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diff --git a/man/massart97ex3.Rd b/man/massart97ex3.Rd index 1dabf90..2618709 100644 --- a/man/massart97ex3.Rd +++ b/man/massart97ex3.Rd @@ -10,6 +10,32 @@ A dataframe containing 6 levels of x values with 5 observations of y for each level. } +\examples{ +data(massart97ex3) +attach(massart97ex3) +yx <- split(y,x) +ybar <- sapply(yx,mean) +s <- round(sapply(yx,sd),digits=2) +w <- round(1/(s^2),digits=3) +weights <- w[factor(x)] +m <- lm(y ~ x,w=weights) +# The following concords with the book +inverse.predict(m, 15, ws = 1.67) +inverse.predict(m, 90, ws = 0.145) + +calplot(m) + +m0 <- lm(y ~ x) +lod(m0) +lod(m) + +# Now we want to take advantage of the lower weights at lower y values +m2 <- lm(y ~ x, w = 1/y) +# To get a reasonable weight for the lod, we need to estimate it and predict +# a y value for it +yhat.lod <- predict(m,data.frame(x = lod(m2))) +lod(m2,w=1/yhat.lod,k=3) +} \source{ Massart, L.M, Vandenginste, B.G.M., Buydens, L.M.C., De Jong, S., Lewi, P.J., Smeyers-Verbeke, J. (1997) Handbook of Chemometrics and Qualimetrics: Part A, p. 188 |