Table 1 Variables of the breast-tissue dataset and their respective description

I0

Continuous

Impedivity (ohm) at zero frequency

PA500

Continuous

Phase angle at 500 KHz

HFS

Continuous

High-frequency slope of phase angle

DA

Continuous

Impedance distance between spectral ends

Area

Continuous

Area under spectrum

A/DA

Continuous

Area normalized by DA

Max IP

Continuous

IP maximum of the spectrum

DR

Continuous

Distance between I0 and real part of the maximum frequency point

P

Continuous

Length of the spectral curve

Class

Categorical

Carcinoma, fibro-adenoma, mastopathy, glandular, connective, adipose