[R] R Help

[Rami Alzebdieh]

Dear Sir,

I start using (R) 3 months ago, and I am still learning, I have a project and I am using R in this project, my friend helped me to build a code for this project and it's working perfect, but I need to make a small change in, it looks very simple but for me it's very complicated. I insert the code and I hope if you can help me this problem. I highlighted what exactly I need to change. This project is calculating the market and industry weighted returns for each based on the date levels.

sync = read.csv("country-14.csv",header=T)
id.country = 14

sync = sync[sync$country!="country" & sync$country==id.country,-c(2,5)]
sync$price=as.numeric(as.character(sync$price))
sync$mv=as.numeric(as.character(sync$mv))
attach(sync)

#### Calculate returns and add to the dataset
n.comp = nlevels(as.factor(as.character(sync$company_name)))
comp.names = levels(as.factor(as.character(sync$company_name)))
data = vector("list",n.comp)
for(i in 1:n.comp){
  temp = sync[sync$company_name==comp.names[i],]
  data[[i]] = cbind(temp,c(NA,diff(temp$price)/temp$price[1:(length(temp$price)-1)]))
}
sync = do.call(rbind,data)
names(sync)[7] = "returns"
detach(sync)
attach(sync)

#### Fill industry_code column
industry_code=rep(NA,dim(sync)[1])
for(i in 1:dim(sync)[1]){
  if(nchar(as.character(company_code[i])) == 3){
    industry_code[i] = as.numeric(substr(as.character(company_code[i]),1,1))
  } else {
    industry_code[i] = as.numeric(substr(as.character(company_code[i]),1,2))
  }
  print((i/dim(sync)[1])*100)
}
sync = cbind(sync,as.factor(industry_code))
names(sync)[8] = "industry_code"
detach(sync)
attach(sync)

#### Calculate market weighted returns and add to the dataset
market_returns = rep(NA,dim(sync)[1])
industry_returns = rep(NA,dim(sync)[1])
for(i in 1:nlevels(date)){
    data = sync[date==levels(date)[i],]
    data$company_name = as.factor(as.character(data$company_name))
    for(m in 1:nlevels(data$company_name)){
      index1 = data$company_name == levels(data$company_name)[m]
      index2 = date==levels(date)[i] & company_name==levels(data$company_name)[m]
      market_returns[index2] = (sum(data$returns*(data$mv/sum(data$mv,na.rm=TRUE)),na.rm=TRUE) -
        (data$returns[index1]*(data$mv[index1]/sum(data$mv,na.rm=TRUE))))/(nlevels(data$company_name)-1) ## this what I need to change, instead of using the number of levels companies in the dataset (nlevels(data$company_name) , I need to put the number of returns values(data$returns) without NA (by the way this code is calculating returns at the date level as you can see from above)
    }
  print(i/nlevels(date))
}

sync = cbind(sync,market_returns)
names(sync)[9] = "market_returns"
detach(sync)
attach(sync)

#### Calculate industry weighted returns and add to the dataset
for(i in 1:nlevels(date)){
    for(k in 1:nlevels(as.factor(as.character(industry_code)))){
      data1 = sync[date==levels(date)[i] & industry_code==levels(as.factor(as.character(industry_code)))[k],]
      data1$company_name = as.factor(as.character(data1$company_name))
      for(l in 1:nlevels(data1$company_name)){
        index3 = data1$company_name == levels(data1$company_name)[l]
        index4 = date==levels(date)[i] & company_name==levels(data1$company_name)[l]
        industry_returns[index4] = (sum(data1$returns*(data1$mv/sum(data1$mv,na.rm=TRUE)),na.rm=TRUE) -
          (data1$returns[index3]*(data1$mv[index3]/sum(data1$mv,na.rm=TRUE))))/(nlevels(data1$company_name)-1) ## also here I need to change, instead of using the number of levels companies in the dataset (nlevels(data1$company_name) , I need to put the number of returns values(data1$returns) without NA (by the way this code is calculating returns at the date level and industry level as you can see from above)

      }
    }
  print(i/nlevels(date))
}

sync = cbind(sync,industry_returns)
names(sync)[10] = "industry_returns"
detach(sync)
attach(sync)

year = apply(as.matrix(sync$date),1,function(x) as.factor(substr(as.character(x),7,10)))
sync = cbind(sync,as.factor(year))
names(sync)[11] = "year"
sync = sync[sync$year!="1999",]
sync$year = as.factor(as.character(sync$year))
detach(sync)
attach(sync)

year = as.factor(as.character(year))
industry_code = as.factor(as.character(industry_code))
comp.per.ind = rep(NA, dim(sync)[1])
for(i in 1:nlevels(year)){
  for(j in 1:nlevels(industry_code)){
    index = year==levels(year)[i] & industry_code==levels(industry_code)[j]
    data = sync[index,]
    comp.per.ind[index] = nlevels(as.factor(as.character(data$company_name)))
  }
}

sync = cbind(sync,as.factor(comp.per.ind))
names(sync)[12] = "comp.per.ind"
detach(sync)
attach(sync)

write.csv(sync,paste("Returns_data",id.country,".csv",sep=""))




Thank you for your help

Rami Alzebdieh



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