calcurate confidence/predict interval and plot with a result of regression

confidence and predict interval

# import data
data <- read.delim(testadata.txt")

# execute regression and plot confidence/predict interval 
predict_continue <- function(target_method, target_cpa, interval) {
  d <- subset(data, method==target)
  # regression using log() transformation
  d.lm <- lm(continue~log(month)+cpa, data=d)
  summary(d.lm)
  
  # create prediction data
  monthes <- seq(1, 100, 1)
  cpas <- d$cpa
  for (i in 1:(100-nrow(d))) cpas <- append(cpas, target_cpa)
  methods <- target_method
  for(i in 1:(100-1)) methods <- append(methods, target_method)
  d.predict <- data.frame(month=monthes, cpa=cpas, method=methods)
  
  # calcurate confidence interval and plot
  if (span=="confidence") {
    d.lm.conficence <- predict(d.lm, d.predict, interval="confidence")
    plot(monthes, d.lm.conficence[,1], type="l", xlim=c(0,100), ylim=c(0,100), ylab="")
    par(new=T)
    plot(monthes, d.lm.conficence[,2], type="l", xlim=c(0,100), ylim=c(0,100), lty=2,col="red",ylab="")
    par(new=T)
    plot(monthes, d.lm.conficence[,3], type="l", xlim=c(0,100), ylim=c(0,100), lty=2,col="red",ylab="")
    par(new=T)
    plot(d$month, d$continue, type="p", xlim=c(0,100), ylim=c(0,100), lty=2, ylab="monthes", xlab="continue rate")
    par(new=F)
  }
  
  # calcurate predict interval and plot
  if (span=="predict") {
    d.lm.predict <- predict(d.lm, d.predict, interval="prediction")
    plot(monthes, d.lm.predict[,1], type="l", xlim=c(0,100), ylim=c(0,100), ylab="")
    par(new=T)
    plot(monthes, d.lm.predict[,2], type="l", xlim=c(0,100), ylim=c(0,100), lty=2,col="red",ylab="")
    par(new=T)
    plot(monthes, d.lm.predict[,3], type="l", xlim=c(0,100), ylim=c(0,100), lty=2,col="red",ylab="")
    par(new=T)
    plot(d$month, d$continue, type="p", xlim=c(0,100), ylim=c(0,100), lty=2, xlab="monthes", ylab="continue rate")
    par(new=F)
  }  
  return(d.lm.predict)
}

# execute function
predict.hoge.confidence <- predict_continue('hoge', 1000, 'confidence')
predict.hoge.predict <- predict_continue('hoge', 1000, 'predict')