?Vocab
## No documentation for 'Vocab' in specified packages and libraries:
## you could try '??Vocab'
head(carData::Vocab)
## year sex education vocabulary
## 19740001 1974 Male 14 9
## 19740002 1974 Male 16 9
## 19740003 1974 Female 10 9
## 19740004 1974 Female 10 5
## 19740005 1974 Female 12 8
## 19740006 1974 Male 16 8
##前六列看趨勢
dta<- carData::Vocab
pacman::p_load(lattice)
##切割檔案
dta1974 <- subset(dta, dta$year=="1974")
xyplot(vocabulary ~ education, groups=sex, data=dta1974, type=c("p", "g"), auto.key=list(columns=2))

dta1984 <- subset(dta, dta$year=="1984")
xyplot(vocabulary ~ education, groups=sex, data=dta1984, type=c("p", "g"), auto.key=list(columns=2))

dta1994 <- subset(dta, dta$year=="1994")
xyplot(vocabulary ~ education, groups=sex, data=dta1994, type=c("p", "g"), auto.key=list(columns=2))

dta2004 <- subset(dta, dta$year=="2004")
xyplot(vocabulary ~ education, groups=sex, data=dta2004, type=c("p", "g"), auto.key=list(columns=2))

##終於一次全部呈現,大體上隨著教育年數的增長,單字量也會增加
lattice::xyplot(vocabulary ~ education | year, groups = sex, type = c("p", "g", "r"), data =dta , auto.key = list(columns = 2), xlab = "Education", ylab = "Vocabulary")

##男性識字和年代迴歸較為穩定
malec <- subset(dta, dta$sex=="Male")
lapply(split(malec, malec$year), function(x) coef(lm(x$vocabulary ~ x$education)))
## $`1974`
## (Intercept) x$education
## 1.5318434 0.3713183
##
## $`1976`
## (Intercept) x$education
## 1.6342960 0.3555403
##
## $`1978`
## (Intercept) x$education
## 0.9762161 0.3963762
##
## $`1982`
## (Intercept) x$education
## 0.9730291 0.3832637
##
## $`1984`
## (Intercept) x$education
## 1.678465 0.337124
##
## $`1987`
## (Intercept) x$education
## 0.8103651 0.3818373
##
## $`1988`
## (Intercept) x$education
## 1.0459936 0.3592442
##
## $`1989`
## (Intercept) x$education
## 1.0596176 0.3708525
##
## $`1990`
## (Intercept) x$education
## 1.7000935 0.3377029
##
## $`1991`
## (Intercept) x$education
## 1.2504604 0.3683962
##
## $`1993`
## (Intercept) x$education
## 1.6384884 0.3221049
##
## $`1994`
## (Intercept) x$education
## 1.8684770 0.3146151
##
## $`1996`
## (Intercept) x$education
## 0.8221711 0.3770325
##
## $`1998`
## (Intercept) x$education
## 1.5199973 0.3314754
##
## $`2000`
## (Intercept) x$education
## 1.1203888 0.3558918
##
## $`2004`
## (Intercept) x$education
## 1.4259424 0.3411153
##
## $`2006`
## (Intercept) x$education
## 2.1383454 0.2952926
##
## $`2008`
## (Intercept) x$education
## 1.4212286 0.3277987
##
## $`2010`
## (Intercept) x$education
## 1.7996389 0.3135749
##
## $`2012`
## (Intercept) x$education
## 1.7303105 0.3061534
##
## $`2014`
## (Intercept) x$education
## 1.4804789 0.3262112
##
## $`2016`
## (Intercept) x$education
## 1.8562367 0.3031146
##女性識字和年代迴歸隨年代有下降趨勢
femalec <- subset(dta, dta$sex=="Female")
lapply(split(femalec, femalec$year), function(x) coef(lm(x$vocabulary ~ x$education)))
## $`1974`
## (Intercept) x$education
## 1.5652579 0.3816095
##
## $`1976`
## (Intercept) x$education
## 1.7021281 0.3824002
##
## $`1978`
## (Intercept) x$education
## 1.3006416 0.4002707
##
## $`1982`
## (Intercept) x$education
## 0.9829602 0.3949758
##
## $`1984`
## (Intercept) x$education
## 1.4536872 0.3728698
##
## $`1987`
## (Intercept) x$education
## 0.9647931 0.3843508
##
## $`1988`
## (Intercept) x$education
## 1.1634561 0.3763999
##
## $`1989`
## (Intercept) x$education
## 1.0682600 0.3863606
##
## $`1990`
## (Intercept) x$education
## 0.4594812 0.4346902
##
## $`1991`
## (Intercept) x$education
## 1.1543766 0.3875821
##
## $`1993`
## (Intercept) x$education
## 1.7388287 0.3286325
##
## $`1994`
## (Intercept) x$education
## 1.6453365 0.3422146
##
## $`1996`
## (Intercept) x$education
## 1.1482811 0.3727178
##
## $`1998`
## (Intercept) x$education
## 1.4472751 0.3592843
##
## $`2000`
## (Intercept) x$education
## 1.9276040 0.3155532
##
## $`2004`
## (Intercept) x$education
## 2.104150 0.304056
##
## $`2006`
## (Intercept) x$education
## 2.7777171 0.2535376
##
## $`2008`
## (Intercept) x$education
## 2.6074315 0.2553971
##
## $`2010`
## (Intercept) x$education
## 1.3520300 0.3468821
##
## $`2012`
## (Intercept) x$education
## 1.7535298 0.3080832
##
## $`2014`
## (Intercept) x$education
## 2.3445239 0.2663464
##
## $`2016`
## (Intercept) x$education
## 2.0055919 0.2928955