R: Steam Usage Data (Excerpt)

steamUse {robustbase} | R Documentation

## Steam Usage Data (Excerpt)

### Description

The monthly use of steam (`Steam`) in a factory may be modeled and described as function of the operating days per month (`Operating.Days`) and mean outside temperature per month (`Temperature`).

### Usage

    data("steamUse", package="robustbase")

### Format

A data frame with 25 observations on the following 9 variables.

`Steam`:

  regression response Y, the poinds of steam used monthly.

`fattyAcid`:

  pounds of Real Fatty Acid in storage per month.

`glycerine`:

  pounds of crude glycerine made.

`wind`:

  average wind velocity in miles per hour (a numeric vector).

`days`:

  an integer vector with number of days of that month, i.e., in 28..31.

`op.days`:

  the number of operating days for the given month (integer).

`freeze.d`:

  the number of days below 32 degrees Fahrenheit (= 0°C (C=Celsius) = freezing temperature of water).

`temperature`:

  a numeric vector of average outside temperature in Fahrenheit (F).

`startups`:

  the number of startups (of production in that month).

### Details

Nor further information is given in Draper and Smith, about the place and exacts years of the measurements, though some educated guesses should be possible, see the examples.

### Source

Data from Draper and Smith, 1st ed, 1966; appendix A.

A version of this has been used in teaching at SfS ETH Zurich, since at least 1996, https://stat.ethz.ch/Teaching/Datasets/NDK/dsteam.dat

The package aprean3 contains all data sets from the 3rd edition of Draper and Smith (1998), and this data set with variable names `x1 .. x10` (`x9` being `wind^2`, hence extraneous).

### References

Draper and Smith (1981) Applied Regression Analysis (2nd ed., p. 615 ff)

### Examples

    ## Not run:
    if(require("aprean3")) { # show how  'steamUse'  is related to 'dsa01a'
      stm <- dsa01a
      names(stm) <- c("Steam", "fattyAcid", "glycerine", "wind",
    		  "days", "op.days", "freeze.d",
    		  "temperature", "wind.2", "startups")
      ## prove that wind.2 is  wind^2, "traditionally" rounded to 1 digit:
      stopifnot(all.equal(floor(0.5 + 10*stm[,"wind"]^2)/10,
                          stm[,"wind.2"], tol = 1e-14))
      ## hence drop it
      steamUse <- stm[, names(stm) != "wind.2"]
    }

    ## End(Not run)
    data(steamUse)
    str(steamUse)
    ## Looking at this,
    cbind(M=rep_len(month.abb, 25), steamUse[,5:8, drop=FALSE])
    ## one will conjecture that these were 25 months, Jan--Jan in a row,
    ## starting in a leap year (perhaps 1960 ?).

    plot(steamUse)

    summary(fm1 <- lmrob(Steam ~ temperature + op.days, data=steamUse))
    ## diagnoses 2 outliers: month of July, maybe company-wide summer vacations

    ## KS2014 alone seems not robust enough:
    summary(fm.14 <- lmrob(Steam ~ temperature + op.days, data=steamUse,
             setting="KS2014"))
    pairs(Steam ~ temperature+op.days, steamUse)

[Package robustbase version 0.95-0 Index]