# Simple problem using for loop/array

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JaydudeZ on 14 Oct 2016
Edited: Ganesh Hegade on 25 Oct 2016
Hello, I am quite new to Matlab and have read through Help sections, forums etc, but I still cannot get my basic code to correctly execute multiplying a constant by array (I have tried matrix too) and give me the answer that is correct.
clear all; clc
A=0.4; % bond albedo
AU=1.496*10^11
row=5.67*10^-8; % boltz const
L=3.84*10^26; % lum sun
num1=(1-A)*L;
% calc denominator
den=16*pi*row;
temp_range=[373.15; 273.15] %matrix 2x1
% temp_range=[373.15 273.15] %array
k=den.*((temp_range).^4)
% calc habitable zone
distance=(num1/k).^0.5
hab=distance/AU
% second attempt
%
% for i=temp_range;
% k=den.*(i.^4)
% end
% d=(num1/k).^0.5
% hab=d/AU
% disp(hab)
% code
end
The output of this gives me answers to one of the temperature range only, either 0.4 or 0.8, with the other value in the array Or matrix (tested both) being zero. eg.Output gives ;
% hab =
0.4316 0
and the same result but with a 2x1 matrix, that second value should be 0.8xxx etc. The second attempt yields exactly the same result.
What steps have I done wrong/missed completely? (I have not provided the entire code, just a snippet for the problem seen, if required I will provide the constants missing/entire code)
Kind regards,
Jay
##### 2 CommentsShowHide 1 older comment
JaydudeZ on 14 Oct 2016
Edited, see code again- row was Stefan Boltzman constant

Ganesh Hegade on 25 Oct 2016
Edited: Ganesh Hegade on 25 Oct 2016
Hi,
Please use this. It gives the output as you have requested above.
clc;
A=0.4; % bond albedo
AU=1.496*10^11;
row=5.67*10^-8; % boltz const
L=3.84*10^26; % lum sun
num1=(1-A)*L;
% calc denominator
den=16*pi*row;
temp_range=[373.15; 273.15]; %matrix 2x1
% temp_range=[373.15 273.15] %array
k=den.*((temp_range).^4);
% calc habitable zone
for i = 1:length(k)
distance(i)=(num1/k(i)).^0.5;
end;
hab=distance/AU;
Thanks.

Pritesh Shah on 14 Oct 2016
May be, you can you debug your program. Give completer code to give solution

JaydudeZ on 15 Oct 2016
bump