Dot product kernel. The outputs of dot product kernel as functions of the angles between vectors. Four functions are depicted in solid-blue, long-dashed-red, short-dashed-green and dotted-purple curves, corresponding to the cases where the product of the norms of the and vectors is equal to 0.5, 1, 2 and 3 respectively.
Land et al. BMC Systems Biology 2011 5(Suppl 3):S13 doi:10.1186/1752-0509-5-S3-S13