som (version 0.3-2)

qerror: quantization accuracy

Description

get the average distortion measure

Usage

qerror(obj, err.radius=1)

Arguments

obj

a `som' object

err.radius

radius used calculating qerror

Value

• An average of the following quantity (weighted distance measure) over all x in the sample, $$\sum ||x - m_i|| h_{ci}$$ where $h_{ci}$ is the neighbourhood kernel for the ith code.

Examples

foo <- som(matrix(rnorm(1000), 100), 2, 4)
qerror(foo, 3)