Multilevel Analysis 9/17 Homework-1

library(mlmRev)

## 載入需要的套件：lme4

## 載入需要的套件：Matrix

library(tidyverse)

## ── Attaching packages
## ───────────────────────────────────────
## tidyverse 1.3.2 ──

## ✔ ggplot2 3.3.6      ✔ purrr   0.3.4 
## ✔ tibble  3.1.8      ✔ dplyr   1.0.10
## ✔ tidyr   1.2.1      ✔ stringr 1.4.1 
## ✔ readr   2.1.2      ✔ forcats 0.5.2 
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ tidyr::expand() masks Matrix::expand()
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ✖ tidyr::pack()   masks Matrix::pack()
## ✖ tidyr::unpack() masks Matrix::unpack()

## 讀取data
data(Gcsemv, package="mlmRev")
dta <- Gcsemv

## 計算各學校平均 
dta_a <- dta %>%
        group_by(school) %>%
        summarize(ave_written =mean(written, na.rm=TRUE),
                    ave_course = mean(course, na.rm=TRUE))

## superimpose two plots
ggplot(data=dta, aes(x=written, y=course)) +
 geom_point(color="skyblue") +
 stat_smooth(method="lm", formula=y ~ x, se=F, col="skyblue") +
 geom_point(data=dta_a, aes(ave_written, ave_course), color="steelblue") +
 stat_smooth(data=dta_a, aes(ave_written, ave_course),
             method="lm", formula= y ~ x, se=F, color="steelblue") +
 labs(x="Written score", 
      y="Course score") +
 theme_bw()

## Warning: Removed 382 rows containing non-finite values (stat_smooth).

## Warning: Removed 382 rows containing missing values (geom_point).