Fixed 'RuntimeWarning: invalid value encountered in divide' warning
Fixed 'RuntimeWarning: invalid value encountered in divide' warning

simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs