Computes descriptive statistics by groups for a measure variable.
desc_statby(data, measure.var, grps, ci = 0.95)a data frame.
the name of a column containing the variable to be summarized.
a character vector containing grouping variables; e.g.: grps = c("grp1", "grp2")
the percent range of the confidence interval (default is 0.95).
A data frame containing descriptive statistics, such as:
length: the number of elements in each group
min: minimum
max: maximum
median: median
mean: mean
iqr: interquartile range
mad: median absolute deviation (see ?MAD)
sd: standard deviation of the sample
se: standard error of the mean. It's calculated as the sample standard deviation divided by the root of the sample size.
ci: confidence interval of the mean
range: the range = max - min
cv: coefficient of variation, sd/mean
var: variance, sd^2
# Load data
data("ToothGrowth")
# Descriptive statistics
res <- desc_statby(ToothGrowth, measure.var = "len",
grps = c("dose", "supp"))
head(res[, 1:10])
#> dose supp length min max median mean iqr mad sd
#> 1 0.5 OJ 10 8.2 21.5 12.25 13.23 6.475 4.29954 4.459709
#> 2 0.5 VC 10 4.2 11.5 7.15 7.98 4.950 3.55824 2.746634
#> 3 1.0 OJ 10 14.5 27.3 23.45 22.70 5.350 3.92889 3.910953
#> 4 1.0 VC 10 13.6 22.5 16.50 16.77 2.025 1.70499 2.515309
#> 5 2.0 OJ 10 22.4 30.9 25.95 26.06 2.500 2.07564 2.655058
#> 6 2.0 VC 10 18.5 33.9 25.95 26.14 5.425 4.59606 4.797731