| % File src/library/datasets/man/mtcars.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2018 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{mtcars} |
| \docType{data} |
| \alias{mtcars} |
| \title{Motor Trend Car Road Tests} |
| \description{ |
| The data was extracted from the 1974 \emph{Motor Trend} US magazine, |
| and comprises fuel consumption and 10 aspects of |
| automobile design and performance for 32 automobiles (1973--74 |
| models). |
| } |
| \usage{mtcars} |
| \format{ |
| A data frame with 32 observations on 11 (numeric) variables. |
| \tabular{rll}{ |
| [, 1] \tab mpg \tab Miles/(US) gallon \cr |
| [, 2] \tab cyl \tab Number of cylinders \cr |
| [, 3] \tab disp \tab Displacement (cu.in.) \cr |
| [, 4] \tab hp \tab Gross horsepower \cr |
| [, 5] \tab drat \tab Rear axle ratio \cr |
| [, 6] \tab wt \tab Weight (1000 lbs) \cr |
| [, 7] \tab qsec \tab 1/4 mile time \cr |
| [, 8] \tab vs \tab Engine (0 = V-shaped, 1 = straight) \cr |
| [, 9] \tab am \tab Transmission (0 = automatic, 1 = manual) \cr |
| [,10] \tab gear \tab Number of forward gears \cr |
| [,11] \tab carb \tab Number of carburetors |
| } |
| } |
| \source{ |
| Henderson and Velleman (1981), |
| Building multiple regression models interactively. |
| \emph{Biometrics}, \bold{37}, 391--411. |
| } |
| \note{ |
| Henderson and Velleman (1981) comment in a footnote to Table 1: |
| \sQuote{Hocking [original transcriber]'s noncrucial coding of the |
| Mazda's rotary engine as a straight six-cylinder engine and the |
| Porsche's flat engine as a V engine, as well as the inclusion of the |
| diesel Mercedes 240D, have been retained to enable direct comparisons |
| to be made with previous analyses.} |
| } |
| \examples{ |
| require(graphics) |
| pairs(mtcars, main = "mtcars data", gap = 1/4) |
| coplot(mpg ~ disp | as.factor(cyl), data = mtcars, |
| panel = panel.smooth, rows = 1) |
| ## possibly more meaningful, e.g., for summary() or bivariate plots: |
| mtcars2 <- within(mtcars, { |
| vs <- factor(vs, labels = c("V", "S")) |
| am <- factor(am, labels = c("automatic", "manual")) |
| cyl <- ordered(cyl) |
| gear <- ordered(gear) |
| carb <- ordered(carb) |
| }) |
| summary(mtcars2) |
| } |
| \keyword{datasets} |