[R] How to dynamically add variables to a dataframe

[peter dalgaard]

Like this?

> V <- c("fee","fie","foe")
> aq <- head(airquality) # Just to get a shorter example
> aq[V] <- 0
> aq
  Ozone Solar.R Wind Temp Month Day fee fie foe
1    41     190  7.4   67     5   1   0   0   0
2    36     118  8.0   72     5   2   0   0   0
3    12     149 12.6   74     5   3   0   0   0
4    18     313 11.5   62     5   4   0   0   0
5    NA      NA 14.3   56     5   5   0   0   0
6    28      NA 14.9   66     5   6   0   0   0


> On 22 Apr 2018, at 10:13 , Luca Meyer <lucam1968 using gmail.com> wrote:
> 
> Hi,
> 
> I am a bit rusty with R programming and do not seem to find a solution to
> add a number of variables to my existing dataframe. Basically I need to add
> n=dim(d1)[1] variables to my d0 dataframe and I would like them to be named
> V1, V2, V3, ... , V[dim(d1)[1])
> 
> When running the following code:
> 
> for (t in 1:dim(d1)[1]){
>  d0$V[t] <- 0
> }
> 
> all I get is a V variable populated with zeros...
> 
> I am sure there is a fairly straightforward code to accomplish what I need,
> any suggestion?
> 
> Thank you,
> 
> Luca
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
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