R: Validation Plots

validationplot {pls} | R Documentation

## Validation Plots

### Description

Functions to plot validation statistics, such as RMSEP or R^2, as a function of the number of components.

### Usage

    validationplot(object, val.type = c("RMSEP", "MSEP", "R2"), estimate,
                   newdata, ncomp, comps, intercept, ...)
    ## S3 method for class 'mvrVal'
    plot(x, nCols, nRows, type = "l", lty = 1:nEst,
         lwd = par("lwd"), pch = 1:nEst, cex = 1, col = 1:nEst, legendpos,
         xlab = "number of components", ylab = x$type, main,
         ask = nRows * nCols < nResp && dev.interactive(), ...)

### Arguments

`object` | an `mvr` object.
`val.type` | character. What type of validation statistic to plot.
`estimate` | character. Which estimates of the statistic to calculate. See `RMSEP`.
`newdata` | data frame. Optional new data used to calculate statistic.
`ncomp, comps` | integer vector. The model sizes to compute the statistic for. See `RMSEP`.
`intercept` | logical. Whether estimates for a model with zero components should be calculated as well.
`x` | an `mvrVal` object. Usually the result of a `RMSEP`, `MSEP` or `R2` call.
`nCols, nRows` | integers. The number of coloumns and rows the plots will be laid out in. If not specified, `plot.mvrVal` tries to be intelligent.
`type` | character. What type of plots to create. Defaults to `"l"` (lines). Alternative types include `"p"` (points) and `"b"` (both). See `plot` for a complete list of types.
`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. If present, a legend is drawn at the given position. The position can be specified symbolically (e.g., `legendpos = "topright"`). This requires R >= 2.1.0. Alternatively, the position can be specified explicitly (`legendpos = t(c(x,y))`) or interactively (`legendpos = locator()`). This only works well for plots of single-response models.
`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.
`main` | optional main title for the plot. See Details.
`ask` | logical. Whether to ask the user before each page of a plot.
`...` | Further arguments sent to underlying plot functions.

### Details

`validationplot` calls the proper validation function (currently `MSEP`, `RMSEP` or `R2`) and plots the results with `plot.mvrVal`. `validationplot` can be called through the `mvr` plot method, by specifying `plottype = "validation"`.

`plot.mvrVal` creates one plot for each response variable in the model, laid out in a rectangle. It uses `matplot` for performing the actual plotting. If `legendpos` is given, a legend is drawn at the given position.

The argument `main` can be used to specify the main title of the plot. It is handled in a non-standard way. If there is only on (sub) plot, `main` will be used as the main title of the plot. If there is more than one (sub) plot, however, the presence of `main` will produce a corresponding ‘global’ title on the page. Any graphical parametres, e.g., `cex.main`, supplied to `coefplot` will only affect the ‘ordinary’ plot titles, not the ‘global’ one. Its appearance can be changed by setting the parameters with `par`, which will affect both titles. (To have different settings for the two titles, one can override the `par` settings with arguments to the plot function.)

### Note

`legend` has many options. If you want greater control over the appearance of the legend, omit the `legendpos` argument and call `legend` manually.

### Author(s)

Ron Wehrens and Bjørn-Helge Mevik

### See Also

`mvr`, `plot.mvr`, `RMSEP`, `MSEP`, `R2`, `matplot`, `legend`

### Examples

    data(oliveoil)
    mod <- plsr(sensory ~ chemical, data = oliveoil, validation = "LOO")
    ## Not run:
    ## These three are equivalent:
    validationplot(mod, estimate = "all")
    plot(mod, "validation", estimate = "all")
    plot(RMSEP(mod, estimate = "all"))
    ## Plot R2:
    plot(mod, "validation", val.type = "R2")
    ## Plot R2, with a legend:
    plot(mod, "validation", val.type = "MSEP", legendpos = "top") # R >= 2.1.0

    ## End(Not run)

[Package pls version 2.7-0 Index]