docs: public static int nullity(SingularValueDecomposition_F64 svd , double threshold ) {
          int ret = 0;
  
          double w[]= svd.getSingularValues();
  
          int N = svd.numberOfSingularValues();
  
          int numCol = svd.numCols();
  
          for( int j = 0; j < N; j++ ) {
              if( w[j] <= threshold) ret++;
          }
          return ret + numCol-N;
      }