[R] Fwd: Questions about working with a dataframe

[David Winsemius]

On Jun 25, 2013, at 8:57 AM, John Kane wrote:

> Hi, welcome to R
> 
> Try using the function str() on both files so str(WWA) and str(oWWA) and compare the structures that you get.  Probably one of the varables you defined when creating the original WWA data set has changed from a character variable to a factor or vis versa.
> 
> It is a good idea to use dput to supply sample data here.
> 
> So dput(WWA) and paste the results into the email and repeat with the other data set.  Then readers can paste the actual data sets into R and work on them directly.  

In this case I think it would be much more courteous to include:

dput(head(WWA)) 
dput(head(oWWA))

... in light of the attached 5MB file in that email. 

I apologize to the other list readers for approving it in the moderation queue. It should ahve been rejected, but my excuse is that the moderation viewer doesn't always highlight all aspects of hte postings being viewed that should be highlighted.

-- 
David.
> If the str() approach does not give you enough information please paste in the dput results in your next email.
> 
> Good luck
> 
> John Kane
> Kingston ON Canada
> 
> 
>> -----Original Message-----
>> From: jacqueline.oehri at gmx.ch
>> Sent: Tue, 25 Jun 2013 16:25:59 +0200
>> To: r-help at r-project.org
>> Subject: [R] Fwd: Questions about working with a dataframe
>> 
>> 
>> 
>>> Dear R-Users,
>>> I hope this is the right e-mail adress to post questions about
>>> Programming in R, and I hope somebody of you can help me with the
>>> troubles I have :)
>>> 
>>> 
>>> 1) First Question:
>>> 
>>> I have a dataframe called "WWA" (its attached to this e-mail
>>> ). It looks a little bit like the following one:
>>> 
>>> 
>>> testcoordID testcommunity testaltitude     testSpeciesName
>>> 1      503146       Bournes        523.2     Bellis perennis
>>> 2      503146       Bournes        321.5 Cynosurus cristatus
>>> 3      557154       Bournes        654.1   Festuca pratensis
>>> 4      557154         Aigle        938.6     Bellis perennis
>>> 5      569226         Aigle        401.3     Bellis perennis
>>> 6      599246         Aigle        765.9   Prunella vulgaris
>>> 
>>> ((I programmed this little one like this:
>>> testcoordID
>>> <-c(as.integer("503146"),as.integer("503146"),as.integer("557154"),as.integer("557154"),as.integer("569226"),as.integer("599246"))
>>> testcommunity <-factor(c("Bournes","Bournes","Bournes", "Aigle",
>>> "Aigle", "Aigle"))
>>> testaltitude <- c(523.2,321.5,654.1,938.6,401.3,765.9)
>>> testSpeciesName <-c( "Bellis perennis",
>>>                     "Cynosurus cristatus",
>>>                     "Festuca pratensis",
>>>                    "Bellis perennis",
>>>                    "Bellis perennis",
>>>                     "Prunella vulgaris")
>>> testframe <- data.frame(testcoordID,testcommunity,testaltitude,
>>> testSpeciesName))
>>> 
>>> 
>>> 
>>> I needed to manipulate WWA in Excel, therefore i wrote
>>> it as a text-file:
>>> 
>>>> write.table(WWA, "WWA.txt", col.names=T, row.names=F, sep= ";", quote
>>>> =T)
>>> 
>>> Then I manipulated the WWA.txt in Excel and saved it as "noWWA.csv"(
>>> ) and re-importet it under the new name "oWWA" in R:
>>> 
>>>> oWWA <- read.csv("~/Desktop/NCCR master projekt/BDM Beschreibungen/BDM
>>>> Daten/noWWA.csv", header=TRUE, sep=";")
>>> 
>>> What i need to do with this "WWA" or "oWWA"is finally to create a list
>>> (or a dataframe but this is not possible i think), that shows for each
>>> coordinateID ("testcoordID") the species Names occuring at this place:
>>> 
>>>> species_per_coordID1<- tapply((WWA$speciesName), WWA$coordID, list)
>>>> species_per_coordID2 <- split(WWA$speciesName, WWA$coordID)
>>> 
>>> ---> now my Question: This works very well with the WWA table, but not
>>> with the oWWA!! I think i changed something in the dataframe by
>>> converting it to a .txt file and than back to a .csv;
>>> But does anybody know why it works with WWA and not with oWWA? how can I
>>> treat the WWA dataframe in Excel without changing any format of it?
>>> 
>>> 
>>> Thaanks a lot for any help or suggestions!!!!!
>>> 
>>> Have a nice day,
>>> 
>>> Kind regards Jacqueline
>>> 


David Winsemius
Alameda, CA, USA