2020-04-13-Homework-3

讀取檔案

library(MASS)
dta <- MASS::nlschools[,-c(1,5,6)]
unique(dta$GS)

##  [1] 29 19 25 31 35 28 21 32 22 14 16 11 18 15 27 26 30 23 17 24 34 33 20 39 36
## [26] 10 37 13

挑選五個人數超過三十的班級，合併

dta.1 <- subset(dta, dta$class == 1280)
dta.2 <- subset(dta, dta$class == 3880)
dta.3 <- subset(dta, dta$class == 5780)
dta.4 <- subset(dta, dta$class == 10780)
dta.5 <- subset(dta, dta$class == 11580)
dat <- rbind(dta.5,rbind(dta.4,rbind(dta.3,rbind(dta.1, dta.2))))

先將class轉換成character，再切割

dat$class <- as.character(dat$class)
dat.2 <- split(dat, dat$class)

繪圖

par(mfrow=c(3, 3), mar = c(2, 1, 1, 1))
lapply(dat.2, function(x) {hist(x$IQ, xlab="IQ", breaks =  seq(6,18,1))})

## $`10780`
## $breaks
##  [1]  6  7  8  9 10 11 12 13 14 15 16 17 18
## 
## $counts
##  [1] 0 0 0 0 4 2 3 3 3 1 1 0
## 
## $density
##  [1] 0.00000000 0.00000000 0.00000000 0.00000000 0.23529412 0.11764706
##  [7] 0.17647059 0.17647059 0.17647059 0.05882353 0.05882353 0.00000000
## 
## $mids
##  [1]  6.5  7.5  8.5  9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5
## 
## $xname
## [1] "x$IQ"
## 
## $equidist
## [1] TRUE
## 
## attr(,"class")
## [1] "histogram"
## 
## $`11580`
## $breaks
##  [1]  6  7  8  9 10 11 12 13 14 15 16 17 18
## 
## $counts
##  [1]  0  0  2  3  7 12  4  1  1  0  0  0
## 
## $density
##  [1] 0.00000000 0.00000000 0.06666667 0.10000000 0.23333333 0.40000000
##  [7] 0.13333333 0.03333333 0.03333333 0.00000000 0.00000000 0.00000000
## 
## $mids
##  [1]  6.5  7.5  8.5  9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5
## 
## $xname
## [1] "x$IQ"
## 
## $equidist
## [1] TRUE
## 
## attr(,"class")
## [1] "histogram"
## 
## $`1280`
## $breaks
##  [1]  6  7  8  9 10 11 12 13 14 15 16 17 18
## 
## $counts
##  [1] 0 3 3 4 4 1 0 0 0 0 0 0
## 
## $density
##  [1] 0.00000000 0.20000000 0.20000000 0.26666667 0.26666667 0.06666667
##  [7] 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000 0.00000000
## 
## $mids
##  [1]  6.5  7.5  8.5  9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5
## 
## $xname
## [1] "x$IQ"
## 
## $equidist
## [1] TRUE
## 
## attr(,"class")
## [1] "histogram"
## 
## $`3880`
## $breaks
##  [1]  6  7  8  9 10 11 12 13 14 15 16 17 18
## 
## $counts
##  [1] 0 1 2 6 4 6 4 3 1 1 0 0
## 
## $density
##  [1] 0.00000000 0.03571429 0.07142857 0.21428571 0.14285714 0.21428571
##  [7] 0.14285714 0.10714286 0.03571429 0.03571429 0.00000000 0.00000000
## 
## $mids
##  [1]  6.5  7.5  8.5  9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5
## 
## $xname
## [1] "x$IQ"
## 
## $equidist
## [1] TRUE
## 
## attr(,"class")
## [1] "histogram"
## 
## $`5780`
## $breaks
##  [1]  6  7  8  9 10 11 12 13 14 15 16 17 18
## 
## $counts
##  [1] 0 1 1 1 4 8 4 2 1 2 0 0
## 
## $density
##  [1] 0.00000000 0.04166667 0.04166667 0.04166667 0.16666667 0.33333333
##  [7] 0.16666667 0.08333333 0.04166667 0.08333333 0.00000000 0.00000000
## 
## $mids
##  [1]  6.5  7.5  8.5  9.5 10.5 11.5 12.5 13.5 14.5 15.5 16.5 17.5
## 
## $xname
## [1] "x$IQ"
## 
## $equidist
## [1] TRUE
## 
## attr(,"class")
## [1] "histogram"