Symbol | Names | Definition |
Q1 | first quartile lower quartile 25th percentile | splits off the lowest 25% of data from the highest 75% 일사분위수 (하한사분위수) |
Q2 | second quartile median 50th percentile | cuts data set in half (중앙값) |
Q3 | third quartile upper quartile 75th percentile | splits off the highest 25% of data from the lowest 75% 삼사분위수 (상한사분위수) |
interquartile and outliers
사분범위 = Q3 - Q1
사분범위 = (상한사분위수) - (하한사분위수)
> k <- c(1:8) > k [1] 1 2 3 4 5 6 7 8 > quantile(k) 0% 25% 50% 75% 100% 1.00 2.75 4.50 6.25 8.00 >
{1, 2, 3, 4, 5, 6, 7, 8}
head first
위의 방법으로는
lower quartile: 2.5
upper quartile: 6.5
Ordered Data Set: 6, 7, 15, 36, 39, 40, 41, 42, 43, 47, 49
in r
j <- c(1,2,3,4,5) j <- sort(j) quantile(j)
> j <- c(1,2,3,4,5) > j <- sort(j) > quantile(j) 0% 25% 50% 75% 100% 1 2 3 4 5 >
Odd number of elements
j2 <- c(1,2,3,4,5,6) j2 <- sort(j2) quantile(j2)
> j2 <- c(1,2,3,4,5,6) > j2 <- sort(j2) > quantile(j2) 0% 25% 50% 75% 100% 1.00 2.25 3.50 4.75 6.00 > >
Even number of elements
> j3 <- c(7, 18, 5, 9, 12, 15) > j3s <- sort(j3) > j3s [1] 5 7 9 12 15 18 > quantile(j3s) 0% 25% 50% 75% 100% 5.00 7.50 10.50 14.25 18.00 >
median = (9+12)/2
the 1st quartile = 7 + 1) = 7 + 0.5 = 7.5
the 3rd quartile = 12 + 2) = 12 + 2.25 = 14.25
in r
> duration = faithful$eruptions # the eruption duration > quantile(duration) # apply the quantile function 0% 25% 50% 75% 100% 1.6000 2.1627 4.0000 4.4543 5.1000
quantile, not qurtile