我正在尝试使用cvxpy(因此涉及到cvxopt)对具有28个节点和37条线路的相对简单网络进行最优功率流建模,但是出现了“Rank(A) < p或Rank([G; A])< n”错误。
当我查看"/Library/Python/2.7/site-packages/cvxopt/coneprog.py"的第687行时,实际上是在处理算术错误。
(使用相同的代码,我可以为一个更简单的4节点和4条线路的网络找到最优解。)
我已经非常仔细地检查了约束条件是否不一致(使用我在Stack Overflow上回答这个问题时的答案: Check constraints are ok in cvxpy with actual values )
以下是错误回溯:
File "main.py", line 201, in test_simple_optimisation
p, bids, offers = optimize_flow(bids, offers, lines, nodes, injections_from_schedule, shift_factors, admittance.T)
File "main.py", line 143, in optimize_flow
p.solve()
File "build/bdist.macosx-10.8-intel/egg/cvxpy/programs.py", line 169, in solve
obj,valid = solve_prog(new_p,quiet)
File "build/bdist.macosx-10.8-intel/egg/cvxpy/procedures/solve_prog.py", line 44, in solve_prog
sol = call_solver(p_expanded,quiet)
File "build/bdist.macosx-10.8-intel/egg/cvxpy/procedures/call_solver.py", line 78, in call_solver
r = solvers.conelp(c,G,h,dims,A,b)
File "/Library/Python/2.7/site-packages/cvxopt/coneprog.py", line 687, in conelp
raise ValueError("Rank(A) < p or Rank([G; A]) < n")
ValueError: Rank(A) < p or Rank([G; A]) < n
当我查看"/Library/Python/2.7/site-packages/cvxopt/coneprog.py"的第687行时,实际上是在处理算术错误。
685 try: f = kktsolver(W)
686 except ArithmeticError:..
687 raise ValueError("Rank(A) < p or Rank([G; A]) < n")
这有道理吗?为什么算术错误,例如OverflowError
, ZeroDivisionError
, FloatingPointError
,除非cvxpy扩展了ArithmeticError,否则意味着问题描述不当,即Rank(A) < p或Rank([G;A]) < n"?