下面代碼在R工作空間做平均值哼审，中位數(shù)，四分位數(shù)孕豹，標(biāo)準(zhǔn)差涩盾，標(biāo)準(zhǔn)分的簡(jiǎn)單實(shí)踐計(jì)算。
案例1
#從10——20里面隨機(jī)選取5個(gè)數(shù)
> x <- runif(5,10,20)
> x
[1] 17.35065 15.03454 14.87279 17.62638 16.58668
#求平均值
> mean(x)
[1] 16.29421
#求中位數(shù)
> median(x)
[1] 16.58668
#求四分位數(shù)
> quantile(x)
0%? ? ? 25%? ? ? 50%? ? ? 75%? ? 100%
14.87279 15.03454 16.58668 17.35065 17.62638
#求標(biāo)準(zhǔn)差
> sd(x)
[1] 1.282915
#求標(biāo)準(zhǔn)分
> (17.35065-mean(x))/sd(x)
[1] 0.8234702
案例2
> #R自帶的空氣質(zhì)量數(shù)據(jù)集 str 結(jié)構(gòu)structure的縮寫
> str(airquality)
'data.frame':? 153 obs. of? 6 variables:
$ Ozone? : int? 41 36 12 18 NA 28 23 19 8 NA ...
$ Solar.R: int? 190 118 149 313 NA NA 299 99 19 194 ...
$ Wind? : num? 7.4 8 12.6 11.5 14.3 14.9 8.6 13.8 20.1 8.6 ...
$ Temp? : int? 67 72 74 62 56 66 65 59 61 69 ...
$ Month? : int? 5 5 5 5 5 5 5 5 5 5 ...
$ Day? ? : int? 1 2 3 4 5 6 7 8 9 10 ...
> #匯總數(shù)據(jù)包括 最小值励背、分位數(shù)旁赊、平均數(shù)、中位數(shù)椅野、最大值终畅、缺失值(NA's)
> summary(airquality)
Ozone? ? ? ? ? Solar.R? ? ? ? ? Wind? ? ? ? ? ? Temp
Min.? :? 1.00? Min.? :? 7.0? Min.? : 1.700? Min.? :56.00
1st Qu.: 18.00? 1st Qu.:115.8? 1st Qu.: 7.400? 1st Qu.:72.00
Median : 31.50? Median :205.0? Median : 9.700? Median :79.00
Mean? : 42.13? Mean? :185.9? Mean? : 9.958? Mean? :77.88
3rd Qu.: 63.25? 3rd Qu.:258.8? 3rd Qu.:11.500? 3rd Qu.:85.00
Max.? :168.00? Max.? :334.0? Max.? :20.700? Max.? :97.00
NA's? :37? ? ? NA's? :7
Month? ? ? ? ? ? Day
Min.? :5.000? Min.? : 1.0
1st Qu.:6.000? 1st Qu.: 8.0
Median :7.000? Median :16.0
Mean? :6.993? Mean? :15.8
3rd Qu.:8.000? 3rd Qu.:23.0
Max.? :9.000? Max.? :31.0
> #選取數(shù)據(jù)集airquality中的Ozone變量籍胯，匯總Ozone中的最小值、分位數(shù)离福、平均數(shù)杖狼、中位數(shù)、最大值妖爷、缺失值（NA's）
> summary(airquality$Ozone)
Min. 1st Qu.? Median? ? Mean 3rd Qu.? ? Max.? ? NA's
1.00? 18.00? 31.50? 42.13? 63.25? 168.00? ? ? 37
> #分位數(shù)
> quantile(airquality$Ozone, na.rm = T)#na.rm=T 對(duì)缺失值進(jìn)行刪除蝶涩，存在缺失值，結(jié)果為NA
0%? ? 25%? ? 50%? ? 75%? 100%
1.00? 18.00? 31.50? 63.25 168.00
> #平均值
> X <- mean(airquality$Ozone, na.rm = T)
> X
[1] 42.12931
> #中位數(shù)
> median(airquality$Ozone, na.rm = T)
[1] 31.5
> #標(biāo)準(zhǔn)差
> Y <- sd(airquality$Ozone, na.rm = T)
> #標(biāo)準(zhǔn)分,計(jì)算28在Ozone變量中的相對(duì)排名
> Z <- (28-X)/Y
> Z
[1] -0.4283182
