Function XGDMatrixNumNonMissing

src/c_api/c_api.cc:920–924

We name the function non-missing instead of non-zero since zero is perfectly valid for XGBoost.

// We name the function non-missing instead of non-zero since zero is perfectly valid for XGBoost.
XGB_DLL int XGDMatrixNumNonMissing(DMatrixHandle handle, bst_ulong *out) {
  return GetDMatrixIntegralInfo(handle, out, [](DMatrix const *p_fmat) {
    return static_cast<bst_ulong>(p_fmat->Info().num_nonzero_);
  });
}

XGB_DLL int XGDMatrixDataSplitMode(DMatrixHandle handle, bst_ulong *out) {
  return GetDMatrixIntegralInfo(handle, out, [](DMatrix const *p_fmat) {