Hello, Thank you for your help. However the dataframes I gave you were only
examples, the actual dataframes are very big. Does this mean I have to
write every range of data for each variable??


On Fri, Apr 26, 2013 at 2:25 PM, Rui Barradas <ruipbarradas@sapo.pt> wrote:

> Hello,
>
> The following seems to do the trick.
>
>
>
> x1 <-
> structure(list(State_prov = c("Nova Scotia", "Nova Scotia", "Nova Scotia"
> ), Shape_name = c("Annapolis", "Antigonish", "Gly"), bob2009 = c(0L,
> 0L, NA), bob2010 = c(0L, 0L, NA), bob2011 = c(1L, 0L, NA)), .Names =
> c("State_prov",
> "Shape_name", "bob2009", "bob2010", "bob2011"), class = "data.frame",
> row.names = c(NA,
> -3L))
>
> x2 <-
> structure(list(FID = 0:2, State_prov = c("Nova Scotia", "Nova Scotia",
> "Nova Scotia"), Shape_name = c("Annapolis", "Antigonish", "Gly"
> ), bob2009 = c(0L, 0L, 0L), bob2010 = c(0L, 0L, 0L), coy2009 = c(10L,
> 1L, 1L)), .Names = c("FID", "State_prov", "Shape_name", "bob2009",
> "bob2010", "coy2009"), class = "data.frame", row.names = c(NA,
> -3L))
>
> x3  <- merge(x1, x2, all.y = TRUE)
>
>
>
> Note also that since by = intersect(names(x1), names(x2)), you really
> don't need it, it's the default behavior.
>
> Hope this helps,
>
> Rui Barradas
>
> Em 26-04-2013 18:10, Catarina Ferreira escreveu:
>
>  Dear all,
>>
>> I'm trying to merge 2 dataframes, but I'm not being entirely successful
>> and
>> I can't understand why.
>>
>> Dataframe x1
>>
>> State_prov     Shape_name   bob2009   bob 2010   bob2011
>> Nova Scotia    Annapolis         0                  0              1
>> Nova Scotia    Antigonish        0                  0              0
>> Nova Scotia    Gly                   NA               NA             NA
>>
>> Dataframe x2 - has 20000 rows and 193 variables, contains one important
>> field which is "FID" that is a link to a shapefile (this is not in x1) and
>> shares common columns with x1, like this:
>>
>> FID     State_prov     Shape_name   bob2009   bob 2010  coy 2009
>>   0        Nova Scotia    Annapolis         0
>> 0              10
>>   1        Nova Scotia    Antigonish        0
>> 0              1
>>   2        Nova Scotia    Gly                   0
>> 0              1
>>
>> So when I do
>>
>> x3  <- merge(x1, x2, by=intersect(names(x1), names(x2)), all=TRUE)
>>
>> it should do the trick. The thing is that it works for the columns (it
>> adds
>> all the new columns not common to both dataframes), but it also adds the
>> rows. This is what I get (x3):
>>
>> FID     State_prov     Shape_name   bob2009   bob 2010  coy 2009   bob2011
>>   0        Nova Scotia    Annapolis         0
>> 0              10            NA
>>   NA      Nova Scotia    Annapolis         NA               NA          NA
>>              1
>>   1        Nova Scotia    Antigonish        0
>> 0              1               NA
>> NA      Nova Scotia    Antigonish        NA               NA          NA
>>              0
>>   2        Nova Scotia    Gly                   0
>> 0              1               NA
>> NA      Nova Scotia    Gly                   NA               NA
>> NA             NA
>>
>> What I want to get is a true merge, like this:
>>
>> FID     State_prov     Shape_name   bob2009   bob 2010  coy 2009   bob2011
>>   0        Nova Scotia    Annapolis         0
>> 0              10            1
>>   1        Nova Scotia    Antigonish        0
>> 0              1               0
>>   2        Nova Scotia    Gly                   0
>> 0              1               NA
>>
>> Can anybody please help me to understand what I'm doing wrong.
>> Any help will be much appreciated!!
>>
>>
>>


-- 
Catarina C. Ferreira, PhD
Post-doctoral Research Fellow
Department of Biology
Trent University
Peterborough, ON Canada
URL: http://www.researcherid.com/rid/A-3898-2011

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