This document allows you to build vector diagrams of voltages and currents online. Instructions are given here. An algorithm for constructing vector diagrams for electrical circuits is given here.
Also you can build vector diagram for analog signal from oscillogram in COMTRADE format.
Set the voltage and current vectors in polar form:
VA = ∠°
VB = ∠°
VC = ∠°
IA = ∠°
IB = ∠°
IC = ∠°
V I
Base vector: