infer_ts_var_test {inferr} | R Documentation |
Two Sample Variance Comparison Test
Description
infer_ts_var_test
performs tests on the equality of standard
deviations (variances).
Usage
infer_ts_var_test(
data,
...,
group_var = NULL,
alternative = c("less", "greater", "all")
)
Arguments
data |
a |
... |
numeric; column(s) in |
group_var |
factor; column in |
alternative |
a character string specifying the alternative hypothesis, must be one of "both" (default), "greater", "less" or "all". You can specify just the initial letter. |
Value
infer_ts_var_test
returns an object of class "infer_ts_var_test"
.
An object of class "infer_ts_var_test"
is a list containing the
following components:
f |
f statistic |
lower |
lower one-sided p-value |
upper |
upper one-sided p-value |
two_tail |
two-sided p-value |
vars |
variances for each level of the grouping variable |
avgs |
means for each level of the grouping variable |
sds |
standard deviations for each level of the grouping variable |
ses |
standard errors for each level of the grouping variable |
avg |
combined mean |
sd |
combined standard deviation |
se |
estimated combined standard error |
n1 |
numerator degrees of freedom |
n2 |
denominator degrees of freedom |
lens |
number of observations for each level of grouping variable |
len |
number of observations |
lev |
levels of the grouping variable |
type |
alternative hypothesis |
Deprecated Function
var_test()
has been deprecated. Instead use infer_ts_var_test()
.
References
Sheskin, D. J. 2007. Handbook of Parametric and Nonparametric Statistical Procedures, 4th edition. : Chapman & Hall/CRC.
See Also
Examples
# using grouping variable
infer_ts_var_test(hsb, read, group_var = female, alternative = 'less')
# using two variables
infer_ts_var_test(hsb, read, write, alternative = 'less')