calculate result

[Silevoem]

I have compiled using cuda12.3 and highs1.6.0 on wsl2 and installed pycupdlp. After running the example, I found that the calculated value is inconsistent with the result of scipy.optimize.linprog. Is this because of wsl?

[WenzhouXia]

I also met this problem. It's confusing

[WenzhouXia]

I find that if use cvxpy and modified "maximize" to "minimize", the optimal objetive of both is same. But the solution is still wrong, which I think came from the wrong function of returning solutions.

[WenzhouXia]

using this modified code can fix this problem:

py::dict get_solution() {
py::dict sol;
if (!ifSovled) {
cupdlp_printf("Please solve the problem first!\n");
return sol;
}
else{
// ----- x 部分 -----
{
// 1) 在堆上开辟一块新的缓冲区
cupdlp_float buf = (cupdlp_float)std::malloc(nCols * sizeof(cupdlp_float));
if (!buf) throw std::bad_alloc();

      // 2) 拷贝解
      std::memcpy(buf, col_value, nCols * sizeof(cupdlp_float));

      // 3) 创建一个 capsule，Python 端释放时会调用 free(buf)
      py::capsule free_when_done(buf, [](void *f){
          std::free(f);
      });

      // 4) 把 buf 和 capsule 一起给 numpy array
      sol["x"] = py::array_t<cupdlp_float>(
          { static_cast<ssize_t>(nCols) },                // shape
          { sizeof(cupdlp_float) },                       // strides
          buf,                                             // data ptr
          free_when_done                                  // capsule
      );
  }

  // ----- y 部分（同理） -----
  {
      cupdlp_float *buf = (cupdlp_float*)std::malloc(nRows * sizeof(cupdlp_float));
      if (!buf) throw std::bad_alloc();
      std::memcpy(buf, row_dual, nRows * sizeof(cupdlp_float));
      py::capsule free_when_done(buf, [](void *f){
          std::free(f);
      });
      sol["y"] = py::array_t<cupdlp_float>(
          { static_cast<ssize_t>(nRows) },
          { sizeof(cupdlp_float) },
          buf,
          free_when_done
      );
  }

  // ----- 额外返回的标量字段 -----
  sol["iters"]         = iters;
  sol["solve_time"]    = solve_time;
  sol["scaling_time"]  = scaling_time;
  sol["presolve_time"] = presolve_time;
  sol["PrimalObj"]     = PrimalObj;
  sol["DualObj"]       = DualObj;
  sol["DualityGap"]    = DualityGap;
  sol["Comp"]          = Comp;
  sol["PrimalFeas"]    = PrimalFeas;
  sol["DualFeas"]      = DualFeas;
  sol["PrimalObjAvg"]  = PrimalObjAvg;
  sol["DualObjAvg"]    = DualObjAvg;
  sol["DualityGapAvg"] = DualityGapAvg;
  sol["CompAvg"]       = CompAvg;
  sol["PrimalFeasAvg"] = PrimalFeasAvg;
  sol["DualFeasAvg"]   = DualFeasAvg;

  return sol;
}

}