R语言数据整理

基本操作

读入csv数据

data <- read.csv("D:/Project/180414/data.csv", header = TRUE)

写出csv数据

write.csv(data,file="D:/Project/180414/data1.csv")

安装包调用R语言包

install.packages("psych")#安装包
library("psych")#调用包

数据框

创建数据框

schools <- data.frame(school = c("A","B","C","D","E","F","G","H"),
                      eatimate = c(28.39,7.94,-2.75,6.82,-0.64,0.63,18.01,12.16),
                      sd = c(14.9,10.2,16.3,11.0,9.4,11.4,10.4,17.6))

选择行/列组成新的数据框

c_data <- data[data$site == 'beijing',]#按内容选择
  
c_data <- data[data$site %in% c("beijing","tianjin","shandong"),]#按内容选择多行

c_data <- data[,2:4]#选择第2,3,4列

把列数据组成新的数据框

mydataframe <- data.frame(m1,m2,m4,m5)

数据框/矩阵的转置

data <- t(data)

矩阵

data <- matrix(nrow = , ncol = )#新建2行3列NA矩阵

数据类型装换

把因子转为数值型

  x <- as.numeric(as.character(x))#因子型转数值型，应先转字符型

构建函数

change <-function(x){
  x <- as.numeric(as.character(x))
}