perm.paired.loc {wPerm} | R Documentation |
Paired-Sample Permutation Test for Difference in Location
Description
Performs a permutation (randomization) test for difference in location based on a paired sample.
Usage
perm.paired.loc(x, y, parameter, variable = NULL,
alternative = c("two.sided", "less", "greater"),
R = 9999)
Arguments
x |
a numeric vector of data values representing the first components of the pairs. |
y |
a numeric vector of data values representing the second components of the pairs. |
parameter |
the location parameter under consideration (e.g., mean, trimmed mean). |
variable |
an optional character string that gives the name of the variable under consideration. |
alternative |
a character string specifying the alternative hypothesis; must be one of "two.sided" (default), "less", or "greater". |
R |
number of replications (default = 9999). |
Details
The null hypothesis is that the distributions of the variable on the two populations are identical—"identical".
The possible alternative hypotheses are:
Two tailed ("two.sided"): The distribution of the variable on the first population has either systematically smaller values or systematically larger values than that of the variable on the second population—"shifted".
Left tailed ("less"): The distribution of the variable on the first population has systematically smaller values than that of the variable on the second population—"shifted.left".
Right tailed ("greater"): The distribution of the variable on the first population has systematically larger values than that of the variable on the second population—"shifted.right".
Value
A list with class "perm.paired.loc" containing the following components:
Perm.values |
the values of the test statistic obtained from the permutations. |
Header |
the main title for the output. |
Variable |
the name of the variable under consideration or NULL. |
Pop.1 |
the first population. |
Pop.2 |
the second population. |
n |
the sample size. |
Statistic |
the test statistic. |
Observed |
the observed value of the test statistic. |
Null |
the null hypothesis; here, always identical. |
Alternative |
the alternative hypothesis. |
P.value |
the P-value or a statement like P < 0.001. |
p.value |
the P-value. |
Author(s)
Neil A. Weiss
Examples
# Ages of a sample of 10 heterosexual spouses.
data("spouse.ages")
str(spouse.ages)
attach(spouse.ages)
# Paired-sample permutation test to decide whether there is a difference
# in location for age distributions of married men and married women,
# using the mean as the location parameter. Variable named "Age".
perm.paired.loc(HUSBAND, WIFE, mean, "Age")
# Paired-sample permutation test to decide whether married men have
# systematically greater ages than married women, using the 10% trimmed
# mean as the location parameter.
tr10.mean <- function(x) mean(x, trim = 0.10)
perm.paired.loc(HUSBAND, WIFE, tr10.mean, alternative = "greater")
detach(spouse.ages) # clean up.