R help - Jun 2011 - Help in a project

To whom it may concern,
I am a new user to R and I need help in my if and for statements as I need a
place marker.

I would like to convert the following table:
Observation | Variable 1
--------------------|-------------
1 | 10000
2 | A 
3 | 631 

Into :
Observation| Variable 1 | Variable 1 Flag
----------------|------------------|------------------
1 |  10000 | NA
2 | NA | A
3 | 631 | NA


please note |  represents another column.

this is for a large data set and I cannot manually go through this:
my attempt to this was :
l=0 # placeholder
m<-c() #newvariable 1
v<-c() #newvariable flag
for (z in tablename1$Variable_1)
(if (is.numeric(z) ) m[z:l] l=l+1 else v[z:1] l=l+1

Can you please guide me as to how to approach this problem?
Any help would be greatly appreciated.
Tarun Manchanda


	[[alternative HTML version deleted]]

Hello,

three commands might do the job (NOTE: df=your data frame, 
obser=Observation, var1=Variable 1 [TYPE: string], var1flag=Variable 1 
flag [TYPE: string])

1. df$var1flag<-NA
2. df$var1flag[ is.na(as.numeric(df$var1)) ]<-df$var1[ 
is.na(as.numeric(df$var1)) ]
3. df$var1<-as.numeric(df$var1)

{Please note: Var1 must be type string at the beginning. Otherwise this 
would not work (you cannot have an "A" in a numeric column...)]

After this, 'df' gives:

 > df
   obser var1 var1flag
1     1 1000     <NA>
2     2 <NA>        A
3     3  631     <NA>

Is this what You are looking for?

HTH,
Kimmo

02.06.2011 18:28, Tarun Manchanda wrote:
> To whom it may concern,
> I am a new user to R and I need help in my if and for statements as I need
a place marker.
>
> I would like to convert the following table:
> Observation | Variable 1
> --------------------|-------------
> 1 | 10000
> 2 | A
> 3 | 631
>
> Into :
> Observation| Variable 1 | Variable 1 Flag
> ----------------|------------------|------------------
> 1 |  10000 | NA
> 2 | NA | A
> 3 | 631 | NA
>
>
> please note |  represents another column.