<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def encodeDeltas(self, dx,dy):
 """Return the SDR for dx,dy"""

    dxe = self.dxEncoder.encode(dx)
    dye = self.dyEncoder.encode(dy)
    ex = numpy.outer(dxe,dye)
    return ex.flatten().nonzero()[0]