library(dplyr)
library(tidyr)
library(ggplot2)

Ex2

dta <- Ecdat::Caschool
head(dta)
##   distcod  county                        district grspan enrltot teachers
## 1   75119 Alameda              Sunol Glen Unified  KK-08     195    10.90
## 2   61499   Butte            Manzanita Elementary  KK-08     240    11.15
## 3   61549   Butte     Thermalito Union Elementary  KK-08    1550    82.90
## 4   61457   Butte Golden Feather Union Elementary  KK-08     243    14.00
## 5   61523   Butte        Palermo Union Elementary  KK-08    1335    71.50
## 6   62042  Fresno         Burrel Union Elementary  KK-08     137     6.40
##   calwpct mealpct computer testscr   compstu  expnstu      str    avginc
## 1  0.5102  2.0408       67  690.80 0.3435898 6384.911 17.88991 22.690001
## 2 15.4167 47.9167      101  661.20 0.4208333 5099.381 21.52466  9.824000
## 3 55.0323 76.3226      169  643.60 0.1090323 5501.955 18.69723  8.978000
## 4 36.4754 77.0492       85  647.70 0.3497942 7101.831 17.35714  8.978000
## 5 33.1086 78.4270      171  640.85 0.1280899 5235.988 18.67133  9.080333
## 6 12.3188 86.9565       25  605.55 0.1824818 5580.147 21.40625 10.415000
##       elpct readscr mathscr
## 1  0.000000   691.6   690.0
## 2  4.583333   660.5   661.9
## 3 30.000002   636.3   650.9
## 4  0.000000   651.9   643.5
## 5 13.857677   641.8   639.9
## 6 12.408759   605.7   605.4
set.seed(123456)
dta2 <- dta %>% 
  group_by(county) %>% 
  sample_n(1)

plot(dta2$mathscr,dta2$readscr,
     xlab = "Average math score", ylab = "Average reading score")

EX3

options(continue = "  ") #設置換行符號
options(digits = 3) #設置小數位數
options(width = 72) #設置資訊寬度
ds = read.csv("http://www.amherst.edu/~nhorton/r2/datasets/help.csv") 
library(dplyr)
newds = select(ds, cesd, female, i1, i2, id, treat, f1a, f1b, f1c, f1d, f1e, 
  f1f, f1g, f1h, f1i, f1j, f1k, f1l, f1m, f1n, f1o, f1p, f1q, f1r, f1s, f1t) #選取變項存成新的data.frame


names(newds) #檢視變項名稱
##  [1] "cesd"   "female" "i1"     "i2"     "id"     "treat"  "f1a"   
##  [8] "f1b"    "f1c"    "f1d"    "f1e"    "f1f"    "f1g"    "f1h"   
## [15] "f1i"    "f1j"    "f1k"    "f1l"    "f1m"    "f1n"    "f1o"   
## [22] "f1p"    "f1q"    "f1r"    "f1s"    "f1t"
summary(newds[,1:10]) #檢視前10個變項的概要
##       cesd          female            i1              i2       
##  Min.   : 1.0   Min.   :0.000   Min.   :  0.0   Min.   :  0.0  
##  1st Qu.:25.0   1st Qu.:0.000   1st Qu.:  3.0   1st Qu.:  3.0  
##  Median :34.0   Median :0.000   Median : 13.0   Median : 15.0  
##  Mean   :32.8   Mean   :0.236   Mean   : 17.9   Mean   : 22.6  
##  3rd Qu.:41.0   3rd Qu.:0.000   3rd Qu.: 26.0   3rd Qu.: 32.0  
##  Max.   :60.0   Max.   :1.000   Max.   :142.0   Max.   :184.0  
##        id          treat            f1a            f1b      
##  Min.   :  1   Min.   :0.000   Min.   :0.00   Min.   :0.00  
##  1st Qu.:119   1st Qu.:0.000   1st Qu.:1.00   1st Qu.:0.00  
##  Median :233   Median :0.000   Median :2.00   Median :1.00  
##  Mean   :233   Mean   :0.497   Mean   :1.63   Mean   :1.39  
##  3rd Qu.:348   3rd Qu.:1.000   3rd Qu.:3.00   3rd Qu.:2.00  
##  Max.   :470   Max.   :1.000   Max.   :3.00   Max.   :3.00  
##       f1c            f1d      
##  Min.   :0.00   Min.   :0.00  
##  1st Qu.:1.00   1st Qu.:0.00  
##  Median :2.00   Median :1.00  
##  Mean   :1.92   Mean   :1.56  
##  3rd Qu.:3.00   3rd Qu.:3.00  
##  Max.   :3.00   Max.   :3.00
head(newds, n=3) #檢視資料前3列
##   cesd female i1 i2 id treat f1a f1b f1c f1d f1e f1f f1g f1h f1i f1j
## 1   49      0 13 26  1     1   3   2   3   0   2   3   3   0   2   3
## 2   30      0 56 62  2     1   3   2   0   3   3   2   0   0   3   0
## 3   39      0  0  0  3     0   3   2   3   0   2   2   1   3   2   3
##   f1k f1l f1m f1n f1o f1p f1q f1r f1s f1t
## 1   3   0   1   2   2   2   2   3   3   2
## 2   3   0   0   3   0   0   0   2   0   0
## 3   1   0   1   3   2   0   0   3   2   0
comment(newds) = "HELP baseline dataset" #為data.frame下註解
comment(newds) #檢視註解
## [1] "HELP baseline dataset"
save(ds, file="savedfile") #將原始資料存檔


