pls (version 1.2-1)

coefplot: Plot Regression Coefficients of PLSR and PCR models

Description

Function to plot the regression coefficients of an mvr object.

Usage

coefplot(object, ncomp = object$ncomp, separate = FALSE, cumulative = TRUE,
         intercept = FALSE, nCols, nRows, varnames = FALSE, type = "l",
         lty = 1:nLines, lwd = NULL, pch = 1:nLines, cex = NULL,
         col = 1:nLines, legendpos, xlab = "variable",
         ylab = "regression coefficient", ...)

Arguments

object

an mvr object. The fitted model.

ncomp

integer vector. The number of components to include. If length(ncomp) > 1, coefficients for each model size is plotted.

separate

logical. If TRUE, coefficients for different model sizes are blotted in separate plots.

cumulative

logical. Whether cumulative (the default) or individual coefficients for each component should be plotted. See coef.mvr for details.

intercept

logical. Whether coefficients for the intercept should be plotted. Ignored if cumulative = FALSE. Defaults to FALSE. See coef.mvr for details.

nCols, nRows

integer. The number of coloumns and rows the plots will be laid out in. If not specified, coefplot tries to be intelligent.

varnames

logical. If TRUE, the $x$ axis tick marks are labelled with the variable names.

type

character. What type of plot to make. Defaults to "l" (lines). Alternative types include "p" (points) and "b" (both). See plot for a complete list of type

lty

vector of line types (recycled as neccessary). Line types can be specified as integers or character strings (see par for the details).

lwd

vector of positive numbers (recycled as neccessary), giving the width of the lines.

pch

plot character. A character string or a vector of single characters or integers (recycled as neccessary). See points for all alternatives.

cex

numeric vector of character expansion sizes (recycled as neccessary) for the plotted symbols.

col

character or integer vector of colors for plotted lines and symbols (recycled as neccessary). See par for the details.

legendpos

Legend position. Optional. Ignored if separate is TRUE. If present, a legend is drawn at the given position. The position can be specified symbolically (e.g., legendpos = "topright"). This requires

xlab,ylab

titles for $x$ and $y$ axes. Typically character strings, but can be expressions (e.g., expression(R^2) or lists. See title for details.

...

Further arguments sent to the underlying plot functions.

encoding

latin1

Details

coefplot handles multiple responses by making one plot for each response. If separate is TRUE, separate plots are made for each combination of model size and response. The plots are laid out in a rectangular fashion.

If legendpos is given, a legend is drawn at the given position (unless separate is TRUE).

If varnames is TRUE, the $x$ axis tick marks are labelled with the regressor variable names. Hint: If there is not enough room for all names to be displayed, try reducing the text size by giving the argument cex.axis with a value less than 1, or try printing the names vertically by giving the argument las = 3.

The function can also be called through the mvr plot method by specifying plottype = "coefficients".

See Also

mvr, plot.mvr, coef.mvr, plot, legend

Examples

data(NIR)
mod.nir <- plsr(y ~ X, ncomp = 8, data = NIR)
coefplot(mod.nir, ncomp = 1:6)
plot(mod.nir, plottype = "coefficients", ncomp = 1:6) # Equivalent to the previous
## Plot with legend:
coefplot(mod.nir, ncom = 1:6, legendpos = "bottomright")

data(sensory)
mod.sens <- plsr(Quality ~ Panel, ncomp = 4, data = sensory)
coefplot(mod.sens, ncomp = 2:4, separate = TRUE)