Gasoline                package:nlme                R Documentation

Refinery yield of gasoline

Description:

     The 'Gasoline' data frame has 32 rows and 6 columns.

Format:

     This data frame contains the following columns:

     yield a numeric vector giving the percentage of crude oil
          converted to gasoline after distillation and fractionation

     endpoint a numeric vector giving the temperature (degrees F) at
          which all the gasoline is vaporized

     Sample an ordered factor giving the inferred crude oil sample
          number

     API a numeric vector giving the crude oil gravity (degrees API)

     vapor a numeric vector giving the vapor pressure of the crude oil
          (lbf/in^2)

     ASTM a numeric vector giving the crude oil 10% point ASTM-the
          temperature at which 10% of the crude oil has become vapor. 

Details:

     Prater (1955) provides data on crude oil properties and gasoline
     yields.  Atkinson (1985) uses these data to illustrate the use of
     diagnostics in multiple regression analysis.  Three of the
     covariates-\textsf{API}, \textsf{vapor}, and \textsf{ASTM}-measure
     characteristics of the crude oil used to produce the gasoline. 
     The other covariate - \textsf{endpoint}-is a characteristic of the
     refining process. Daniel and Wood (1980) notice that the
     covariates characterizing the crude oil occur in only ten distinct
     groups and conclude that the data represent responses measured on
     ten different crude oil samples.

Source:

     Prater, N. H. (1955), Estimate gasoline yields from crudes,
     _Petroleum Refiner_, *35* (5).

     Atkinson, A. C. (1985), _Plots, Transformations, and Regression_,
     Oxford Press, New York.

     Daniel, C. and Wood, F. S. (1980), _Fitting Equations to Data_,
     Wiley, New York

     Venables, W. N. and Ripley, B. D. (1999) _Modern Applied
     Statistics with S-PLUS (3rd ed)_, Springer, New York.

Examples:

     data(Gasoline)

