Matlab Tips

Matlab Programming Style Guidelines

1. Some important tricks and commands:

   1. print(gcf, ‘-depsc’, ‘fig1MB4.eps’); %–for saving the Figure as an eps image%—-for printing title with a user defined variable, in this case ‘fn’

   2. title(['Composite Diff (Fechner Law) of : ',int2str(fn)],’Color’,'r’)%—-for displaying with one or more user defined variables, in this case ‘hrzntl’ and ‘vrtcl’

   3. disp(['Size of MB is: ',int2str(hrzntl),'x',int2str(vrtcl)])%—–replacing some elements in a matrix with other value

   4. a(a >0.9 & a<1.1) = 3 ;

• • • • 1. SELECTING ONLY A SPECIFIC NUMBER OF ROWS FULFILLING A CONDITION

           1. 1. Assume you have the following data matrix:

              2. A =

              3. 1 11 22 33

              4. 44 13 12 33

              5. 1 14 33 44

              6. Now I would like to delete all rows of this matrix which don't accomplish e.g. the following condition.

              7. octave:6> A(:, 4) == 33

              8. ans =

              9. 1

              10. 1

              11. 0

              12. And I'll get the matrix of this form which only selects these rows:

              13. A_new =

              14. 1 11 22 33

              15. 44 13 12 33

              16. Try:

              17. A = [

              18. 1 11 22 33

              19. 44 13 12 33

              20. 1 14 33 44

              21. ];

              22. idx = ( A(:,4)==33 );

              23. A_new = A(idx,:)

• • 1. Draw curve on each other

       1. 1. 1. DRAWING FIGURE ON EACH OTHER

                1. 1. figure

                      1. a= [70.5, 63.05, 74, 75.9;99.31, 97.79, 99.34, 99.42;89.17, 87.02, 88.68, 89.75];';

                      2. b=[2.43, 2.45, 0.07, 0.07];

                      3. [AX,H1,H2] =plotyy([1:4],a, [1:4],b, 'bar', 'bar');

                      4. set(H1) % a

                      5. set(H2,'FaceColor','b') % b

                      6. get(H2,'Type') %For illustration purpose only.

                      7. pH = arrayfun(@(x) allchild(x),H2);

                      8. set(pH,'FaceAlpha',0.25);

                      9. ylabel(AX(1),'something')

                      10. ylabel(AX(2),'other thing')