| spv {trotter} | R Documentation |
Selections Pseudo-Vector Constructor
Description
The SPV class defines a pseudo-vector containing all
the arranged k-selections (combinations with replacement) of the objects stored
in items. The function spv is a constructor for this class.
Usage
spv(k, items)
Arguments
k |
the number of objects taken at a time. |
items |
a vector of objects to be selected. |
Details
The selections are arranged according to the order in which the objects
appear in items. The arrangement is very similar to the arrangement
of combinations (see cpv) except that objects may be repeatedly selected.
Value
an instance of SPV.
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
Combinations Pseudo-Vector cpv
Amalgams Pseudo-Vector apv
Subsets Pseudo-Vector sspv
Examples
# create a pseudo-vector of 10-selections from the first 15 letters
s <- spv(10, letters[1:15])
# generate a description
print(s)
# compatable with length
length(s)
# inspect a few of the combinations "stored" in s
s[1]
s[1000]
s[1961256]