I wonder how to call for five-number stats from describeBy() function as provided by summary(). After calling library(psych), the current function reports min, max and median, but not stats for 25th and 75th quartiles.
attach(mtcars)
describeBy(mpg, gear)
var n mean sd median trimmed mad min max range skew kurtosis se
Appreciate your help in advance.
There is also a built-in base function specifically for the five numbers unsurprisingly called: fivenum
aggregate(mpg ~ gear, data=mtcars, fivenum)
gear mpg.1 mpg.2 mpg.3 mpg.4 mpg.5
1 3 10.40 14.50 15.50 18.40 21.50
2 4 17.80 21.00 22.80 28.85 33.90
3 5 15.00 15.80 19.70 26.00 30.40
EDIT
to answer the followup Q in comments (as I interpret it) you can use the . in the formula to specify all other columns
aggregate(.~gear, data=mtcars, fivenum)
#too wide to print here
Or if you just want the fivenum for all columns without the gear split then that is:
apply(mtcars, 2,fivenum)
mpg cyl disp hp drat wt qsec vs am gear carb
[1,] 10.40 4 71.10 52 2.760 1.5130 14.500 0 0 3 1
[2,] 15.35 4 120.65 96 3.080 2.5425 16.885 0 0 3 2
[3,] 19.20 6 196.30 123 3.695 3.3250 17.710 0 0 4 2
[4,] 22.80 8 334.00 180 3.920 3.6500 18.900 1 1 4 4
[5,] 33.90 8 472.00 335 4.930 5.4240 22.900 1 1 5 8