Still didn't work for me without cbind , although you really don't need it ;)
worked after i set options(stringsAsFactors=F).
> options(stringsAsFactors=F)
> df<-data.frame(intVec,chaVec)
> df
intVec chaVec
1 1 a
2 2 b
3 3 c
> df$chaVec
[1] "a" "b" "c"
documentation of data.frame says the option is true by default.
Am 10.04.2012 um 17:38 schrieb R. Michael Weylandt:
> Don't use cbind() -- it forces everything into a single type, here
> string, which in turn becomes factor.
>
> Simply,
>
> data.frame(a, b, c)
>
> Like David mentioned a few days ago, I have no idea who is promoting
> this data.frame(cbind(...)) idiom, but it's a terrible idea (albeit
> one that seems to be very frequent over the last few weeks)
>
> Michael
>
> On Tue, Apr 10, 2012 at 10:33 AM, Anser Chen <anser.c...@gmail.com> wrote:
>> Complete newbie to R -- struggling with something which should be pretty
>> basic. Trying to create a simple data set (which I gather R refers to as a
>> data.frame). So
>>
>>> a <- c(1,2,3,4,5);
>>> b <- c(0.3,0.4,0.5,0,6,0.7);
>>
>> Stick the two together into a data frame (call test) using cbind
>>
>>> test <- data.frame(cbind(a,b))
>>
>> Seems to do the trick:
>>
>>> test
>> a b
>> 1 1 0.3
>> 2 2 0.4
>> 3 3 0.5
>> 4 4 0.6
>> 5 5 0.7
>>>
>>
>> Confirm that each variable is numeric:
>>
>>> is.numeric(test$a)
>> [1] TRUE
>>> is.numeric(test$b)
>> [1] TRUE
>>
>>
>> OK, so far so good. But, now I want to merge in a vector of characters:
>>
>>> c <- c('y1","y2","y3","y4","y5")
>>
>> Confirm that this is string:
>>
>>> is.numeric(c);
>> [1] FALSE
>>
>> cbind c into the data frame:
>>
>>> test <- data.frame(cbind(a,b,c))
>>
>> Looks like everything is in place:
>>
>>> test
>> a b c
>> 1 1 0.3 y1
>> 2 2 0.4 y2
>> 3 3 0.5 y3
>> 4 4 0.6 y4
>> 5 5 0.7 y5
>>
>> Except that it seems as if the moment I cbind in a character vector, it
>> changes numeric data to string:
>>
>>> is.numeric(test$a)
>> [1] FALSE
>>> is.numeric(test$b)
>> [1] FALSE
>>
>> which would explain why the operations I'm trying to perform on elements of
>> a and b columns are failing. If I look at the structure of the data.frame,
>> I see that in fact *all* the variables are being entered as "factors".
>>
>>> str(test)
>> 'data.frame': 5 obs. of 3 variables:
>> $ a: Factor w/ 5 levels "1","2","3","4",..: 1 2 3 4 5
>> $ b: Factor w/ 5 levels "0.3","0.4","0.5",..: 1 2 3 4 5
>> $ c: Factor w/ 5 levels "y1","y2","y3",..: 1 2 3 4 5
>>
>> But, if I try
>>
>> test <- data.frame(cbind(a,b))
>>> str(test)
>> 'data.frame': 5 obs. of 2 variables:
>> $ a: num 1 2 3 4 5
>> $ b: num 0.3 0.4 0.5 0.6 0.7
>>
>> a and b are coming back as numeric. So, why does cbind'ing a column of
>> character variables change everything else? And, more to the point, what do
>> I need to do to 'correct' the problem (i.e., stop this from happening).
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help@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.
>
> ______________________________________________
> R-help@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.
[[alternative HTML version deleted]]
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