Fraction function

Selection of a fraction of the data

Selects a percentage of the data eliminating the observations with higher Mahalanobis distances to the center.

Fraction(data, confidence = 1)

Arguments

• data: Two dimensional data set
• confidence: Percentage to retain. (0-1)

Details

The function is used to select a fraction of the data to be plotted for example when clusters are used. The function eliminates the extreme values.

Returns

An object of class fraction with the following fields - data: The originaldata

• fraction: The selected data

• confidence: The percentage selected

References

Meulman, J. J., & Heiser, W. J. (1983). The display of bootstrap solutions in multidimensional scaling. Murray Hill, NJ: Bell Laboratories.

Linting, M., Meulman, J. J., Groenen, P. J., & Van der Kooij, A. J. (2007). Stability of nonlinear principal components analysis: An empirical study using the balanced bootstrap. Psychological Methods, 12(3), 359.

Author(s)

Jose Luis Vicente Villardon

See Also

ConcEllipse, AddCluster2Biplot

Examples

a=matrix(runif(50), 25,2)
a2=Fraction(a, 0.7)