第二章 数据
dir.create('c:/r4r')
write.csv(as.data.frame(t(matrix(
co2, 12, dimnames = list(
month.abb, unique(floor(time(co2))))))),
file = 'c:/r4r/co2.csv')
mydata1 <- read.table(file = "clipboard", header = TRUE)
mydata1
myfile1 <- file.choose()
myfile1 <- "c:/r4r/co2.csv"
myfile1
myfile2 <- "c:/r4r/co2.csv"
myfile2
file.show(myfile2) # 查看文件
mydata2 <- read.table(file = myfile2,
header = TRUE, sep = ",")
mydata2
mydata2 <- read.csv(file = myfile2)
mydata2 <- read.csv(file = "c:/r4r/co2.csv")
plot(mydata2)
summary(mydata2)
mydata2[37, 10]
mydata2[c(2, 4, 6, 8, 10, 12, 14, 16, 18, 20,
22, 24, 26, 28, 30, 32, 34, 36, 38), 10]
mydata2[seq(from = 2, to = 39, by = 2), 10]
mydata2[2:39, 10]
mydata2[, 10] # 第10列全部。
mydata2[37, ] # 第37行全部。
mydata2[, 'Sep']
mydata2$Sep
names(mydata2) # 或 colnames(mydata2)
names(mydata2)[1] <- 'year'
names(mydata2)
rownames(mydata2)
rownames(mydata2) <- mydata2$year
rownames(mydata2)
mydata2['1995', 'Sep']
sum(mydata2['1995', 2:13]) / 12
sum(mydata2['1996', 2:13]) / 12 -
sum(mydata2['1995', 2:13]) / 12
mydata2['1996', ] - mydata2['1995', ]
colMeans(mydata2[, 2:13]) # 排除掉第一列后,对整列求平均
mydata2$mean <- rowMeans(mydata2[, 2:13])
mydata2$median <- apply(X = mydata2[, 2:13],
FUN = median, MARGIN = 1)
diff(mydata2$Sep)