write.csv(ds, file="ds.csv") #將原始資料存為csv檔


library(foreign) #載入foreign套件
write.foreign(newds, "file.dat", "file.sas", package="SAS") #將資料存為sas檔


with(newds, cesd[1:10]) #檢視變項cesd的前10個資料
##  [1] 49 30 39 15 39  6 52 32 50 46
with(newds, head(cesd, 10)) #檢視變項cesd的前10個資料
##  [1] 49 30 39 15 39  6 52 32 50 46
with(newds, cesd[cesd > 56]) #檢視變項cesd中大於56的資料
## [1] 57 58 57 60 58 58 57
library(dplyr) 
filter(newds, cesd > 56) %>% 
  select(id, cesd) #過濾出cesd大於56的資料,並選取id和cesd兩個變項
## Warning: package 'bindrcpp' was built under R version 3.4.3
##    id cesd
## 1  71   57
## 2 127   58
## 3 200   57
## 4 228   60
## 5 273   58
## 6 351   58
## 7  13   57
with(newds, sort(cesd)[1:4]) #將變項cesd的資料由小排到大,並選取前4個資料
## [1] 1 3 3 4
with(newds, which.min(cesd)) #變項cesd中最小值的位置
## [1] 199
library(mosaic) #載入mosaic套件
tally(~ is.na(f1g), data=newds) #計算f1g變項中是和不是NA的數量
## is.na(f1g)
##  TRUE FALSE 
##     1   452
favstats(~ f1g, data=newds) #呈現f1g變項的各項統計屬性(極值、四分位數、平均值、標準差、總數、無效值數)
##  min Q1 median Q3 max mean  sd   n missing
##    0  1      2  3   3 1.73 1.1 452       1
cesditems = with(newds, cbind(f1a, f1b, f1c, (3 - f1d), f1e, f1f, f1g, 
   (3 - f1h), f1i, f1j, f1k, (3 - f1l), f1m, f1n, f1o, (3 - f1p), 
   f1q, f1r, f1s, f1t)) #將f1d、f1h、f1l、f1p值作反轉
nmisscesd = apply(is.na(cesditems), 1, sum) #按列計算NA數
ncesditems = cesditems #用另一個data.frame儲存
ncesditems[is.na(cesditems)] = 0 #將資料中的NA替換成0
newcesd = apply(ncesditems, 1, sum) #按列計算總和
imputemeancesd = 20/(20-nmisscesd)*newcesd #計算各列總和,若有NA值以該列平均值填補


