第三讲 经济学中的函数和方程

樊潇彦 复旦大学经济学院 经济数学

1. 课件下载

Ch03.pdf1398.3kB

2. 作图程序附录

# 准备工作
setwd("D:\\...")
rm(list=ls())
install.packages("dplyr")
install.packages("data.table")
install.packages("ggplot2")
library(dplyr)
library(data.table)
library(ggplot2)

数据下载
Ch3_data.rar128.1kB

2.1 恩格尔定律

engel=read.csv("CME_Consmp3.csv",header=T,skip=2,stringsAsFactors = F)
engel1=engel[,c(1,2,6)]
engel2=engel[,c(1,3,7)]
colnames(engel1)=colnames(engel2)=c("year","inc","engel")
engel=rbind(data.frame(urbdum=0,engel1),data.frame(urbdum=1,engel2))
engel=engel%>%
  filter(year>=1980 & year<=2013)%>%
  mutate(urbdum=as.factor(urbdum))%>%
  arrange(urbdum,year)
ggplot(data=engel,aes(x=inc,y=engel,group=urbdum,color=urbdum)) +
  geom_path()+
  labs(title ="城乡居民家庭恩格尔系数(%)", x = "", y = "") +
  theme_bw()

2.2 汇率

Exdata=read.csv("FE_Exrated.csv",header=T,stringsAsFactors = F)
Exdata=Exdata%>%
  mutate(Date=as.Date(Date))%>%
  arrange(Curcd,Date)
colnames(Exdata)=c("Date","Currency","E")
Ex=Exdata%>%
  filter(Currency %in% c("USD","EUR","JPY"))
Ex$E[which(Ex$Currency!="JPY")]=Ex$E[which(Ex$Currency!="JPY")]/100  # 美元和欧元转换为1单位外币兑人民币
Ex$E[which(Ex$Date==as.Date("2014-11-18") & Ex$Currency=="JPY")]=5.265000 # 修正错误数据
ggplot(data=Ex,aes(x=Date,y=E,color=Currency))+
  geom_line()+
  labs(title ="人民币基准汇价", x = "", y = "") +
  theme_bw()