jmv (version 2.0)

descriptives: Descriptives

Description

Descriptives are an assortment of summarising statistics, and visualizations which allow exploring the shape and distribution of data. It is good practice to explore your data with descriptives before proceeding to more formal tests.

Usage

descriptives(data, vars, splitBy = NULL, freq = FALSE,
  desc = "columns", hist = FALSE, dens = FALSE, bar = FALSE,
  barCounts = FALSE, box = FALSE, violin = FALSE, dot = FALSE,
  dotType = "jitter", boxMean = FALSE, qq = FALSE, n = TRUE,
  missing = TRUE, mean = TRUE, median = TRUE, mode = FALSE,
  sum = FALSE, sd = TRUE, variance = FALSE, range = FALSE,
  min = TRUE, max = TRUE, se = FALSE, ci = FALSE, ciWidth = 95,
  iqr = FALSE, skew = FALSE, kurt = FALSE, sw = FALSE,
  pcEqGr = FALSE, pcNEqGr = 4, pc = FALSE, pcValues = "25,50,75",
  formula)

Arguments

data

the data as a data frame

vars

a vector of strings naming the variables of interest in data

splitBy

a vector of strings naming the variables used to split vars

freq

TRUE or FALSE (default), provide frequency tables (nominal, ordinal variables only)

desc

'rows' or 'columns' (default), display the variables across the rows or across the columns (default)

hist

TRUE or FALSE (default), provide histograms (continuous variables only)

dens

TRUE or FALSE (default), provide density plots (continuous variables only)

bar

TRUE or FALSE (default), provide bar plots (nominal, ordinal variables only)

barCounts

TRUE or FALSE (default), add counts to the bar plots

box

TRUE or FALSE (default), provide box plots (continuous variables only)

violin

TRUE or FALSE (default), provide violin plots (continuous variables only)

dot

TRUE or FALSE (default), provide dot plots (continuous variables only)

dotType

.

boxMean

TRUE or FALSE (default), add mean to box plot

qq

TRUE or FALSE (default), provide Q-Q plots (continuous variables only)

n

TRUE (default) or FALSE, provide the sample size

missing

TRUE (default) or FALSE, provide the number of missing values

mean

TRUE (default) or FALSE, provide the mean

median

TRUE (default) or FALSE, provide the median

mode

TRUE or FALSE (default), provide the mode

sum

TRUE or FALSE (default), provide the sum

sd

TRUE (default) or FALSE, provide the standard deviation

variance

TRUE or FALSE (default), provide the variance

range

TRUE or FALSE (default), provide the range

min

TRUE or FALSE (default), provide the minimum

max

TRUE or FALSE (default), provide the maximum

se

TRUE or FALSE (default), provide the standard error

ci

TRUE or FALSE (default), provide confidence intervals for the mean

ciWidth

a number between 50 and 99.9 (default: 95), the width of confidence intervals

iqr

TRUE or FALSE (default), provide the interquartile range

skew

TRUE or FALSE (default), provide the skewness

kurt

TRUE or FALSE (default), provide the kurtosis

sw

TRUE or FALSE (default), provide Shapiro-Wilk p-value

pcEqGr

TRUE or FALSE (default), provide quantiles

pcNEqGr

an integer (default: 4) specifying the number of equal groups

pc

TRUE or FALSE (default), provide percentiles

pcValues

a comma-sepated list (default: 25,50,75) specifying the percentiles

formula

(optional) the formula to use, see the examples

Value

A results object containing:

results$descriptives					a table of the descriptive statistics
results$descriptivesT					a table of the descriptive statistics
results$frequencies					an array of frequency tables
results$plots					an array of descriptive plots

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

results$descriptives$asDF

as.data.frame(results$descriptives)

Examples

# NOT RUN {
data('mtcars')
dat <- mtcars

# frequency tables can be provided for factors
dat$gear <- as.factor(dat$gear)

descriptives(dat, vars = vars(mpg, cyl, disp, gear), freq = TRUE)

#
#  DESCRIPTIVES
#
#  Descriptives
#  -------------------------------------------
#               mpg     cyl     disp    gear
#  -------------------------------------------
#    N            32      32      32      32
#    Missing       0       0       0       0
#    Mean       20.1    6.19     231    3.69
#    Median     19.2    6.00     196    4.00
#    Minimum    10.4    4.00    71.1       3
#    Maximum    33.9    8.00     472       5
#  -------------------------------------------
#
#
#  FREQUENCIES
#
#  Frequencies of gear
#  --------------------
#    Levels    Counts
#  --------------------
#    3             15
#    4             12
#    5              5
#  --------------------
#

# spliting by a variable
descriptives(formula = disp + mpg ~ cyl, dat,
    median=F, min=F, max=F, n=F, missing=F)

# providing histograms
descriptives(formula = mpg ~ cyl, dat, hist=T,
    median=F, min=F, max=F, n=F, missing=F)

# splitting by multiple variables
descriptives(formula = mpg ~ cyl:gear, dat,
    median=F, min=F, max=F, missing=F)
# }