cplex 註記：rhs 加 float

    def _add_constraint_3(self):
        sum = 0
        for i in range(self.N):
            for j in range(self.N):
                sum = sum + self.v_x[i]*self.v_x[j]*self.Sigma_1[i][j]
        sum = round(sum, 2)
        print(sum)
        ind1 = ['s','w']
        ind2 = ['s','z']
        val = [1.0, -4]
        Q = cplex.SparseTriple(ind1,ind2,val)
        self.subProb.quadratic_constraints.add(quad_expr=Q, sense='L', rhs=(-sum), name="Q")
        print('constraint 3:'+str(sum)+'+s^2 <=4wz')

報錯

  self.subProb.quadratic_constraints.add(quad_expr=Q, sense='L', rhs=(-sum), name="Q")
  File "D:\ProgramFiles\python3.6.5\lib\site-packages\cplex\_internal\_subinterfaces.py", line 2654, in add
    lin_expr, quad_expr, sense, rhs, name)
  File "D:\ProgramFiles\python3.6.5\lib\site-packages\cplex\_internal\_baseinterface.py", line 50, in _add_single
    addfun(*args, **kwargs)
  File "D:\ProgramFiles\python3.6.5\lib\site-packages\cplex\_internal\_subinterfaces.py", line 2603, in _add
    self._env._apienc)
  File "D:\ProgramFiles\python3.6.5\lib\site-packages\cplex\_internal\_procedural.py", line 1474, in addqconstr
    cpx_decode_noop3(name, enc))
TypeError: in method 'CPXXaddqconstr', argument 5 of type 'double'

解決：入參 rhs 需要爲 double 類型，在入參前面加個float 即可

self.subProb.quadratic_constraints.add(quad_expr=Q, sense='L', rhs=float(-sum), name="Q")