I am trying to create a loop where a variable changes and the answer is saved in the matrix below

A1=9200000;A2=420000000;A3=350000;n1=0;n2=5.3;n3=7.65;Ea1=108400;Ea2=350000;Ea3=525000;R=82.057;

k1mat = zeros(1,29);k2mat = zeros(1,29);k3mat = zeros(1,29);c1mat = zeros(1,29);c2mat = zeros(1,29);c3mat = zeros(1,29);

Tmat = 500:25:1200

for i = [500:25:1200]

T=(i+25)

c1=(3.6000*10^-04)*(1/R*T);

%c4=0

c3 = (2.4000*10^-04)*(1/R*T);

c4 = 0.0664*(1/R*T);

k1=(A1*T^(n1)*exp(-Ea1/(R*T)));

k2=(A2*T^(n2)*exp(-Ea2/(R*T)));

k3=(A3*T^(n3)*exp(-Ea3/(R*T)));

k1mat(T) = k1;

k2mat(T) = k2;

k3mat(T) = k3;

c1mat(T) = c1;

c3mat(T) = c3;

c4mat(T) = c4;

end

I have looked through multiple answers but cannot find answers on something like this specifically. It is producing matrices of zeros.... Thank you!

Answer 1

[Ameer Hamza]

Check this code and compare it with your code to find the issue

A1=9200000;A2=420000000;A3=350000;n1=0;n2=5.3;n3=7.65;Ea1=108400;Ea2=350000;Ea3=525000;R=82.057;
k1mat = zeros(1,29);k2mat = zeros(1,29);k3mat = zeros(1,29);c1mat = zeros(1,29);c2mat = zeros(1,29);c3mat = zeros(1,29);c4mat = zeros(1,29);
Tmat = 500:25:1200;
for i = 1:numel(Tmat)
    T = Tmat(i)+25;
    c1=(3.6000*10^-04)*(1/R*T); 
    %c4=0
    c3 = (2.4000*10^-04)*(1/R*T);
    c4 = 0.0664*(1/R*T);
    k1=(A1*T^(n1)*exp(-Ea1/(R*T)));
    k2=(A2*T^(n2)*exp(-Ea2/(R*T)));
    k3=(A3*T^(n3)*exp(-Ea3/(R*T)));
    k1mat(i) = k1;
    k2mat(i) = k2;
    k3mat(i) = k3;
    c1mat(i) = c1;
    c3mat(i) = c3;
    c4mat(i) = c4;
end

[Nikolaj Kloch]

You are incredible. This is for a combustion class and you have saved me! What was the numel command in the "for i = 1:numel(Tmat)"

[Ameer Hamza]

I am glad to be of help!!!

numel() is number of elements in vector. For a 1D vector, it is same as length().