I am calling outside functions for this code, but when I am getting an error saying I have too many output arguments. I think the error is within my function LandingDistance

%% problem 2
% user-defined function to compute the horizontal distance 
% traveled by a projectile knowing the launch angle, the initial velocity, 
% and geometric parameters defining the initial coordinates of the projectile.
d1 = 0.0876;
d2 = 0.1190;
v0 = 3.2;
thetaL = 50;
g = 9.81; % gravitational acceleration in m/s^2

% call initial coords function and initial velocity function
[x0, y0] = InitialCoords(d1, d2, thetaL); % input units: m, m, degrees, output units: m
[v0x, v0y] = InitialVelocityComponents(v0, thetaL); % input units: m/s de,grees, output units: m/s

%Solve the y equation for tLand by calling your Quadratic function.
a = -0.5*g; % g = acceleration due to gravity in m/s^2
b = v0y; % initial velocity in y direction
c = y0; % initial y position
plusOrMinus = -1;
root = Quadratic(a, b, c, plusOrMinus); % neg root
tLand = root; 

% plug tLand into the x eqn to get xLand
xLand = LandingDistance(d1, d2, v0, thetaL);
fprintf('For launch angle = %.1f degrees and v0 = %.1f m/s, the landing distance is %.2f m \n', thetaL, v0, xLand)

Error using LandingDistance

Too many output arguments.

Error in HW3_projectile (line 36)

xLand = LandingDistance(d1, d2, v0, thetaL);

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

_____________________________________

function code

% landing distance function
function LandingDistance(d1, d2, v0, thetaL)
% x_Land --> the horizontal distance traveled by the projectile
g = 9.81; % gravitational acceleration in m/s^2
[x0, y0] = InitialCoords(d1, d2, thetaL) % input units: m, m, degrees, output units: m
[v0x, v0y] = InitialVelocityComponents(v0, thetaL) % input units: m/s de,grees, output units: m/s
a = -0.5*g; % g = acceleration due to gravity in m/s^2
b = v0y; % initial velocity in y direction
c = y0; % initial y position
plusOrMinus = -1;
[root] = Quadratic(a, b, c, plusOrMinus); % neg root
tLand = root
xLand = x0 + (v0x*tLand)
end

Not enough input arguments.

Error in LandingDistance (line 6)

[x0, y0] = InitialCoords(d1, d2, thetaL)

^^

>>

Answer 1

[Star Strider]

The reason is that ‘LandingDistance’ doesn’t return any outputs:

function LandingDistance(d1, d2, v0, thetaL)

You probably want it to be:

function xLand = LandingDistance(d1, d2, v0, thetaL)

If so, that should work.

.

EDIT — Corrected typographical errors.

[ERIN]

you're right, I realized that shortly after i posted the question. But now I am getting a different error. I also realized I had some equations in there wrong. I'm not sure if it's my quadratic function now, cause it's about the variable a, I've tried assigning it inside the landingDistance function and outside but it's not working.

% quadratic function
function [root] = Quadratic(a, b, c, plusOrMinus)
root = (-b + plusOrMinus * (sqrt(b^2 - (4*a*c)))) / (2 * a);

if (b^2 - (4*a*c)) >= 0
    % Compute the root if the discriminant is non-negative
    root = (-b + plusOrMinus * (sqrt(b^2 - (4*a*c)))) / (2 * a);
else
    % Display error message for complex roots
    error('The coefficients yield a complex root. Abort Program')
end

% landing distance function
    function [xLand] = LandingDistance(d1, d2, v0, thetaL)
        % xLand --> the horizontal distance traveled by the projectile
        v0x = v0 * cosd(thetaL);
        v0y = v0 * sind(thetaL);
        x0 = d2*cosd(thetaL);
        y0 = d1 + d2*sind(thetaL);
        [root] = Quadratic(a, b, c, plusOrMinus); % neg root
        tLand = root;
        xLand = x0 + (v0x*tLand);
    end

__________

d1 = 0.0876;
d2 = 0.1190;
v0 = 3.2;
thetaL = 50;
a = -0.5*g; % g = acceleration due to gravity in m/s^2
b = v0y; % initial velocity in y direction
c = y0; % initial y position
plusOrMinus = -1;
[xLand] = LandingDistance(d1, d2, v0, thetaL);
fprintf('For launch angle = %.1f degrees and v0 = %.1f m/s, the landing distance is %.2f m \n', thetaL, v0, xLand)

Unrecognized function or variable 'a'.

Error in LandingDistance (line 9)

[root] = Quadratic(a, b, c, plusOrMinus); % neg root

^

Error in test1 (line 12)

[xLand] = LandingDistance(d1, d2, v0, thetaL);

[ERIN]

I figured it out, I needed to put the a, b, c, variables before calling the root function

[Star Strider]

In your code, you defined ‘a’, ‘b’, and ‘c’ however you passed ‘d1’, ‘d2’, and ‘v0’ (and ‘thetaL’) to ‘LandingDistance’. I’m honestly a bit lost as to what you should be passiinng to it.

[ERIN]

I was missing an equation that needed a, b, and c. basically I was leaving out an equation and had variables assigned after calling functions instead of before

[Star Strider]

O.K.