Hi All,
I am illustrating a simple, two-way ANOVA using the following data and I'm
having difficulty in expressing the predicted values succinctly in R.
X- data.frame(read.table(textConnection(
Machine.1Machine.2Machine.3
53 61 51
Not sure if the following would qualify as elegant... It's easier to work
with a matrix instead of data frame:
x.mat - data.matrix(X)
xmean - mean(x.mat)
operator.eff - ave(x.mat, row(x.mat)) - xmean
machine.eff - ave(x.mat, col(x.mat)) - xmean
(predicted.x - xmean + operator.eff + machine.eff)
Try this:
Xm - as.matrix(X)
X.lm - lm(c(Xm) ~ factor(col(Xm)) + factor(row(Xm)))
sum(resid(X.lm)^2)
or if the idea was to do it without using lm try replacing
your calculation of X.predicted with this:
X.predicted -
outer(operator.adjustment, machine.adjustment, +) + mean(mean(X))
On
Here is one further idea:
Xm - as.matrix(X)
Xm. - scale(Xm, scale = FALSE)
Xm.. - t(scale(t(tmp), scale = FALSE))
sum(Xm..^2)
On 2/27/06, Gabor Grothendieck [EMAIL PROTECTED] wrote:
Try this:
Xm - as.matrix(X)
X.lm - lm(c(Xm) ~ factor(col(Xm)) + factor(row(Xm)))
sum(resid(X.lm)^2)
or if
