# example of the data file with 2-level errors in x and y # # x y dx1 dx2 dy1 dy2 dx1(2nd) dx2(2nd) dy1(2nd) dy2(2nd) # 1.5 100. 0.5 0.5 20. 20. 0.8 0.8 3. 7. 5.5 120. 0.5 0.5 30. 30. 0.8 0.8 4. 7. 6.5 70. 0.5 0.5 20. 20. 0.8 0.8 10. 12. 9.5 98. 0.5 0.5 10. 10. 0.8 0.8 8. 5. 10.5 102. 0.5 0.5 13 13. 0.8 0.8 10. 10. 12.5 130. 0.5 0.5 25. 25. 0.8 0.8 10. 20. 16.5 90. 0.5 0.5 10. 10. 0.8 0.8 10. 20.