[R] (newbie) sum for certain number of rows

[kelvin lau]

I have following data in a data.csv file separated by space

0 0 1 0 0 1 0 1
0 0 0 0 0 0 0 0
1 0 0 1 1 0 1 0
0 0 1 1 0 0 0 0
1 1 0 0 0 0 1 1
0 0 0 0 0 0 0 0
0 1 0 1 1 0 1 0
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
etc...

I wish to calculate the sum of each column for certain number of rows. For 
example if I want sum of the data after each 3 rows, it should display
1 0 1 1 1 1 1 1
1 1 1 1 0 0 1 1
2 3 2 3 3 2 3 2

So far, this is what I have done
xx-read.table(data.csv,header=FALSE)
ss-t(apply(xx,2,sum)) # which displayed the sum of all rows

I tried my best to look for solution on the Internet but so far haven't managed 
to find it. I am extremely grateful if someone can point me how to go about it. 
Thanks.

Kelvin

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Re: [R] (newbie) sum for certain number of rows

[kelvin lau]

Thanks. I tried it and it worked wonderful.


Wishing for the DAY' to come. Life needs to be 'reset'.


--- On Wed, 7/15/09, Dimitris Rizopoulos d.rizopou...@erasmusmc.nl wrote:

 From: Dimitris Rizopoulos d.rizopou...@erasmusmc.nl
 Subject: Re: [R] (newbie) sum for certain number of rows
 To: kelvin lau kelvin...@yahoo.com
 Cc: r-help@r-project.org
 Date: Wednesday, July 15, 2009, 6:25 PM
 one way is the following:
 
 dat - read.table(textConnection(
 0 0 1 0 0 1 0 1
 0 0 0 0 0 0 0 0
 1 0 0 1 1 0 1 0
 0 0 1 1 0 0 0 0
 1 1 0 0 0 0 1 1
 0 0 0 0 0 0 0 0
 0 1 0 1 1 0 1 0
 1 1 1 1 1 1 1 1
 1 1 1 1 1 1 1 1
 ))
 closeAllConnections()
 
 k - 3
 ind - rep(seq(1, nrow(dat)/k), each = k)
 rowsum(dat, ind)
 
 
 I hope it helps.
 
 Best,
 Dimitris
 
 
 kelvin lau wrote:
  I have following data in a data.csv file separated by
 space
  
  0 0 1 0 0 1 0 1
  0 0 0 0 0 0 0 0
  1 0 0 1 1 0 1 0
  0 0 1 1 0 0 0 0
  1 1 0 0 0 0 1 1
  0 0 0 0 0 0 0 0
  0 1 0 1 1 0 1 0
  1 1 1 1 1 1 1 1
  1 1 1 1 1 1 1 1
  etc...
  
  I wish to calculate the sum of each column for certain
 number of rows. For example if I want sum of the data after
 each 3 rows, it should display
  1 0 1 1 1 1 1 1
  1 1 1 1 0 0 1 1
  2 3 2 3 3 2 3 2
  
  So far, this is what I have done
  xx-read.table(data.csv,header=FALSE)
  ss-t(apply(xx,2,sum)) # which displayed the sum of
 all rows
  
  I tried my best to look for solution on the Internet
 but so far haven't managed to find it. I am extremely
 grateful if someone can point me how to go about it.
 Thanks.
  
  Kelvin
  
  __
  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.
  
 
 -- Dimitris Rizopoulos
 Assistant Professor
 Department of Biostatistics
 Erasmus University Medical Center
 
 Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
 Tel: +31/(0)10/7043478
 Fax: +31/(0)10/7043014


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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.