jmv

Paired Samples T-Test

Provides a range of descriptive statistics

Example usage

data('bugs', package = 'jmv')

ttestPS(bugs, pairs = list(
        list(i1 = 'LDLF', i2 = 'LDHF')))

#
#  Paired Samples T-Test
#  ──────────────────────────────────────────────────────────────
#                                   statistic    df      p
#  ──────────────────────────────────────────────────────────────
#    LDLF    LDHF    Student's t        -6.65    90.0    < .001
#  ──────────────────────────────────────────────────────────────
#

Arguments

data the data as a data frame
pairs a list of lists specifying the pairs of measurement in data
students TRUE (default) or FALSE, perform Student's t-tests
bf TRUE or FALSE (default), provide Bayes factors
bfPrior a number between 0.5 and 2 (default 0.707), the prior width to use in calculating Bayes factors
wilcoxon TRUE or FALSE (default), perform Wilcoxon signed rank tests
hypothesis 'different' (default), 'oneGreater' or 'twoGreater', the alternative hypothesis; group 1 different to group 2, group 1 greater than group 2, and group 2 greater than group 1 respectively
norm TRUE or FALSE (default), perform Shapiro-wilk normality tests
meanDiff TRUE or FALSE (default), provide means and standard errors
effectSize TRUE or FALSE (default), provide effect sizes
ci TRUE or FALSE (default), provide confidence intervals
ciWidth a number between 50 and 99.9 (default: 95), the width of confidence intervals
desc TRUE or FALSE (default), provide descriptive statistics
plots TRUE or FALSE (default), provide descriptive plots
miss 'perAnalysis' or 'listwise', how to handle missing values; 'perAnalysis' excludes missing values for individual dependent variables, 'listwise' excludes a row from all analyses if one of its entries is missing.

Returns

A results object containing:

results$ttest a table
results$norm a table
results$desc a table
results$plots an array of images

Tables can be converted to data frames with asDF or as.data.frame(). For example:

results$ttest$asDF

as.data.frame(results$ttest)

Elements in arrays can be accessed with [[n]]. For example:

results$plots[[1]] # accesses the first element