How do I create a create 'for' loop to compute time, position, velocity and add to running sum?

for t=[0:0.1:8]
    p(t)=(A*t^4)-(B*t^3)+(C*t^2)-(D*t)+E;
    v(t)=(4*A*t^3)-(3*B*t^2)+(2*C*t)-D;
end

This is what I have so far. I need to determine position and velocity over the range 0<=t<=8 in time steps of .1 seconds. When I try running this I get an error that it can't access p(0). How do I make this code work as intended?

Answer 1

[José-Luis]

Indexes in Matlab start with one, not zero. which_ever_array(0) will return an error. In your example, you could, amongst other things, add a counter variable:

counter = 1;
for t=[0:0.1:8]
    p(counter)=(A*t^4)-(B*t^3)+(C*t^2)-(D*t)+E;
    v(counter)=(4*A*t^3)-(3*B*t^2)+(2*C*t)-D;
    counter = counter + 1;
end

Note that even then it would be a good idea to preallocate

counter = 1;
p = NaN * ones(numel(0:0.1:8),1);
v = p;
for t=[0:0.1:8]
    p(counter)=(A*t^4)-(B*t^3)+(C*t^2)-(D*t)+E;
    v(counter)=(4*A*t^3)-(3*B*t^2)+(2*C*t)-D;
    counter = counter + 1;
end