Hello,
the following lines
m <- matrix(c(1,1,9,1,2,6,1,3,7,2,1,4,2,2,5,2,3,1,3,1,2,3,2,-1,3,3,-2), 9,
3, byrow = TRUE, dimnames=list(NULL, cbind('A','B','Y')))
md <- as.data.frame(m)
md$A <- as.factor(md$A)
md$B <- as.factor(md$B)
mm <- model.matrix(Y~A+B+A:B, data=md)
produce
> mm
(Interce
I have the following data set
> data
A B X1 X2 Y
1 A1 B1 1.1 2.9 1.2
2 A1 B2 1.0 3.2 2.3
3 A2 B1 1.0 3.3 1.6
4 A2 B2 0.5 2.6 3.1
> sapply(data, class)
A BX1X2 Y
"factor" "factor" "numeric" "numeric" "numeric"
I'd like to set a specific type of
thank you all.
i have deliberately chosen matinv (although obviously
an outdated version) because it uses the sweep operator.
i know of other methods to calculate generalized inverses.
however, it is also true that the sweep operator is capable of
computing g2 generalized inverses.
The ginv re
i am trying to use matinv from the Design package
to compute the generalized inverse of the normal equations
of a 3x3 design via the sweep operator.
That is, for the linear model
y = ยต + x1 + x2 + x1*x2
where x1, x2 are 3-level factors and dummy coding is being used
the matrix to be inverted i
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