MATLAB: Plotting help, please

matlab code plot plotting

Ok, so I'be this program here I've got to do for a class, all of the things it asks for are done except one, the plotting part, it's a program that calculates the angle of the position of bars 3 and 4 of a 4 bar mechanism, the thing is, I have to plot the answer to both of those angles for all 360 degrees, and when I do that, all it does is tell me it will ignore all complex numbers, and 4 horizontal lines were plotted (each angle has two possible answers), then I decided since it would ignore the complex numbers I'd just plot the absolute value for the angles, and after doing that it only plotted two angles, yet still they were completely horizontal, does anybody think they could look at that part of my code and help me find out what's wrong?
Here's the pastebin of my code (excuse the spanish, but I guess you can still understand the variables and such, also, variables suck as k1, k2..etc are already defined before this bit): http://pastebin.com/ziyxcAHy

Best Answer

  • Change the following lines in your code to use ./ instead of /
    tan3a = (-E + sqrt(E.^2 - (4 .* D .* F)))./ (2 .* D);% note ./
    tan3b = (-E - sqrt(E.^2 - (4 .* D .* F)))./ (2 .* D);
    tan4a = (-B + sqrt(B.^2 - (4 .* A .* C)))./ (2 .* A);
    tan4b = (-B - sqrt(B.^2 - (4 .* A .* C)))./ (2 .* A);