RyR needs volumes of different compartments within the cell

V_myo = 21.5; # Intracellular volume
V_SR = V_myo*0.035; # SR volume
V_di = V_myo*0.0539; # diadic volume
    V = dict();
    V['V_myo'] = V_myo;
    V['V_SR'] = V_SR;
    V['V_di'] = V_di;


Currently, This is used only in RyR  module.
these volumes may be overwritten when replacing BG solver file.