Need help setting up my for loop

I am having trouble setting my Fx = but is not working

fs = 100; %sampling rate Hz
m = 90; %male subject kg
t = [1/fs:1/fs:length(Fx)/fs];
mfoot = (0.0145)*(m); % kg
g =9.8;
COMx = RANK(:,1) + (RTOE(:,1)-RANK(:,1)/2); %m
COMy = RTOE(:,2) + (RANK(:,2)-RTOE(:,2)/2); %m

dxd = COP(:,1) - COMx;
dyd = COMy;

dxp = COMx - RANK(:,1);
dyp = RANK(:,2) - COMy;

%alpha = 

for i = length(Fx)
    
    Rx(:,i) = sum(mfoot*g(:,i));
end

Answer 1

[Walter Roberson]

g is a scalar. You are trying to use g(:,i) . That is only going to work when i is 1, which would then be g(:,1) which would be the same as g(1,1) which would be the same as the scalar g. But when i reaches 2, g(:,2) is going to fail as there is only one column in g.

Your posted code does not define Fx to have its length() taken.

Oh, and notice that you did not use for i = 1: something, you went for for i = something which is going to do a single iteration with i having the single value defined.