A-M baby

Task/Multiple-regression/R/multiple-regression-1.r

@@ -0,0 +1,6 @@
+## Wikipedia Data
+x <- c(1.47, 1.50, 1.52, 1.55, 1.57, 1.60, 1.63, 1.65, 1.68, 1.70, 1.73, 1.75, 1.78, 1.80, 1.83)
+}
+y <- c(52.21, 53.12, 54.48, 55.84, 57.20, 58.57, 59.93, 61.29, 63.11, 64.47, 66.28, 68.10, 69.92, 72.19, 74.46)
+
+lm( y ~ x + I(x^2))

Task/Multiple-regression/R/multiple-regression-2.r

@@ -0,0 +1,16 @@
+simpleMultipleReg <- function(formula) {
+
+    ## parse and evaluate the model formula
+    mf <- model.frame(formula)
+
+    ## create design matrix
+    X <- model.matrix(attr(mf, "terms"), mf)
+
+    ## create dependent variable
+    Y <- model.response(mf)
+
+    ## solve
+    solve(t(X) %*% X) %*% t(X) %*% Y
+}
+
+simpleMultipleReg(y ~ x + I(x^2))

Task/Multiple-regression/R/multiple-regression-3.r

@@ -0,0 +1 @@
+solve( crossprod(X), crossprod(X, Y))