Why am I getting errors with this code?

Could someone help me figure out why I am getting all kinds of errors with my code please. I have attached the *.m file containing my code. Thank you very much.

[Andrew Newell]

Are your functions in separate files?

[Andrew Newell]

The script at the top doesn't call any of the functions.

[J]

No, they are all in the same file.

Answer 1

[Greig]

There are a few issues here. First of all, you cannot declare functions in a standard m-file script. They have to be in separate m-files, or trajectory.m needs to be a function.

I recommend renaming it to "Get_trajectory.m" and making the start and end

function Stats = Get_trajectory

.... % all the other functions 

end % this is needed since all other function use end

Second, by defining trajectory as a function, we need to declare what the output should be. I guess it is all the output from your various functions? If so, then we need to call your various functions get their output and return this as the output of the Get_trajectory function (the "Stats" variable above). So, add something like this after you ask for the user input...

[xt,yt] = trajectory(v0,theta,t,g);
ymax = peakheight(v0,theta,g);
tmax = timeflight(v0,theta,g);
xmax = range(v0,theta,g);

Stats = [xt, yt, ymax, tmax, xmax];

Third, in the peakheight function, you a missing a * in the ymax calculation

    function [ymax] = peakheight(v0,theta,varargin)
        if nargin == 2
            g=9.8;  % if g not specified g=9.8
            ymax = ((v0^2)*((sin(theta))^2))/2*g;
        elseif nargin == 3
            %if the user enter the value for g
            g=varargin{1};
            ymax = ((v0^2)*((sin(theta))^2))/2*g;
        end
    end

Lastly, to call the function simply type

Stats = Get_trajectory;

Type in the prompted inputs, and the stats variable will contain all of the output you need. I have attached my updated version for you to see.

Edit: The file is now attached!

[J]

Greig, I really appreciate your help. Thank you very much.