2020-03-23 Homework-5

讀取檔案

dta <- read.table("C:/Users/X510/Desktop/2020-03-23 Homework-5/schiz.asc.txt", sep = " ", skip = 4)

依照題目分為兩組

dta$Group <- c(rep("non-schizo", 11),rep("schizo", 6))

長寬表互換

library(reshape2)
data <- melt(dta, id.vars=c("Group"))
colnames(data)[2:3] <- c("Time", "RTime")
names(data)

## [1] "Group" "Time"  "RTime"

兩組平均數

aggregate(data$RTime~data$Group, mean, data=data)

##   data$Group data$RTime
## 1 non-schizo   310.1697
## 2     schizo   506.8667

盒狀圖

boxplot(RTime~Group, data=data)

T考驗

t.test(data$RTime~data$Group, data=data)

## 
##  Welch Two Sample t-test
## 
## data:  data$RTime by data$Group
## t = -9.8771, df = 190.98, p-value < 2.2e-16
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -235.9773 -157.4166
## sample estimates:
## mean in group non-schizo     mean in group schizo 
##                 310.1697                 506.8667