Example 3 - Manual data

data()

data(package = .packages(all.available = TRUE))

mydata <- force(USArrests)

library(psych)

## Warning: package 'psych' was built under R version 4.3.3

mydata <- force(sat.act)

I would like to show first 6 rows of my dataset

head(mydata)

##       gender education age ACT SATV SATQ
## 29442      2         3  19  24  500  500
## 29457      2         3  23  35  600  500
## 29498      2         3  20  21  480  470
## 29503      1         4  27  26  550  520
## 29504      1         2  33  31  600  550
## 29518      1         5  26  28  640  640

mydata$genderF <- factor(mydata$gender,
                         levels = c(1, 2),
                         labels = c("M", "F"))

library(psych)
describeBy(mydata$ACT, mydata$genderF)

## 
##  Descriptive statistics by group 
## group: M
##    vars   n  mean   sd median trimmed  mad min max range  skew kurtosis   se
## X1    1 247 28.79 5.06     30   29.23 4.45   3  36    33 -1.06     1.89 0.32
## ------------------------------------------------------------ 
## group: F
##    vars   n  mean   sd median trimmed  mad min max range  skew kurtosis   se
## X1    1 453 28.42 4.69     29   28.63 4.45  15  36    21 -0.39    -0.42 0.22