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.
data(haldport)A data frame with 13 observations on the following 6 variables.
p3caPositive Integer percentage of 3CaO.Al2O3 in the mixture.
p3csPositive Integer percentage of 3CaO.SiO2 in the mixture.
p4cafPositive Integer percentage of 4CaO.Al2O3.Fe2O3 in the mixture.
p2csPositive Integer percentage of 2CaO.SiO2 in the mixture.
otherPositive Integer percentage of other ingredients in the mixture.
heatHeat (cals/gm) evolved in setting, recorded to nearest tenth.
The (RXshrink) haldport data are identical to the (MASS) cement data except for variable names and inclusion of the "other" X-variable.
Hald A. Statistical Theory with Engineering Applications. 1952 (page 647.) New York; Wiley.