# Matrix calculation(replacing a new value instead of matrix element)

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shirin mhd on 31 Mar 2022
Commented: Voss on 31 Mar 2022
Hi everyone
I've written this code. my purpose is to make a matrix(1*3), which each element (T1,T2,T3) of that is calculated in upper lines. But it doesn't work. what should i do?
a1=7;
a2=12;
a3=4;
w1=min([a1,a2,a3]);
f1=double(a1-w1);
f2=double(a2-w1);
f3=double(a3-w1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f1==0
final=w1;
T1=-10e10;
else
T1=f1;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f2==0
final=w1;
T2=-10e10;
else
T2=f2;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f3==0
final=w1;
T3=-10e10;
else
T3=f3;
end
T=[T1,T2,T3]
i expect after run T becomes [3 8 -10e10]
but what code does is:
T =
1.0e+11 *
0.0000 0.0000 -1.0000
in other word, I want replace some elements in a matrix with new calculated value during some steps.which part is wrong?
I appreciate any help.

the cyclist on 31 Mar 2022
The code is doing what you expect, but the format of the output obscures the result. Try using format long, and you'll see the result more clearly:
a1=7;
a2=12;
a3=4;
w1=min([a1,a2,a3]);
f1=double(a1-w1);
f2=double(a2-w1);
f3=double(a3-w1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f1==0
final=w1;
T1=-10e10;
else
T1=f1;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f2==0
final=w1;
T2=-10e10;
else
T2=f2;
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if f3==0
final=w1;
T3=-10e10;
else
T3=f3;
end
format long
T=[T1,T2,T3]
T = 1×3
1.0e+11 * 0.000000000030000 0.000000000080000 -1.000000000000000
T1
T1 =
3
T2
T2 =
8
T3
T3 =
-1.000000000000000e+11
shirin mhd on 31 Mar 2022
Thank you for your help and attention. I really appreciate your kindness.

Voss on 31 Mar 2022
The result T you get is correct. The confusion is because of how T is displayed in the Command Window. You can look at one element at a time to see them, or you can change how numbers are displayed in the Command Window:
Looking at individual elements of T:
T = [3 8 -10e10] % shows all of T, as-is
T = 1×3
1.0e+11 * 0.0000 0.0000 -1.0000
T(1)
ans = 3
T(2)
ans = 8
T(3)
ans = -1.0000e+11
Changing the Command WIndow format:
format long
T
T = 1×3
1.0e+11 * 0.000000000030000 0.000000000080000 -1.000000000000000
##### 2 CommentsShowHide 1 older comment
Voss on 31 Mar 2022
You're welcome!

Image Analyst on 31 Mar 2022
Those are the values. It's just that when using 1e11 as the base, the 3 and 8 don't show in the display. To solve that put this at the top of your code
format long g
##### 2 CommentsShowHide 1 older comment
shirin mhd on 31 Mar 2022
Thank you for your help and attention. I really appreciate your kindness.