LenthPlot {BsMD} | R Documentation |

## Lenth's Plot of Effects

### Description

Plot of the factor effects with significance levels based on robust estimation of contrast standard errors.

### Usage

```
LenthPlot(obj, alpha = 0.05, plt = TRUE, limits = TRUE,
xlab = "factors", ylab = "effects", faclab = NULL, cex.fac = par("cex.lab"),
cex.axis=par("cex.axis"), adj = 1, ...)
```

### Arguments

`obj` |
object of class |

`alpha` |
numeric. Significance level used for the |

`plt` |
logical. If |

`limits` |
logical. If |

`xlab` |
character string. Used to label the x-axis. "factors" as default. |

`ylab` |
character string. Used to label the y-axis. "effects" as default. |

`faclab` |
list with components |

`cex.fac` |
numeric. Character size used for the factor labels. |

`cex.axis` |
numeric. Character size used for the axis. |

`adj` |
numeric between 0 and 1. Determines where to place the
"ME" (margin of error) and the "SME" (simultaneous margin of error) labels
(character size of 0.9* |

`...` |
extra parameters passed to |

### Details

If `obj`

is of class `lm`

, `2*coef(obj)`

is used as factor
effect with the intercept term removed. Otherwise, `obj`

should be a
vector with the factor effects. Robust estimate of the contrasts standard
error is used to calculate *marginal* (ME) and *simultaneous margin
of error* (SME) for the provided significance (`1 - alpha`

) level.
See Lenth(1989). Spikes are used to display the factor effects.
If `faclab`

is `NULL`

, factors are labelled with the effects or
coefficient names. Otherwise, those `faclab\$idx`

factors are labelled
as `faclab\$lab`

. The rest of the factors are blanked.

### Value

The function is called mainly for its side effect. It returns a vector with the value of alpha used, the estimated PSE, ME and SME.

### Author(s)

Ernesto Barrios. Extension provided by Kjetil Kjernsmo (2013).

### References

Lenth, R. V. (1989).
"Quick and Easy Analysis of Unreplicated Factorials".
*Technometrics* Vol. 31, No. 4. pp. 469–473.

### See Also

`DanielPlot`

, `BsProb`

and `plot.BsProb`

### Examples

```
### Tensile Strength Experiment. Taguchi and Wu. 1980
library(BsMD)
# Data
data(BM86.data,package="BsMD") # Design matrix and responses
print(BM86.data) # from Box and Meyer (1986)
# Model Fitting. Box and Meyer (1986) example 2.
tensileStrength.lm <- lm(y2 ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 +
X10 + X11 + X12 + X13 + X14 + X15, data = BM86.data)
print(coef(tensileStrength.lm)) # Model coefficients
par(mfrow=c(1,2),pty="s")
DanielPlot(tensileStrength.lm, main = "Daniel Plot")
LenthPlot(tensileStrength.lm, main = "Lenth's Plot")
```

*BsMD*version 2023.920 Index]