data.frame(newcesd, newds$cesd, nmisscesd, imputemeancesd)[nmisscesd>0,] #檢視有NA值的列資料
##     newcesd newds.cesd nmisscesd imputemeancesd
## 4        15         15         1           15.8
## 17       19         19         1           20.0
## 87       44         44         1           46.3
## 101      17         17         1           17.9
## 154      29         29         1           30.5
## 177      44         44         1           46.3
## 229      39         39         1           41.1
library(dplyr) #載入dplyr套件
library(memisc) #載入memisc套件
## Warning: package 'memisc' was built under R version 3.4.4
## Loading required package: MASS
## Warning: package 'MASS' was built under R version 3.4.3
## 
## Attaching package: 'MASS'
## The following object is masked from 'package:dplyr':
## 
##     select
## 
## Attaching package: 'memisc'
## The following object is masked from 'package:Matrix':
## 
##     as.array
## The following objects are masked from 'package:dplyr':
## 
##     collect, recode, rename
## The following objects are masked from 'package:stats':
## 
##     contr.sum, contr.treatment, contrasts
## The following object is masked from 'package:base':
## 
##     as.array
newds = mutate(newds, drinkstat= #加入新變項drinkstat
  cases( #設條件
    "abstinent" = i1==0, #i1為0
    "moderate" = (i1>0 & i1<=1 & i2<=3 & female==1) | #i1大於0且小於等於1,i2小於等於3,為女性
               (i1>0 & i1<=2 & i2<=4 & female==0), #i1大於0且小於等於2,i2小於等於4,為男性
    "highrisk" = ((i1>1 | i2>3) & female==1) | #i1大於1或i2大於3,為女性
               ((i1>2 | i2>4) & female==0))) #i1大於2或i2大於4,為男性


library(mosaic) #載入mosaic套件


detach(package:memisc) #取消memisc套件的連結
detach(package:MASS) #取消MASS套件的連結


library(dplyr) #載入dplyr套件
tmpds = select(newds, i1, i2, female, drinkstat) #選取變項
tmpds[365:370,] #選取第365筆到第370筆資料
##     i1 i2 female drinkstat
## 365  6 24      0  highrisk
## 366  6  6      0  highrisk
## 367  0  0      0 abstinent
## 368  0  0      1 abstinent
## 369  8  8      0  highrisk
## 370 32 32      0  highrisk
library(dplyr) #載入dplyr套件
filter(tmpds, drinkstat=="moderate" & female==1) #篩選出飲酒狀態適中且為女性的資料
##   i1 i2 female drinkstat
## 1  1  1      1  moderate
## 2  1  3      1  moderate
## 3  1  2      1  moderate
## 4  1  1      1  moderate
## 5  1  1      1  moderate
## 6  1  1      1  moderate
## 7  1  1      1  moderate
library(gmodels) #載入gmodels套件
## Warning: package 'gmodels' was built under R version 3.4.4
with(tmpds, CrossTable(drinkstat)) #檢視變項drinkstat的表格
## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  453 
## 
##  
##           | abstinent |  moderate |  highrisk | 
##           |-----------|-----------|-----------|
##           |        68 |        28 |       357 | 
##           |     0.150 |     0.062 |     0.788 | 
##           |-----------|-----------|-----------|
## 
## 
## 
## 
with(tmpds, CrossTable(drinkstat, female, 
  prop.t=FALSE, prop.c=FALSE, prop.chisq=FALSE)) #檢視變項drinkstat和變項female的交叉表格
## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## |           N / Row Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  453 
## 
##  
##              | female 
##    drinkstat |         0 |         1 | Row Total | 
## -------------|-----------|-----------|-----------|
##    abstinent |        42 |        26 |        68 | 
##              |     0.618 |     0.382 |     0.150 | 
## -------------|-----------|-----------|-----------|
##     moderate |        21 |         7 |        28 | 
##              |     0.750 |     0.250 |     0.062 | 
## -------------|-----------|-----------|-----------|
##     highrisk |       283 |        74 |       357 | 
##              |     0.793 |     0.207 |     0.788 | 
## -------------|-----------|-----------|-----------|
## Column Total |       346 |       107 |       453 | 
## -------------|-----------|-----------|-----------|
## 
## 
newds = transform(newds, 
  gender=factor(female, c(0,1), c("Male","Female"))) #新增變項gender紀錄性別
tally(~ female + gender, margin=FALSE, data=newds) #檢視變項female和變項gender的數量關係
##       gender
## female Male Female
##      0  346      0
##      1    0    107
library(dplyr) #載入dplyr套件
newds = arrange(ds, cesd, i1) #按照變項cesd和變項i1的大小排序資料
newds[1:5, c("cesd", "i1", "id")] #檢視前5筆資料,並只選取cesd、i1、id三個變項
##   cesd i1  id
## 1    1  3 233
## 2    3  1 139
## 3    3 13 418
## 4    4  4 251
## 5    4  9  95
library(dplyr) #載入dplyr套件
females = filter(ds, female==1) #篩選出變項female等於1的資料
with(females, mean(cesd)) #計算cesd的平均值
## [1] 36.9
# an alternative approach
mean(ds$cesd[ds$female==1]) #計算變項female等於1的資料中,cesd的平均值
## [1] 36.9
with(ds, tapply(cesd, female, mean)) #計算變項female的兩個狀況下,cesd的平均值
##    0    1 
## 31.6 36.9
library(mosaic) #載入mosaic套件
mean(cesd ~ female, data=ds) #計算變項female的兩個狀況下,cesd的平均值
##    0    1 
## 31.6 36.9

