R help - May 2010 - Adding a row at top of dataframe

I have a large data frame 48:2185 with different numbers.
I would like to add only one row at the very top of my data frame with  
0's or NA's.
I don't know which approach to use. Should i create 2 different data  
frames and merge them? Ive also tried the rbind command with no luck.  
I would appreciate some help to achieve what I'm trying to create.
Thanks!

Try this:
> x <- data.frame(a=1:10, b=1:10)
> x
    a  b
1   1  1
2   2  2
3   3  3
4   4  4
5   5  5
6   6  6
7   7  7
8   8  8
9   9  9
10 10 10
> # add a row at the top
> x <- x[c(1,seq(nrow(x))),]
> x
     a  b
1    1  1
1.1  1  1
2    2  2
3    3  3
4    4  4
5    5  5
6    6  6
7    7  7
8    8  8
9    9  9
10  10 10
>
> # fill in with the values you want.
> x[1,] <- NA
On Mon, May 17, 2010 at 11:28 AM, <ecvetano@uwaterloo.ca> wrote:
> I have a large data frame 48:2185 with different numbers.
> I would like to add only one row at the very top of my data frame with
0's
> or NA's.
> I don't know which approach to use. Should i create 2 different data
frames
> and merge them? Ive also tried the rbind command with no luck. I would
> appreciate some help to achieve what I'm trying to create.
> Thanks!
>
> ______________________________________________
> 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<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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Does this work?

data(cars)
cars2 <- cars
cars2[2:nrow(cars)+1,] <- cars2[1:nrow(cars),]
cars2[1,] <- NA



Nikhil Kaza
Asst. Professor,
City and Regional Planning
University of North Carolina

nikhil.list at gmail.com



On May 17, 2010, at 11:28 AM, ecvetano at uwaterloo.ca wrote:
> I have a large data frame 48:2185 with different numbers.
> I would like to add only one row at the very top of my data frame  
> with 0's or NA's.
> I don't know which approach to use. Should i create 2 different data  
> frames and merge them? Ive also tried the rbind command with no  
> luck. I would appreciate some help to achieve what I'm trying to  
> create.
> Thanks!
>
> ______________________________________________
> 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.

On 2010-05-17 9:28, ecvetano at uwaterloo.ca wrote:
> I have a large data frame 48:2185 with different numbers.
> I would like to add only one row at the very top of my data frame with
> 0's or NA's.
> I don't know which approach to use. Should i create 2 different data
> frames and merge them? Ive also tried the rbind command with no luck. I
> would appreciate some help to achieve what I'm trying to create.
> Thanks!
Say your dataframe is named 'dat'.

  x <- rep(NA, ncol(dat))
  dat <- rbind(x, dat)

will insert a row of NA's.

  x <- rep(0, ncol(dat))
  dat <- rbind(x, dat)

will insert a row of 0s. If any of your variables are not
numeric or character, you'll get a warning.

  -Peter Ehlers

My mistake.

cars2 should be initalized to have all the extra rows.

cars2 <- data.frame(matrix(rep(NA, prod(dim(cars)) + ncol(cars)),  
nrow(cars)+1))
cars2[2:nrow(cars2),] <- cars

In this way, insertion at any row is possible.

Nikhil

On May 17, 2010, at 2:46 PM, Peter Ehlers wrote:
>>>> data(cars)
>>>> cars2 <- cars
>>>> cars2[2:nrow(cars)+1,] <- cars2[1:nrow(cars),]
>>>> cars2[1,] <- NA

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