Cobiveco: Consistent biventricular coordinates for precise and intuitive description of position in the heart – with MATLAB implementation

•A consistent biventricular coordinate system with symmetric coordinate directions in both ventricles is proposed.•A systematic comparison of PDE-based approaches was performed to obtain coordinates that change linearly in space.•A novel one-way mapping error was introduced to assess the consistency of coordinates across different geometries.•Evaluation of mapping and linearity errors on 36 geometries showed a 4-fold improvement compared to a state-of-the-art method.•An open-source implementation in MATLAB is available.