How to use nested FOR loop to create a matrix of answers?

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Jan 2022-11-15

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1851648-how-to-use-nested-for-loop-to-create-a-matrix-of-answers

评论： Jan 2022-11-24

Hello, I'm relatively new to MATLAB and I'm struggling on producing a matrix with a size of 30x6 using nested FOR loops.

I want 30 different values for the variable 'theta' between 0-90 and 6 different values for the variable 'Vs' between 0-60, put it through the equations and return the answers as a 30 by 6 matrix. I've tried having theta = (3:3:90)' and Vs = 10:10:60 but that's as far as my knowledge goes. I'm not entirely sure where to put the for loops in this code either.

Thanks in advance, I appreciate any kind of help.

% INPUT DATA

% Specified constants:

k = 0.02;

g = 9.81;

dt = 0.01;

% Input the initial condition:

theta = 55; % Launch angle in degrees.

rads = theta*(pi/180); % Converts degrees to radians.

Vs = 10; % Launch speed m/s.

u(1) = Vs*cos(rads);

v(1) = Vs*sin(rads);

% Launch pad location:

x(1) = 0;

y(1) = 0;

% Compute approximate solution of the trajecotry of flight.

% Repeat up to 2000 time, i.e., until ball hits the ground.

for n = 1:1:2000

u(n+1) = u(n)- dt * (k * sqrt(u(n)^2+v(n)^2) * u(n));

v(n+1) = v(n)- dt * (k * sqrt(u(n)^2+v(n)^2) * v(n) + g);

x(n+1) = x(n) + u(n) * dt;

y(n+1) = y(n) + v(n) * dt;

% Determination of when the object hits ground:

if y(n+1) < 0

slope = (y(n+1) - y(n))/(x(n+1) - x(n));

b = y(n) - slope * x(n);

xhit = - b/slope;

plot(x,y)

fprintf(' The length of the shot = %5.2f \n', xhit)

end

% Once object hits terminate the computations with a break:

if y(n+1) < 0

break;

end

The length of the shot = 8.27

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Answer 1

Jan 2022-11-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1851648-how-to-use-nested-for-loop-to-create-a-matrix-of-answers#answer_1100608

编辑：Jan 2022-11-15

在 MATLAB Online 中打开

thetaL = 3:3:90;
VsL = 10:10:60;
... Other constants
Result = NaN(numel(thetaL), numel(VsL));
for itheta = 1:numel(thetaL)
    theta = thetaL(itheta);
    rads = theta*(pi/180); % Converts degrees to radians.
    for iVs = 1:numel(VsL)
        Vs = VsL(iVs);
        ... Your code:
        u(1) = Vs*cos(rads);
        v(1) = Vs*sin(rads);
        ...
            
        Result(itheta, iVs) = xhit;
    end
end