EX4

dta4 <- HSAUR3::backpain
head(dta4)
##   ID  status driver suburban
## 1  1    case    yes      yes
## 2  1 control    yes       no
## 3  2    case    yes      yes
## 4  2 control    yes      yes
## 5  3    case    yes       no
## 6  3 control    yes      yes
dta4 <- dta4 %>% 
  group_by(status,driver,suburban) %>% 
  summarise(n = n()) %>% 
  ungroup() %>% 
  tidyr::spread(status,n) %>% 
  mutate(total = case + control); dta4
## # A tibble: 4 x 5
##   driver suburban  case control total
##   <fct>  <fct>    <int>   <int> <int>
## 1 no     no          26      47    73
## 2 no     yes          6       7    13
## 3 yes    no          64      63   127
## 4 yes    yes        121     100   221

Ex5

library(datasets)
dta5 <- merge(state.x77, USArrests,"row.names")
cor(dta5[,-1])
##            Population  Income Illiteracy Life Exp Murder.x HS Grad
## Population     1.0000  0.2082     0.1076  -0.0681   0.3436 -0.0985
## Income         0.2082  1.0000    -0.4371   0.3403  -0.2301  0.6199
## Illiteracy     0.1076 -0.4371     1.0000  -0.5885   0.7030 -0.6572
## Life Exp      -0.0681  0.3403    -0.5885   1.0000  -0.7808  0.5822
## Murder.x       0.3436 -0.2301     0.7030  -0.7808   1.0000 -0.4880
## HS Grad       -0.0985  0.6199    -0.6572   0.5822  -0.4880  1.0000
## Frost         -0.3322  0.2263    -0.6719   0.2621  -0.5389  0.3668
## Area           0.0225  0.3633     0.0773  -0.1073   0.2284  0.3335
## Murder.y       0.3202 -0.2152     0.7068  -0.7785   0.9337 -0.5216
## Assault        0.3170  0.0409     0.5110  -0.6267   0.7398 -0.2303
## UrbanPop       0.5126  0.4805    -0.0622   0.2715   0.0164  0.3587
## Rape           0.3052  0.3574     0.1546  -0.2696   0.5800  0.2707
##              Frost    Area Murder.y Assault UrbanPop   Rape
## Population -0.3322  0.0225   0.3202  0.3170   0.5126  0.305
## Income      0.2263  0.3633  -0.2152  0.0409   0.4805  0.357
## Illiteracy -0.6719  0.0773   0.7068  0.5110  -0.0622  0.155
## Life Exp    0.2621 -0.1073  -0.7785 -0.6267   0.2715 -0.270
## Murder.x   -0.5389  0.2284   0.9337  0.7398   0.0164  0.580
## HS Grad     0.3668  0.3335  -0.5216 -0.2303   0.3587  0.271
## Frost       1.0000  0.0592  -0.5414 -0.4682  -0.2462 -0.279
## Area        0.0592  1.0000   0.1481  0.2312  -0.0615  0.525
## Murder.y   -0.5414  0.1481   1.0000  0.8019   0.0696  0.564
## Assault    -0.4682  0.2312   0.8019  1.0000   0.2589  0.665
## UrbanPop   -0.2462 -0.0615   0.0696  0.2589   1.0000  0.411
## Rape       -0.2792  0.5250   0.5636  0.6652   0.4113  1.000
GGally::ggpairs(dta5[,-1])

