ethanol {lattice} | R Documentation

## Engine exhaust fumes from burning ethanol

### Description

Ethanol fuel was burned in a single-cylinder engine. For various settings of the engine compression and equivalence ratio, the emissions of nitrogen oxides were recorded.

### Usage

    ethanol

### Format

A data frame with 88 observations on the following 3 variables.

NOx
  Concentration of nitrogen oxides (NO and NO2) in micrograms/J.
C
  Compression ratio of the engine.
E
  Equivalence ratio–a measure of the richness of the air and ethanol fuel mixture.

### Author(s)

Documentation contributed by Kevin Wright.

### Source

Brinkman, N.D. (1981) Ethanol Fuel—A Single-Cylinder Engine Study of Efficiency and Exhaust Emissions. SAE transactions, 90, 1410–1424.

### References

Cleveland, William S. (1993). Visualizing Data. Hobart Press, Summit, New Jersey.

### Examples

    ## Constructing panel functions on the fly
    EE <- equal.count(ethanol$E, number=9, overlap=1/4)
    xyplot(NOx ~ C | EE, data = ethanol,
           prepanel = function(x, y) prepanel.loess(x, y, span = 1),
           xlab = "Compression ratio", ylab = "NOx (micrograms/J)",
           panel = function(x, y) {
               panel.grid(h=-1, v= 2)
               panel.xyplot(x, y)
               panel.loess(x,y, span=1)
           },
           aspect = "xy")

    # Wireframe loess surface fit.  See Figure 4.61 from Cleveland.
    require(stats)
    with(ethanol, {
      eth.lo <- loess(NOx ~ C * E, span = 1/3, parametric = "C",
                            drop.square = "C", family="symmetric")
      eth.marginal <- list(C = seq(min(C), max(C), length = 25),
                                 E = seq(min(E), max(E), length = 25))
      eth.grid <- expand.grid(eth.marginal)
      eth.fit <- predict(eth.lo, eth.grid)
      wireframe(eth.fit ~ eth.grid$C * eth.grid$E,
                shade=TRUE,
                screen = list(z = 40, x = -60, y=0),
                distance = .1,
                xlab = "C", ylab = "E", zlab = "NOx")
    })

[Package lattice version 0.11-8 Index]