Dear useRs!
I would like to list all possible samples of size n form a population of
size N. Obviously, N must be small (up to 20??) for this to be possible.
For example, let say that N = 3 and n = 2. Therefore, we can say we have
units 1, 2 and 3. I believe all possible samples are : {1,2},{2,3} and
{1,3}.
I would like to emphasize that I am not looking for the number of different
samples, but a list of all possible samples.
Thank you in advance for any suggestions.
Best,
Ales Ziberna
Listing all possible samples of size n form a population of size N
3 messages · (Ted Harding), Ales Ziberna
On 08-Dec-05 Ales Ziberna wrote:
Dear useRs!
I would like to list all possible samples of size n form a
population of size N. Obviously, N must be small (up to 20??)
for this to be possible.
For example, let say that N = 3 and n = 2. Therefore, we can
say we have units 1, 2 and 3. I believe all possible samples
are : {1,2},{2,3} and {1,3}.
I would like to emphasize that I am not looking for the number
of different samples, but a list of all possible samples.
Install package "combinat" and use the function 'combn' therein:
library(combinat) ?combn
combn((1:3),2)
[,1] [,2] [,3] [1,] 1 1 2 [2,] 2 3 3
combn((1:5),2)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 1 1 1 1 2 2 2 3 3 4 [2,] 2 3 4 5 3 4 5 4 5 5
combn((1:5),3)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 1 1 1 1 1 1 2 2 2 3 [2,] 2 2 2 3 3 4 3 3 4 4 [3,] 3 4 5 4 5 5 4 5 5 5 and so on ... Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 08-Dec-05 Time: 15:07:37 ------------------------------ XFMail ------------------------------
I would like to thank Ted Harding and Kristel Joossens for their replies! They both work perferctly. I would also like to appologize for not finding the package combinat myself! Thank you aggain, Ales Ziberna ----- Original Message ----- From: "Ted Harding" <Ted.Harding at nessie.mcc.ac.uk> To: "Ales Ziberna" <aleszib at gmail.com> Cc: "R-help" <r-help at stat.math.ethz.ch> Sent: Thursday, December 08, 2005 4:07 PM Subject: RE: [R] Listing all possible samples of size n form a population
On 08-Dec-05 Ales Ziberna wrote:
Dear useRs!
I would like to list all possible samples of size n form a
population of size N. Obviously, N must be small (up to 20??)
for this to be possible.
For example, let say that N = 3 and n = 2. Therefore, we can
say we have units 1, 2 and 3. I believe all possible samples
are : {1,2},{2,3} and {1,3}.
I would like to emphasize that I am not looking for the number
of different samples, but a list of all possible samples.
Install package "combinat" and use the function 'combn' therein:
library(combinat) ?combn
combn((1:3),2)
[,1] [,2] [,3] [1,] 1 1 2 [2,] 2 3 3
combn((1:5),2)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 1 1 1 1 2 2 2 3 3 4 [2,] 2 3 4 5 3 4 5 4 5 5
combn((1:5),3)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] 1 1 1 1 1 1 2 2 2 3 [2,] 2 2 2 3 3 4 3 3 4 4 [3,] 3 4 5 4 5 5 4 5 5 5 and so on ... Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <Ted.Harding at nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 08-Dec-05 Time: 15:07:37 ------------------------------ XFMail ------------------------------