How to fill specific elements of vector based on indexes of another vector?

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Safia
Safia 2022-10-28
编辑： Safia 2022-10-29
Hi all!
i have a problem and i want to share with you in order to get some help.
i have two vectors d1 , d2 with same dimension as shown :
d1=[10 0 0 0 0
0 11 0 0 0
0 0 0 20 0
0 0 0 0 21]
d2=[10 0 0 0 0
0 15 0 0 0
0 0 0 20 0
0 0 0 0 12]
i did a comparison between each elements in both d1 and d1 as follow :
if d1<d2, keep value in d1 and put "0" in d2
if d1>d2, keep value in d2 and put "0" in d1
if d1=d2 , i add 100 to both value and keep them in same matrices.(i did this in order to distinguish the needed value later because it may exist other same values in my real matrix).
the result as shown :
d1=[110 0 0 0 0
0 11 0 0 0
0 0 0 120 0
0 0 0 0 0]
d2=[110 0 0 0 0
0 0 0 0 0
0 0 0 120 0
0 0 0 0 12]
i put the result with an order in two vectors V1 and V2 as following( here they have same dimension but usually with different dimension :
V1=[110 V2=[110
11 120
120] 12]
after this i will focus only for value >100 . so i extracted their indexes
I1=[1 I2=[1
3] 2]
I have taken into account another condition, G1 and G2 containing values corresponding to V1 and V2 successively.
G1=[3 G2=[3
5 6
3] 4]
Now , i will compare just the extracted elements :
for i=1:size(I1,1)
if G1(I1(i))>G2(I2(i))
V1(I1(i)=0
V2(I2(i))=V2(I2(i))-100 %return the intial value
elseif G1(I1(i))=<G2(I2(i))
V1(I1(i)=V1(I1(i)-100
V2(I2(i))=0
end
end
the result is the following :
V1=[10 V2=[0
11 0
20] 12]
after this i will remove zero rows.
the final result:
V1=[10 V2=[12]
11
20]
I did all this but i can't acheive the required result.
i hope that you could help me.
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Safia
Safia 2022-10-28
编辑：Safia 2022-10-29
@Torsten I have provided a full explanation above hoping that you can understand my problem.

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回答（1 个）

Image Analyst
Image Analyst 2022-10-29
Please format your code and paragraphs better. It's difficult to read. This is as far as I got:
d1=[10 0 0 0 0 0 11 0 0 0 0 0 0 20 0 0 0 0 0 21];
d2=[10 0 0 0 0 0 15 0 0 0 0 0 0 20 0 0 0 0 0 12];
% Not sure what this means: V1=[110 V2=[110 11 120 120] 12]
% Not sure what this means I1=[1 I2=[1 3] 2]
% "if d1<d2, keep value in d1 and put "0" in d2 if d1>d2,"
mask = d1 > d2;
d2(mask) = 0; % d1 remains untouched -- keeps it's original values.
% "keep value in d2 and put "0" in d1 if d1=d2"
mask = d1 == d2;
d1(mask) = 0 % d2 remains untouched.
% "add 100 to both value and keep them in same matrices." but apparently
% only where there are non-zero values.
mask = d1 == 0;
d1(mask) = d1(mask) + 100;
mask = d2 == 0;
d2(mask) = d2(mask) + 100;
Sorry I can't help you with the rest. The rest of your explanation is an unintelligible run-on sentence where we have no idea what you're saying. Please use spaces, bullet points, separate lines, and code-formatting with the code icon/button to make it readable and understandable.
  1 个评论
Safia
Safia 2022-10-29
@Image Analyst i will explain more :
as i said d1 and d2 are two intial matrices. I want to compare theirs elements having same position. i already do that by a condition "if" mentioned above.
after getting result of new d1 and d2 , i remove zero rows,and i did a sum of elements V1=sum(d1,2) and V2=sum(d2,2).
the objective is to keep value when (d1=d2 ) in V1 or V2, ( as i said if d1 = d2 i keep value in both).
so i used another condition, i have two vectors G1 and G2 display correspending values of V1 and V2.
so i have already distinguish the needed value that i want to compare(as i said i add 100).
i extracted their indexes and i put the condition :
if G1 correspending to needed element in V1 > G2 correspending to needed element in V2 , so i will remove the element from V1 and keep it in V2.
in the opposite case, i reverse.
also when G1=G2, i keep value in V1 and remove it from V2.
the example above shows all this steps.
the final result shows , when i have same value in same position in d1 and d2, it should be kept in one of them, therfore i did all mentioned steps.
i hope that you understand, i'm here for any clarification. thank you so much

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