Index out of bounds?

I was given a project to work on with a crank with link R, and a slider with link L. I am supposed to run the algorithm to calculate from 1 to 100 each being a different point to calculate the angle between the links R and L, position of the slider, angular velocity between R and L, velocity of the slider, and then angular acceleration between R and L, and acceleration of the slider.

Part of the code which I have written is as follows:

    R = 0.5; % m length of the lower arm of the slider
    L = 1.25; % m length of the upper arm of the slider
    thetadot = 2*pi; % radians/second angular velocity of the slider
    theta = linspace(0,4*pi,100); % all angles of the lower slider arm

    for i = 1:100

    f1 = @(phi) (R*sin(theta(i))) + (L*sin(phi)) - H;
    df1 = @(phi) (L*(cos(phi)));
    phi0 = (pi/4);
    phi(i) = newtraph(f1,df1,phi0,0.0001,50);
    % invoke newtraph to find roots for phi

    f2 = @(s) (R*cos(theta(i))) + (L*cos(phi(i))) - s;
    df2 = @(s) -1;
    s0 = sqrt((H.^2) + ((R + L)^2));
    s(i) = newtraph(f2,df2,s0,0.0001,50);
    % invoke newtraph to find roots for s

    A1 = [-L*sin(phi(i)), -1; L*cos(phi(i)), 0]; 
    * b1 = [(R*sin(theta(i))*thetadot(i)); (-R*cos(theta(i))*thetadot(i))];
    x1 = A1\b1; % x1 = angualar and linear velocity
    phidot = x1(1); sdot = x1(2);

This is only part of the code, however, even with just this piece of the code I am getting an error that states:

    Attempted to access thetadot(2); index out of bounds because     numel(thetadot)=1.

• the line with the * is the line where the error appears. I do not understand what this error means or how to fix it, any help is greatly appreciated.

Thank you!

Lia

Answer 1

[Matt J]

Since thetadot=2*pi is just a scalar, you cannot run a loop over thetadot(i) for i=1...100 as if thetadot were a length 100 vector. Perhaps you meant to have theta(i) there instead of thetadot(i).

[Lia]

THANK YOU!!!!