ca.procrustes.curve {lakhesis}

Seriate Using Reference Curve

Description

Obtain a ranking of row and column scores projected onto a reference curve of an ideal seriation (row and column scores are ranked separately). Scores of correspondence analysis have been fit to those produced by reference matrix contain an ideal seriation using a Procrustes method, projecting them. Rotation is determined by minimizing Euclidean distance from each row score to the nearest reference row score. Correspondence analysis is performed using the ca package (Nenadic and Greenacre 2007).

Usage

ca.procrustes.curve(obj, resolution = 10000)

Arguments

obj

An incidence matrix of size n x k.

resolution

Number of samples to use for plotting points along polynomial curve (default is 10000).

Value

A data frame of the following:.

• ⁠Procrustes1,Procrustes2⁠ The location of the point on the biplot after fitting.

• CurveIndex The orthogonal projection of the point onto the reference curve, given as the index of the point sampled along y = \beta_2 x^2 + \beta_0.

• Distance The squared Euclidean distance of the point to the nearest point on the reference curve.

• Rank The ranking of the row or column, a range of ⁠1:nrow`` and ⁠1:ncol“.

• Type Either row or col.

• sel Data frame column used in shiny app to indicate whether point is selected in biplot/curve projection.

References

Nenadic O, Greenacre MJ (2007). “Correspondence Analysis in R, with Two- and Three-dimensional Graphics: The ca Package.” Journal of Statistical Software, 20, 1–13. doi:10.18637/jss.v020.i03.

Examples

data("quattrofontanili")
ca.procrustes.curve(quattrofontanili)