plot.princals function

Plot Methods for Princals

Various plotting options for objects of class "princals".

## S3 method for class 'princals'
plot(x, plot.type = "loadplot", plot.dim = c(1, 2), var.subset = "all", 
col.scores = "black", col.loadings = "black", col.lines = "black", cex.scores = 0.8, 
cex.loadings = 0.8, stepvec = NA, max.plot.array = NA, expand = 1, 
asp = 1, main, xlab, ylab, xlim, ylim, ...)

Arguments

• x: Object of class "princals"
• plot.type: String indicating which type of plot to be produced: "biplot", "loadplot", "screeplot", "transplot", "objplot". See details.
• plot.dim: Vector with dimensions to be plotted.
• var.subset: Numeric vector for subsetting variables to be plotted. If missing, all variables are taken into account. Ignored for non separate variable plots.
• col.scores: Color object scores.
• col.loadings: Color loading vectors.
• col.lines: Line colors for transformation and scree plot.
• cex.scores: Size object scores.
• cex.loadings: Size loading labels.
• asp: Aspect ratio
• stepvec: Vector whether step function should be plotted (see details).
• max.plot.array: Number of panels in transformation plot.
• expand: Expansion factor for loadings in biplot.
• main: Plot title.
• type: Type of points/lines to be plotted.
• xlab: Label of x-axis.
• ylab: Label of y-axis.
• xlim: Limits for x-axis.
• ylim: Limits for y-axis.
• ...: Further plot arguments passed: see plot

Details

Plot description:

• Biplot (plot.type = "biplot"): Biplot with the object scores and the loadings. It uses biplot.default from stats internally (see corresponding help file for additional arguments)

• Transformation plot (plot.type = "transplot"): Plots the original scale against the transformed scale (first dimension) for each variable separately.

• Loadings plot (plot.type = "loadplot"): Plots the loadings of the variables and connects them with the origin.

• Scree plot (plot.type = "screeplot"): Produces a scree plot based on the eigenvalues.

• Plotting the object scores (factor scores; plot.type = "objplot").

For transformation plots only: If stepvec = NA, the function tries to figure out which variable should be plotted as step function. Alternatively, a boolean vector (with length number of variables) can be specified (TRUE step function, FALSE smooth function).

Examples

## Ordinal PCA
ABC6 <- ABC[,6:11]
fitord <- princals(ABC6, ndim = 3)  ## 3D princals solution

## transformation plot
plot(fitord, plot.type = "transplot", var.subset = 1:4, lwd = 2, col.lines = "coral")

## loadings plot
plot(fitord, "loadplot", main = "Loadings Plot ABC Data")

## biplot
plot(fitord, "biplot", main = "Biplot ABC Data", cex.scores = 0.5)  
plot(fitord, "biplot", main = "Biplot ABC Data")
plot(fitord, "biplot", main = "Biplot ABC Data", plot.dim = c(2,3))

## scree plot
plot(fitord, "screeplot")  

## object scores
plot(fitord, "objplot", cex.scores = 0.6)

## PCA for mixed scale levels