MATLAB: For loop inside structure

for loopMATLABstructures

I have a structure called (level3) and inside it some fields (e.g x0, vx). each field is an array with some values as shown in the screenshot.

I would like to go through these fields values and multply them as follows:

x(1,1)*vx(1,1)

x(2,1)*vx(2,1)

x(3,1)*vx(3,1)

…. and so on.

so I got at the end 10 arrays of results of x

I tried to do it like this but I just got one array with the last value.

fields = fieldnames(level3);
for k=1:10
    x = [x0. * vx];
end

Thanks in advance

Best Answer

I got the answer after many tries as follows:

for n = 1:10

x{n} = level3(n).x0. * (level3(n).vx)

end

Related Solutions

MATLAB: Ode 45 in a loop

You have a couple of problems with your code. Your ode_research does not follow the ordinary form (dydy = ode_f(t,y)) that ode45 expects. Then your use of a string for the first argument is a bit arcane. I would expect something like this would be better:

t = linspace(1,10);
vf(1) = 30 ; %some random constant value
vfx = vf(1); % needed in the function ode_research_x
x(1) = -3;% starting point for x
vp = v_initial; % or whatever you have as initial condition
for i = 1:length(t)-1
    vfx = vf(1); % this vfx is then used by the ode_research_x function
    [tx,vx] = ode45(@(t,vx) ode_research_x(t,vx,vfx), t(i:i+1), vp(1)); % I am not sure but the time step seems like an issue
    x(i+1) =  x(i) + vx(end).*tx;
    vp(1) = vx;
    vf(1) = 30; % some new constant value calculated in the loop (I've shown a random value)
end
%function to define the ode
function dudt = ode_research_x(t,vx,vfx)
% Some initialization of the constants, I assume.
dudt = 18*mu_f*Cd*Rep*(vx - vfx)/(rho_p*d^2*24); % all the variables except vx and vfx are constant values in the same workspace so I haven't shown their values but they are defined 
end

This looks like some attemt to integrate an equation of motion, if that is the case this is not a good way to go about it. In that case you should integrate the second-order ODE (i.e. the two coupled first order-ODEs) and handle the evolution of the force inside the ode_research_x - function.

HTH

MATLAB: Problem of for loop

If you mean to sum all the values use

for k=1:10
  x(k)=sin(k)
end
out=sum(x)

%or without a for loop

k=1:10
x=sin(k)
out=sum(x)

Best Answer

Related Solutions

MATLAB: Ode 45 in a loop

MATLAB: Problem of for loop

Related Question