Fig. 2

Estimation of tumour sample purity for region 2 of the tumour. The parameter ξ was calculated at all eligible loci across the genome and the empirical distribution is plotted here. The sample purity is equal to the maximum value of ξ which is interpreted to occur at the rightmost maximum at ξ=0.53. The distribution of ξ is ‘smoothed’ due to the fact that at each locus ξ is estimated from a finite sample of sequencing reads