def topDownCompute(self, topDownIn=None):
output = numpy.zeros(self.numberOfColumns())<EOL>columns = [self.columnForCell(idx) for idx in self.getPredictiveCells()]<EOL>output[columns] = <NUM_LIT:1><EOL>return output<EOL>
(From `backtracking_tm.py`)
Top-down compute - generate expected input given output of the TM

@param topDownIn top down input from the level above us

@returns best estimate of the TM input that would have generated bottomUpOut.