my_acceleration.m

function [ax,ay,az]=my_acceleration(x,y,z,t)
    % Help documentation of "my_acceleration"
    % This function computes the acceleration in the x- and y-directions given
    % three vectors of position in x- and y-directions as a function of time
    % x = x-position
    % y = y-position
    % z = z-position
    % t = time
    % output
    % ax = acceleration in x-direction
    % ay = acceleration in y-direction
    % az = acceleration in z-direction

    function v=diff_match_dims(x,t)
      v=zeros(length(t),1);
      v(1:end-1)=diff(x)./diff(t);
      v(end)=v(end-1);
    end

    [vx,vy,vz]=my_velocity(x,y,z,t);

    ax = diff_match_dims(vx',t);
    ay = diff_match_dims(vy',t);
    az = diff_match_dims(vz',t);
    %added apostrophe for derivatives of velocity

end