# How to create a loop for varying the values of A, B & C according to months?

2 views (last 30 days)
WASIM ASHRAF on 25 Jul 2021
Commented: WASIM ASHRAF on 26 Jul 2021
% FOR the month of January from ASHRAE-1972 MODEL
% A,B,C are constant and depends on month value.
A = 1164;
B = 0.149;
C = 0.109;
theta_z = 30;
I_bn = A*exp(-B/cosd(theta_z));
I_b = I_bn*cosd(theta_z);
I_d = C*I_bn;
% for Feb month the values of A, B & C are-
A = 1095;
B = 0.135;
C = 0.119;
% How to create a loop which can calculate I_bn, I_b & I_d as per each month?

VBBV on 25 Jul 2021
A, B and C are not constants, they are actually variables.
1. Define, vectors for each of the parameters, A, B and C
2. Then use a for loop to each of the parameters, A, B and C
3. Store the values into I_bn, I_b & I_d vectors for each of the months as below
months = 1:12; % assuming 12 in year !!
A = rand(1,12)*1500; % values for each month
B = rand(1,12);
C = rand(1,12);
theta_z = 30;
for i = 1: length(months)
I_bn(i) = A(i)*exp(-B(i)/cosd(theta_z));
I_b(i) = I_bn*cosd(theta_z);
I_d(i) = C(i)*I_bn;
end
##### 2 CommentsShowHide 1 older comment
WASIM ASHRAF on 26 Jul 2021
Thanks, I understood it very nicely.