Method Finalize

cpp/src/arrow/compute/kernels/aggregate_tdigest.cc:102–123

  }

  Status Finalize(KernelContext* ctx, Datum* out) override {
    const int64_t out_length = options.q.size();
    auto out_data = ArrayData::Make(float64(), out_length, 0);
    out_data->buffers.resize(2, nullptr);
    ARROW_ASSIGN_OR_RAISE(out_data->buffers[1],
                          ctx->Allocate(out_length * sizeof(double)));
    double* out_buffer = out_data->template GetMutableValues<double>(1);

    if (this->tdigest.is_empty() || !this->all_valid || this->count < options.min_count) {
      ARROW_ASSIGN_OR_RAISE(out_data->buffers[0], ctx->AllocateBitmap(out_length));
      std::memset(out_data->buffers[0]->mutable_data(), 0x00,
                  out_data->buffers[0]->size());
      std::fill(out_buffer, out_buffer + out_length, 0.0);
      out_data->null_count = out_length;
    } else {
      for (int64_t i = 0; i < out_length; ++i) {
        out_buffer[i] = this->tdigest.Quantile(this->options.q[i]);
      }
    }
    *out = Datum(std::move(out_data));
    return Status::OK();
  }

  const TDigestOptions options;
  TDigest tdigest;