# [R] (no subject)

Uwe Ligges ligges at statistik.tu-dortmund.de
Mon Feb 16 17:29:07 CET 2009

```
Peter Dalgaard wrote:
> Uwe Ligges wrote:
>>
>> Vincze Orsolya wrote:
>>> There are three columns, I was just careless.
>>> I succeed to merge the two tables. But:
>>> 1) in the first table there were rows, which were not present in the
>>> second
>>> table, these rows were deleted from the merged table too, but I need
>>> them.
>>> 2) If i want to import from the second table just a certain column,
>>> not all
>>> that is missing from the first, how can i do that?
>>> 3) How can I save the generated table?
>>>
>>> Sorry about the banal questions.... I'm beginner.
>>> And thanks for the help...
>>> Have a nice day
>>
>> Homework? Then please ask you course material or teacher.
>
> What makes you think that, Uwe? I don't see a teacher asking merge()
> questions to a rank beginner (I wouldn't).

Peter,

at least I give them corresponding homeworks so that they learn about
it: at least merge(), subsetting and assignments are not beyond the
scope of a beginners course in Dortmund. I feel this is a typical 2nd or
3rd day R course homework for data manipulation.

Best,
Uwe

> 1) look at the documentation: all.x=TRUE
> 2) use the usual subsetting mechanisms to work with only the relevant
> set of columns, e.g. merge(x, y[,c(1,2,6)], ....)
> 3) assign using z <- merge(x,y,....), then save() (or maybe write.table())
>
> -pd
>
>
>
>>> 2009/2/15 Peter Dalgaard <p.dalgaard at biostat.ku.dk>
>>>
>>>> Vincze Orsolya wrote:
>>>>
>>>>> Dear all,I had just started to learn R. So my question may sound a bit
>>>>> stupid for you.
>>>>> Is that possible to match and merge two tables in R? I mean I have two
>>>>> tables, in the first I have two columns: RING NUMBER,  WEIGHT and
>>>>> CAPTURE
>>>>>
>>>> Err, ... for large values of "two"? Or is one of the three a rowname?
>>>>
>>>>  DATE, in the second RING NUMBER, SEX  and CAPTURE DATE.
>>>>> 1) First I want to see, if to the ring numbers are the same, the
>>>>> capture
>>>>> dates are too?
>>>>> 2) And second if ring numbers are the same, to import the sex from the
>>>>> second table in the first.
>>>>>
>>>>> Is that possible?
>>>>>
>>>> Yes. It's a job for merge()
>>>>
>>>> --
>>>>   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>>>>  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
>>>>  (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
>>>> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907
>>>>
>>>     [[alternative HTML version deleted]]
>>>
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
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>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>
>

```

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