haldport: Portland Cement data of Hald(1952)

In RXshrink: Maximum Likelihood Shrinkage using Generalized Ridge or Least Angle Regression

Portland Cement data of Hald(1952)

Description

Heat evolved during setting of 13 cement mixtures of four (or five) ingredients. The first four ingredient percentages appear to be "rounded down" to a full integer. The fifth integer percentage of "other" material assures that the five percentages sum to exactly 100%. However, the "centered" X-matrix resulting from inclusion of all five ingredients would then be Singular (rank=4). In other words, regressing any y-Outcome on only the first four X-variables yields an "ill-conditioned" model that, while having numerical "full rank"=4, actually suffers a effective "rank deficiency" of at least mcal = 1.

Usage

data(haldport)

Format

A data frame with 13 observations on the following 6 variables.

p3ca

Positive Integer percentage of 3CaO.Al2O3 [tricalcium aluminate] in the mixture.

p3cs

Positive Integer percentage of 3CaO.SiO2 [tricalcium silicate] in the mixture.

p4caf

Positive Integer percentage of 4CaO.Al2O3.Fe2O3 [tetracalcium aluminoferrite] in the mixture.

p2cs

Positive Integer percentage of 2CaO.SiO2 [dicalcium silicate] in the mixture.

other

Positive Integer percentage of other ingredients in the mixture.

heat

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

Details

The (RXshrink) haldport data are identical to the (MASS) cement data except for variable names and inclusion of the "other" X-variable.

Source

Woods H, Steinour HH, Starke HR. "Effect of composition of Portland cement on heat evolved during hardening. Industrial Engineering and Chemistry 1932; 24: 1207-1214.

References

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

Obenchain RL. (2022) Efficient Generalized Ridge Regression. Open Statistics 3: 1-18. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1515/stat-2022-0108")}

RXshrink documentation built on Aug. 8, 2023, 1:09 a.m.