-->v=(1:5) v = ! 1. 2. 3. 4. 5. ! -->v' ans = ! 1. ! ! 2. ! ! 3. ! ! 4. ! ! 5. ! -->A=v'*v A = ! 1. 2. 3. 4. 5. ! ! 2. 4. 6. 8. 10. ! ! 3. 6. 9. 12. 15. ! ! 4. 8. 12. 16. 20. ! ! 5. 10. 15. 20. 25. !
-->A(1,:) ans = ! 1. 2. 3. 4. 5. ! -->A(:,$) ans = ! 5. ! ! 10. ! ! 15. ! ! 20. ! ! 25. ! -->A(1,:)*A(:,$) ans = 275. -->diag(A) ans = ! 1. ! ! 4. ! ! 9. ! ! 16. ! ! 25. ! -->triu(A) // Partie triangulaire superieure ans = ! 1. 2. 3. 4. 5. ! ! 0. 4. 6. 8. 10. ! ! 0. 0. 9. 12. 15. ! ! 0. 0. 0. 16. 20. ! ! 0. 0. 0. 0. 25. ! -->tril(A) // Partie triangulaire inferieure ans = ! 1. 0. 0. 0. 0. ! ! 2. 4. 0. 0. 0. ! ! 3. 6. 9. 0. 0. ! ! 4. 8. 12. 16. 0. ! ! 5. 10. 15. 20. 25. !
-->tA=A' tA = ! 1. 2. 3. 4. 5. ! ! 2. 4. 6. 8. 10. ! ! 3. 6. 9. 12. 15. ! ! 4. 8. 12. 16. 20. ! ! 5. 10. 15. 20. 25. !
-->B=rand (5,5) B = column 1 to 4 ! 0.2922267 0.5015342 0.9184708 0.2806498 ! ! 0.5664249 0.4368588 0.0437334 0.1280058 ! ! 0.4826472 0.2693125 0.4818509 0.7783129 ! ! 0.3321719 0.6325745 0.2639556 0.2119030 ! ! 0.5935095 0.4051954 0.4148104 0.1121355 ! column 5 ! 0.6856896 ! ! 0.1531217 ! ! 0.6970851 ! ! 0.8415518 ! ! 0.4062025 ! -->B*A ans = column 1 to 4 ! 8.6017545 17.203509 25.805264 34.407018 ! ! 2.8489744 5.6979489 8.5469233 11.395898 ! ! 9.0655016 18.131003 27.196505 36.262006 ! ! 7.4445591 14.889118 22.333677 29.778236 ! ! 5.1278856 10.255771 15.383657 20.511543 ! column 5 ! 43.008773 ! ! 14.244872 ! ! 45.327508 ! ! 37.222795 ! ! 25.639428 ! -->B-A ans = column 1 to 4 ! - 0.7077733 - 1.4984658 - 2.0815292 - 3.7193502 ! ! - 1.4335751 - 3.5631412 - 5.9562666 - 7.8719942 ! ! - 2.5173528 - 5.7306875 - 8.5181491 - 11.221687 ! ! - 3.6678281 - 7.3674255 - 11.736044 - 15.788097 ! ! - 4.4064905 - 9.5948046 - 14.58519 - 19.887865 ! column 5 ! - 4.3143104 ! ! - 9.8468783 ! ! - 14.302915 ! ! - 19.158448 ! ! - 24.593798 ! -->A/B ans = column 1 to 4 ! 1.8084953 - 0.8201656 4.4019359 2.6544968 ! ! 3.6169905 - 1.6403313 8.8038718 5.3089936 ! ! 5.4254858 - 2.4604969 13.205808 7.9634903 ! ! 7.233981 - 3.2806625 17.607744 10.617987 ! ! 9.0424763 - 4.1008281 22.00968 13.272484 ! column 5 ! - 3.488166 ! ! - 6.976332 ! ! - 10.464498 ! ! - 13.952664 ! ! - 17.44083 !
-->A(3,4) ans = 12.
-->n=5 // pour fixer une valeur a n n = 5. -->C=2*eye(n,n) -diag(ones(n-1,1),1)-diag(ones(n-1,1),-1) C = ! 2. - 1. 0. 0. 0. ! ! - 1. 2. - 1. 0. 0. ! ! 0. - 1. 2. - 1. 0. ! ! 0. 0. - 1. 2. - 1. ! ! 0. 0. 0. - 1. 2. !