Hald: Portland Cement benchmark of Hald(1952)

In lmridge: Linear Ridge Regression with Ridge Penalty and Ridge Statistics

Portland Cement benchmark of Hald(1952)

Description

Heat evolved during setting of 13 cement mixtures of four basic ingredients. Each ingredient percentage appears to be rounded down to a full integer. The sum of the four mixture percentages varies from a maximum of 99% to a minimum of 95%. If all four regressor X-variables always summed to 100%, the centered X-matrix would then be of rank only 3. Thus, the regression of heat on four X-percentages is ill-conditioned, with an approximate rank deficiency of MCAL = 1.

Usage

data(Hald)

Format

A data frame with 13 observations on the following 5 variables.

X1

p3ca: Integer percentage of 3CaO.Al2O3 in the mixture.

X2

p3cs: Integer percentage of 3CaO.SiO2 in the mixture.

X3

p4caf: Integer percentage of 4CaO.Al2O3.Fe2O3 in the mixture.

X4

p2cs: Integer percentage of 2CaO.SiO2 in the mixture.

y

hear: Heat (cals/gm) evolved in setting, recorded to nearest tenth.

Details

The (lmridge) Hald data are identical to the (MASS) cement data except for variable names.

Source

Woods, H., Steinour, H.H. and Starke, H.R. (1932). Effect of Composition of Portland Cement on Heat Evolved During Hardening. Industrial Engineering and Chemistry 24: 1207–1214.

References

Hald, A. (1952). Statistical Theory with Engineering Applications.(page 647.) New York; Wiley.

lmridge documentation built on Jan. 15, 2023, 5:06 p.m.