Fig. 2.

Probabilistic graphical model representing the (a) JointSNVMix1 and (b) JointSNVMix2 model. Shaded nodes represent observed values or fixed values, while the values of unshaded nodes are learned using EM. Only the distributions for the normal are shown below, the tumour distributions are the same. We have defined f(q|a, z)=z[qa+(1 − q)(1 − a)]+0.5(1 − z) and g(r|z)=zr+(1 − z)(1 − r). Description of all random variables is given in Table 2.