It produces elliptical confidence regions when symmetrical or ordered symmetrical correspondence analysis is performed.
This function allows the analyst to superimpose confidence ellipses into a graphical display when the input parameter catype
of the main code CAvariants is equal to "CA", "SOCA" or "DOCA".
It is called internally from the main plot function plot.CAvariants.
It uses the function ellipse.
caellipse(Xtable, a1 = 1, a2 = 2, alpha = 0.05, cols = c(2, 4),
M = 2, cex = 0.8, cex.lab = 0.8,
mar = c(5, 4, 4, 2) + 0.1, prop = 0.8, Imass,
Jmass, a, b, g, fr, dmu, inertiapc, plottype = "biplot",
biptype = "row", pos = 2, arrow = TRUE, length = 0, graphy = TRUE, ell = TRUE)The two-way contingency table.
The dimension reflected along the horizontal axis.
The dimension reflected along the vertical axis.
The confidence level of the elliptical regions. By default, alpha = 0.05.
The graphical parameter for setting the colours of the points in the graphical displays.
The number of axes used when drawing ellypse. By default, M = 2. Its maximum value is equal to the rank of the data matrix.
The parameter for setting the size of character labels of points in graphical displays. By default, cex = 0.8.
The parameter for setting the size of character labels of axes in graphical displays. By default, cex.lab = 0.8.
The parameter for setting the size of the plotting area.
The scaling parameter for specifying the limits of the plotting area. By default, prop = 1.
The weight matrix of the row variable.
The weight matrix of the column variable.
The row principal or polynomial axes.
The column principal or polynomial axes.
The row coordinates.
The column coordinates.
The squared singular values or inertia of each axis.
The percentage of explained inertia.
The parameter that specifies the position of point symbols in the graphical displays. By default, pos = 2.
The parameter for specifying the type of plot. By default, plottype = "biplot".
The parameter for specifying the type of biplot. By default, biptype = "row".
The parameter used for diplaying arrows in biplot in correspondence of points in principal coordinates. By default, arrow=TRUE.
The parameter used for setting the length of the arrow end in biplot. By default, length=0.
The flag parameter used for diplaying ellipses when using plot.CAvariants and not displaying when using print.CAvariants function.
It is set as graphy = TRUE in plot.CAvariants and as graphy = FALSE in print.CAvariants.
The flag parameter used for displaying ellipse. By default, ell = TRUE.
Value of ellipse eccentricity. This is the distance between the ellipse center and either of its two foci, which can be thought of as a measure of how much the conic section deviates from being circular (when it is equal to zero then the region becomes circular).
Value of ellipse semi-axis 1 for each row and column points.
Value of ellipse semi-axis 2 for each row and column points.
Ellipse area for each row and column points.
P-value for each row and column points.
The output values of this function.
Beh EJ and Lombardo R 2014 Correspondence Analysis: Theory, Practice and New Strategies. John Wiley & Sons. Lombardo R Beh EJ 2016 Variants of Simple Correspondence Analysis. The R Journal, 8 (2), 167--184.