[R] Ifelse statement on a factor level data frame

[Bert Gunter]

Inline.

Bert Gunter
Genentech Nonclinical Biostatistics
(650) 467-7374

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
Clifford Stoll




On Sun, Sep 28, 2014 at 6:38 AM, Kate Ignatius <kate.ignatius at gmail.com> wrote:
> Strange that,
>
> I did put everything with as.character but all I got was the same...
>
> class of dbpmn[,2]) = factor
> class of dbpmn[,21]  = factor
> class of  dbpmn[,20] = data.frame
>
> This has to be a problem ???

Indeed -- your failure to read documentation.

I suggest you do your due diligence, read Pat Burns's link, and follow
the advice given you by posting a reproducible example. More than
likely the last will be unnecessary as you will figure it out in the
course of doing what you should do.

Cheers,
Bert

>
> I can put reproducible output here but not sure if this going to of
> help here. I think its all about factors and data frames and
> characters...
>
> K.
>
> On Sun, Sep 28, 2014 at 1:15 AM, Jim Lemon <jim at bitwrit.com.au> wrote:
>> On Sun, 28 Sep 2014 12:49:41 AM Kate Ignatius wrote:
>>> Quick question:
>>>
>>> I am running the following code on some variables that are factors:
>>>
>>> dbpmn$IID1new <- ifelse(as.character(dbpmn[,2]) ==
>>> as.character(dbpmn[,(21)]), dbpmn[,20], '')
>>>
>>> Instead of returning some value it gives me this:
>>>
>>> c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1))
>>>
>>> Playing around with the code, gives me some kind of variation to it.
>>> Is there some way to get me what I want.  The variable that its
>>> suppose to give back is a bunch of sampleIDs.
>>>
>> Hi Kate,
>> If I create a little example:
>>
>> dbpmn<-data.frame(V1=factor(sample(LETTERS[1:4],20,TRUE)),
>>   V2=factor(sample(LETTERS[1:4],20,TRUE)),
>>   V3=factor(sample(LETTERS[1:4],20,TRUE)))
>> dbpmn[4]<-
>>  ifelse(as.character(dbpmn[,1]) == as.character(dbpmn[,(2)]),
>>  dbpmn[,3],"")
>> dbpmn
>>    V1 V2 V3 V4
>> 1   B  D  C
>> 2   C  A  D
>> 3   C  B  A
>> 4   A  B  C
>> 5   B  D  B
>> 6   D  D  A  1
>> 7   D  D  D  4
>> 8   B  C  A
>> 9   B  D  B
>> 10  D  C  A
>> 11  A  D  C
>> 12  A  C  B
>> 13  A  A  A  1
>> 14  D  C  A
>> 15  C  D  B
>> 16  A  A  B  2
>> 17  A  C  C
>> 18  B  B  C  3
>> 19  C  C  C  3
>> 20  D  D  D  4
>>
>> I get what I expect, the numeric value of the third element in dbpmn
>> where the first two elements are equal. I think what you want is:
>>
>> dbpmn[4]<-
>>  ifelse(as.character(dbpmn[,1]) == as.character(dbpmn[,(2)]),
>>  as.character(dbpmn[,3]),"")
>> dbpmn
>>    V1 V2 V3 V4
>> 1   B  D  C
>> 2   C  A  D
>> 3   C  B  A
>> 4   A  B  C
>> 5   B  D  B
>> 6   D  D  A  A
>> 7   D  D  D  D
>> 8   B  C  A
>> 9   B  D  B
>> 10  D  C  A
>> 11  A  D  C
>> 12  A  C  B
>> 13  A  A  A  A
>> 14  D  C  A
>> 15  C  D  B
>> 16  A  A  B  B
>> 17  A  C  C
>> 18  B  B  C  C
>> 19  C  C  C  C
>> 20  D  D  D  D
>>
>> Jim
>>
>
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