#NEWLINE# def neighbourOf( self , vertexIndex ) : #NEWLINE# #INDENT# '\n        Return an array of the indices of vertices than have an edge going to the input\n        vertex.\n\n        :param vertexIndex: the index of a vertex.\n        :type vertexIndex: :class:`int`\n\n        :returns: An array of the indices of all vertices with an edge towards the input vertex.\n        ' #NEWLINE# Parameter . checkIndex ( vertexIndex , 0 , self . vList . getNumVertices ( ) ) #NEWLINE# nonZeroInds = self . W [ : , vertexIndex ] . nonzero ( ) #NEWLINE# neighbours = nonZeroInds [ 0 ] #NEWLINE# return neighbours