Comparison of the NRMSEs of various method s. Comparison of the NRMSEs of LLSimpute, kNN, BPCA, and RLSP imputation methods on ELU data set with the 5% missing rate. BPCA results are shown on the y-axis. The x-axis represents the value of k (selected similar genes). When k is close to sample size (N), LLSimpute has a high peak. Thus we truncated it in the graph. RLSP method demonstrated a better result than other methods.