Figure 3

Leave-one-out crossvalidation error rate for k-nearest neighbour prediction. Leave-one-out cross validation error rates obtained from k-nearest neighbours (knn) prediction of KIR3DL1/3DS1 copy numbers from the R and θ signals of SNP rs592645. Each point shows the proportion of samples for which the knn predicted copy number did not match the qPCR call, averaged over ten multiply imputed qPCR call datasets (using the posterior probabilities from Figure 1). Error bars show the minimum and maximum error rates over the ten multiply imputed datasets. Knn was run in parallel for cases only, controls only and on all samples together. The minimum error rate is achieved for k=8 when the prediction uses both cases and controls.