Reorder grid by polar angles

Description
To identofy structures in grid data varuíous functions like PCA and cluster analyis are available in the package. Another approach discussed by Raeithel (1998) is to reorder the grid matrix by their polar angles on the first two principal components from a data reduction technique (e. g. biplot). The function reorder2d reorders the grid according to the angles between the x-axis and the element (construct) vectors derived from a 2D biplot solution. This approach is apt to identify circumplex structures in data (cf. Acton & Revelle, 2004) indicated by the diagonal stripe in the display.

R-Code
To reorder the feixas2004 dataset by polar angles. reorder2d(feixas2004, color=c("white", "darkred"))



Literature

 * Acton, G. S., & Revelle, W. (2004). Evaluation of ten psychometric criteria for circumplex structure. Methods of Psychological Research - Online, 9(1), 1-27.
 * Raeithel, A. (1998). Kooperative Modellproduktion von Professionellen und Klienten – erläutert am Beispiel des Repertory Grid. In Selbstorganisation, Kooperation, Zeichenprozeß : Arbeiten zu einer kulturwissenschaftlichen, anwendungsbezogenen Psychologie (pp. 209-254). Opladen: Westdeutscher Verlag.