docs: public float[][] getPhi() {
          float[][] phi = new float[K][V];
          if (SAMPLE_LAG > 0) {
              for (int k = 0; k < K; k++) {
                  for (int w = 0; w < V; w++) {
                      phi[k][w] = phisum[k][w] / numstats;
                  }
              }
          } else {
              for (int k = 0; k < K; k++) {
                  for (int w = 0; w < V; w++) {
                      phi[k][w] = (word_topic_matrix[w][k] + beta) / (nwsum[k] + V * beta);
                  }
              }
          }
          return phi;
      }