These functions provide tests for classes of generalized ellipsoids in the (U, D) representation, based on the numbers of positive, zero and infinite singular values in D.
They are included here mainly as computational definitions of the terms ‘bounded’ for an ellipsoid with finite extent, ‘fat’, for a bounded ellipsoid with non-empty interior, ‘flat’, for degenerate (singular) ellipsoids in \(R^p\) with empty interior.
Usage
isBounded(x, ...)
# S3 method for class 'gell'
isBounded(x, ...)
isFat(x, ...)
# S3 method for class 'gell'
isFat(x, ...)
isFlat(x, ...)
# S3 method for class 'gell'
isFlat(x, ...)
isUnbounded(x, ...)
# S3 method for class 'gell'
isUnbounded(x, ...)References
Friendly, M., Monette, G. and Fox, J. (2013). Elliptical Insights: Understanding Statistical Methods through Elliptical Geometry. Statistical Science, 28(1), 1-39.