How to; For loop of angle in projectile motion

Im trying to get a for loop to run a projectile motion from an angle pi/6 to pi/3 and then run a function that finds the range for each and returns the maximum one (would be at 45 degrees), so far I believe I have the for loop run through the angles correctly but when the range function runs it does not display the corresponding range values, it only returns the value for pi/6, for the increment number of times:

g = 9.82; %gravity
v0 = 100; %inital velocity
theta0 = pi/6;
T = (2*v0*sin(theta0))/g; % Theoretical flight time
t = linspace(0,T,1001);
[r,v] = Projectile(t,v0,theta0); %link to projectile function
figure(1), plot(r(:,1),r(:,2));
xlabel('Distance (m)');
ylabel('Height (m)');
legend('Trajectory path');

R = FindRange(r); %link to find range function
disp("Range = " + (R) + "m");
m = max(r(:,2));%Max height
disp("Maximum Height = " + (m) + "m");
disp("Flight time = " + (T) + "sec");
for theta0 = pi/6:pi/180:pi/3
    R1 = FindRange(r);
    disp (R1)
end

Answer 1

[KSSV]

You are not updating the theta0 to find the range. You need to input theta0 to the function.

clc; clear all ;
g = 9.82; %gravity
v0 = 100; %inital velocity
theta0 = pi/6;
T = (2*v0*sin(theta0))/g; % Theoretical flight time
t = linspace(0,T,1001);
[r,v] = Projectile(t,v0,theta0); %link to projectile function
figure(1), plot(r(:,1),r(:,2));
xlabel('Distance (m)');
ylabel('Height (m)');
legend('Trajectory path');
R = FindRange(r); %link to find range function
disp("Range = " + (R) + "m");
m = max(r(:,2));%Max height
disp("Maximum Height = " + (m) + "m");
disp("Flight time = " + (T) + "sec");
for theta0 = pi/6:pi/180:pi/3
    T = (2*v0*sin(theta0))/g; % Theoretical flight time
    t = linspace(0,T,1001);
    [r,v] = Projectile(t,v0,theta0); %link to projectile function
    R1 = FindRange(r);
    disp (R1)
end

[Aston]

Ah okay I see, the problem I have now is in the FindRange function, if isempty is true, which returns the 'Solution end before the projectile hits the ground' error and im not sure why

function R = FindRange_template(r)

x = r(:,1);

y = r(:,2);

indx = find(y<0);

if isempty(indx);

error('Solution ends before projectile hits the ground');

end;

k = indx(1);

x1 = x(k-1);y1 = y(k-1);

x2 = x(k); y2 = y(k);

R = (x1+x2)/2;

end

Answer 2

[Sam Chak]

Hi @Aston

g      = 9.82;                      % gravity
v0     = 100;                       % inital velocity
theta0 = pi/6;
T      = (2*v0*sin(theta0))/g;      % Theoretical flight time
t      = linspace(0,T,1001);
[r, v] = Projectile(t,v0,theta0);   % link to projectile function

Unrecognized function or variable 'Projectile'.

figure(1), 
plot(r(:,1), r(:,2));
xlabel('Distance (m)');
ylabel('Height (m)');
legend('Trajectory path');

R      = FindRange(r); %link to find range function
disp("Range = " + (R) + "m");

m      = max(r(:,2));%Max height
disp("Maximum Height = " + (m) + "m");
disp("Flight time = " + (T) + "sec");

Suggest the for loop in this structure:

% Range of initial angle
theta0 = pi/6:pi/180:pi/3

for j  = 1:length(theta0)
    
    % Call function that uses theta0(j)
    
end

[Aston]

what would that function for theta0(j) look like?