Fig. 2

Runtimes needed for the assembling of samples with different sizes by three different methods. The grey line shows the time required for assembly with the bam file contains all the non-host sequences, called it BWA method; the blud line shows the time required for assembly with the sam file contains only the virus sequences detected by FastViromeExplorer, called it FastViromeExplorer + BWA method; and the orange line shows the time required for directly extracted the alignments from the sam output of FastViromeExplorer, called it FastViromeExplorer method. The x-axis is the number of virus reads detected by FastViromeExplorer. And the y-axis is the time used. As the figure shows, when the file size increase, the time used by Bwa method grows polynomially, but the time used by FastViromExplorer + BWA and FastViromeExplorer methods grow linearly