
2 ID2 1/16/2014   wood      2000    0.50
3 ID3 2/03/2013 siding      3000    0.75
1 ID1 2/16/2014  brick      1000    0.25
4 ID4 4/20/2014  straw      2500    1.00
dates
[1] "2/16/2014" "1/16/2014" "2/03/2013" "4/20/2014"


data_test
   id     dates   info sqfootage lotsize
1 ID1 2/16/2014  brick      1000    0.25
2 ID2 1/16/2014   wood     
2000    0.50
3 ID3 2/03/2013 siding      3000    0.75
4 ID4 4/20/2014  straw      2500    1.00

Desire to order the dates information chronologically. 


Thanks again for references to help me understand the proper details of the R syntax (which I love!).  






On Sunday, March 16, 2014 12:14 AM, Jeff Newmiller <jdnewmil at dcn.davis.CA.us> wrote:

It is not order that you are having difficulty with... it is name scope. Your "z" is not a standalone variable, but a column in your "t" data frame.

Try

t[order(t$z), ]

Note that "t" is the name of a commonly-used function in R that transposes matrices. It is generally not a good idea to reuse names like that, but it can be puzzling to avoid when you are new. I type the name of the variable I want to create alone on an interactive R console before I create it... if it tells me that variable is not defined then I proceed.

You should also avoid posting HTML email to this list, as what we see is often not what you see. Read the Posting Guide for more useful advice on using the list.

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On March 15, 2014 9:21:41 PM PDT, Jason Rupert <jasonkrupert at yahoo.com> wrote:
>Evidently, I'm overlooking something simple.� I'm trying to used order
>with data.frame. � 
>
>
>For example: 
>
>t = data.frame(x = c(11,12,14), y = c(19,20,21), z = c(10,9,7))
>t[order(z), ]
>Error in order(z) : object 'z' not found
>
>Thank you for any insights and advice provided. 
>    [[alternative HTML version deleted]]
>
>
>
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