## Homework 2 due tomorrow
## Homework 3 on web, due on Friday
## Splines Stuff


x <- runif(500,0,10)
x <- x[order(x)]
y.perf <- sin(x)
y <- sin(x) + rnorm(500,0,.5)
plot(x,y, pch=16, cex=1.5)


mod1 <- lm(y ~ bs(x, knots=c(1.5, 4.7, 7.8), degree=3))
plot(effect("bs(x, knots=c(1.5, 4.7, 7.8), degree=3)", mod1, default.levels=100))

mod2 <- lm(y ~ bs(x, knots=c(3.25, 6.2), degree=3))
plot(effect("bs(x, knots=c(3.25, 6.2), degree=3)", mod2, default.levels=100))

k <- quantile(x, probs=c(.25,.75))
mod3 <- lm(y ~ bs(x, knots=k, degree=3))
plot(effect("bs(x, knots=k, degree=3)", mod3, default.levels=100))

pred.data <- data.frame(x=seq(0.1,9.9,length=100))

pred1 <- predict(mod1, newdata=pred.data)
pred2 <- predict(mod2, newdata=pred.data)
pred3 <- predict(mod3, newdata=pred.data)

plot(range(x), range(c(pred1, pred2, pred3)), type="n")
plot(range(x), range(y), type="n")
points(x,y, col="gray50")

lines(pred.data$x, pred1, lty=1, lwd=2)
lines(pred.data$x, pred2, lty=2, lwd=2)
lines(pred.data$x, pred3, lty=3, lwd=2)


data <- read.dta("../Lecture 6/jacob.dta")

knots <- quantile(data$perotvote, probs=c(.25,.5,.75))
mod3 <- lm(chal_vote ~ bs(perotvote, knots=knots, degree=3) + chal_spend, data=data)
plot(effect("bs(perotvote, knots=c(15.47158, 19.91128, 23.40235 ), degree=3)", mod3, default.levels=100))

mod3 <- lm(chal_vote ~ bs(perotvote, knots=c(15.47158, 19.91128, 23.40235 ), degree=3) + chal_spend, data=data)

mod3 <- lm(chal_vote ~ bs(perotvote, df=4, degree=3) + chal_spend, data=data)
plot(effect("bs(perotvote, df=4, degree=3)", mod3, default.levels=100))


mod3 <- lm(chal_vote ~ bs(perotvote, knots=knots, degree=3) + chal_spend, data=data)
pred.data <- data.frame(
	perotvote = seq(min(data$perotvote), max(data$perotvote), length=100), 
	chal_spend = mean(data$chal_spend))

preds <- as.data.frame(predict(mod3, newdata=pred.data, interval="confidence"))

xyplot(preds$fit ~ pred.data$perotvote, type="l", 
	ylim=c(min(preds$lwr), max(preds$upr)), 
	xlab="Perot Vote", ylab="Challenger Vote", 
	panel=function(x,y){
		panel.lines(x,y, lty=1, col="black")
		panel.lines(x, preds$lwr, lty=2, col="red")
		panel.lines(x, preds$upr, lty=2, col="red")
		panel.rug(data$perotvote, col="black")
	}
)