Ex6

library(MASS)
library(tibble)
dta6 <- merge(rownames_to_column(mammals), rownames_to_column(Animals), all = TRUE)
duplicated(dta6)
##  [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [12] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [23] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [34] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [45] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [56] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [67] FALSE

Ex7

library(Ecdat)
dta7 <- Caschool %>% 
  mutate(ratio = enrltot/teachers, Reading = cut(readscr, breaks = quantile(readscr, probs = c(0, .33, .67, 1)), label = c("L", "M", "H"), ordered = T))

library(lattice)
xyplot(readscr ~ ratio | Reading, data = dta7,
                type = c("p", "g", "r"), layout = c(3, 1),
                xlab = "Student-Teacher Ratio",
                ylab = "Reading Score")

Ex8-1

dta8<-car::Prestige
head(dta8)
##                     education income women prestige census type
## gov.administrators       13.1  12351 11.16     68.8   1113 prof
## general.managers         12.3  25879  4.02     69.1   1130 prof
## accountants              12.8   9271 15.70     63.4   1171 prof
## purchasing.officers      11.4   8865  9.11     56.8   1175 prof
## chemists                 14.6   8403 11.68     73.5   2111 prof
## physicists               15.6  11030  5.13     77.6   2113 prof
dta8_1 <- dta8 %>% 
  group_by(type) %>% 
  summarize(m = median(prestige,na.rm = TRUE));dta8_1
## # A tibble: 4 x 2
##   type      m
##   <fct> <dbl>
## 1 bc     35.9
## 2 prof   68.4
## 3 wc     41.5
## 4 <NA>   35.0

Ex8-2

dta8_2 <- dta8 %>% 
  na.omit %>% 
  group_by(type) %>% 
  mutate(m = median(prestige),
  PrestigeLV = memisc::cases("H" = prestige >= m,"Low" = prestige < m))

#繪圖
xyplot(income ~ education|type, 
       group = PrestigeLV, 
       data = dta8_2, 
       type = c("p","g","r"),
       layout = c(3, 1),
       auto.key = list(space = "right", row = 2),
       xlab = "Average education of occupational incumbents in 1971",
       ylab = "Average income of incumbents in 1971")

Ex9

library(mlmRev)
## Warning: package 'mlmRev' was built under R version 3.4.4
## Loading required package: lme4
## 
## Attaching package: 'lme4'
## The following object is masked from 'package:mosaic':
## 
##     factorize
dta_09 <- Hsb82
head(dta_09)
##   school minrty     sx    ses  mAch meanses sector    cses
## 1   1224     No Female -1.528  5.88  -0.434 Public -1.0936
## 2   1224     No Female -0.588 19.71  -0.434 Public -0.1536
## 3   1224     No   Male -0.528 20.35  -0.434 Public -0.0936
## 4   1224     No   Male -0.668  8.78  -0.434 Public -0.2336
## 5   1224     No   Male -0.158 17.90  -0.434 Public  0.2764
## 6   1224     No   Male  0.022  4.58  -0.434 Public  0.4564
dta_09 <- Hsb82 %>%
  group_by(sector,school) %>%
  summarise(m = mean(mAch, na.rm = TRUE),
            s = sd(mAch, na.rm = TRUE),
            n = n(),
            se = s/sqrt(n)) %>%
  mutate(lower.ci = m-2*se, upper.ci = m+2*se)
head(dta_09)
## # A tibble: 6 x 8
## # Groups:   sector [1]
##   sector school     m     s     n    se lower.ci upper.ci
##   <fct>  <ord>  <dbl> <dbl> <int> <dbl>    <dbl>    <dbl>
## 1 Public 8367    4.55  4.43    14 1.18      2.19     6.92
## 2 Public 8854    4.24  5.41    32 0.956     2.33     6.15
## 3 Public 4458    5.81  4.48    48 0.646     4.52     7.10
## 4 Public 5762    4.32  4.99    37 0.821     2.68     5.97
## 5 Public 6990    5.98  5.31    53 0.729     4.52     7.44
## 6 Public 5815    7.27  5.59    25 1.12      5.04     9.51
ggplot(dta_09, aes(x = school, y = m)) +
  geom_point() +
  geom_errorbar(aes(ymax = upper.ci, ymin = lower.ci))+
  coord_flip()+
  facet_wrap(~sector)+
  labs(x = "School",y = "Math Mean Score by School")