a <- 2
b <- -3
sigSq <- 0.5

set.seed(1234)
x <- runif(40)
y <- a + b * x + rnorm(40, sd = sqrt(sigSq))
(avgX <- mean(x))

## [1] 0.4584


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

plot of chunk unnamed-chunk-1


sessionInfo()

## R version 3.0.1 (2013-05-16)
## Platform: x86_64-w64-mingw32/x64 (64-bit)
## 
## locale:
## [1] LC_COLLATE=English_Canada.1252  LC_CTYPE=English_Canada.1252   
## [3] LC_MONETARY=English_Canada.1252 LC_NUMERIC=C                   
## [5] LC_TIME=English_Canada.1252    
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] knitr_1.4.1
## 
## loaded via a namespace (and not attached):
## [1] digest_0.6.3   evaluate_0.4.7 formatR_0.9    stringr_0.6.2 
## [5] tools_3.0.1