a <- 2
b <- -3
sigSq <- 0.5
x <- runif(40)
y <- a + b * x + rnorm(40, sd = sqrt(sigSq))
(avgX <- mean(x))

## [1] 0.5334

write(avgX, "agX.txt")

plot(x, y)
abline(a, b, col = "purple")

plot of chunk unnamed-chunk-1

dev.print(pdf, "toylinePLot.pdf")

## pdf 
##   2