int numberColumns = 2;
int numberRows = 4;
int[][] defaultArray = { {2, 7},
  {8, 4},
  {5, 1},
  {6, 9} };

void setup() {
}

int[][] transpose(int[][] defaultArray) {
  int[][] temp = new int[numberColumns][numberRows];
  for (int i = 0; i < numberRows; i++) {
    for (int j = 0; j < numberColumns; j++) {
      temp[j][i] = defaultArray[i][j];
    }
  }
  return temp;
}