On this Picostat.com statistics page, you will find information about the wood data set which pertains to Modified Data on Wood Specific Gravity. The wood data set is found in the robustbase R package. Try to load the wood data set in R by issuing the following command at the console data("wood"). This may load the data into a variable called wood. If R says the wood data set is not found, you can try installing the package by issuing this command install.packages("robustbase") and then attempt to reload the data with library("robustbase") followed by data("wood"). Perhaps strangley, if R gives you no output after entering a command, it means the command succeeded. If it succeeded you can see the data by typing wood at the command-line which should display the entire dataset.
If you need to download R, you can go to the R project website. You can download a CSV (comma separated values) version of the wood R data set. The size of this file is about 761 bytes.
Modified Data on Wood Specific Gravity
The original data are from Draper and Smith (1966) and
were used to determine the influence of anatomical factors on wood
specific gravity, with five explanatory variables and an
intercept. These data were contaminated by replacing a few
observations with outliers.
A data frame with 20 observations on the following 6 variables.
- x1, x2, x3, x4, x5
explanatory “anatomical” wood
wood specific gravity, the target variable.
Draper and Smith (1966, p.227)
Peter J. Rousseeuw and Annick M. Leroy (1987)
Robust Regression and Outlier Detection Wiley, p.243, table 8.
summary( lm.wood <- lm(y ~ ., data = wood))
summary(rlm.wood <- MASS::rlm(y ~ ., data = wood))
summary(lts.wood <- ltsReg(y ~ ., data = wood))wood.x <- as.matrix(wood)[,1:5]
c_wood <- covMcd(wood.x)
Dataset imported from https://www.r-project.org.