cpv {trotter} | R Documentation |
Combinations Pseudo-Vector Constructor
Description
The CPV
class defines a pseudo-vector containing all
the arranged k
-combinations of the objects stored
in items
. The function cpv
is a constructor for this class.
Usage
cpv(k, items)
Arguments
k |
the number of objects taken at a time. |
items |
a vector of objects to be combined. |
Details
The combinations are arranged according to the order in which the objects
appear in items
. Combinations containing the first object in
items
are followed by combinations that contain the second object
but not the first, which are followed by combinations that contain the third
but neither the first or the second, etc.
Value
an instance of CPV
.
Author(s)
Richard Ambler
References
Steinhaus-Johnson-Trotter algorithm. (2014, April 29). In Wikipedia, The Free Encyclopedia. Retrieved 13:24, September 5, 2014
See Also
Permutations Pseudo-Vector ppv
Amalgams Pseudo-Vector apv
Selections Pseudo-Vector spv
Subsets Pseudo-Vector sspv
Examples
# create a pseudo-vector of 10-combinations from the first 15 letters
c <- cpv(10, letters[1:15])
# generate a description
print(c)
# compatable with length
length(c)
# inspect a few of the combinations "stored" in c
c[1]
c[1000]
c[3003]