calculation of a mean matrix
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Hi I have two matrices
a = [1 2 3; 2 3 4]
and
b = [2 3 4; 3 4 5];
I want a mean output matrix "c," whose output should be
c= [1.5 2.5 3.5; 2.5 3.5 4.5].
so basically "c" should have a mean of respective parameters and same dimension as "a" and "b". Can someone help?
Thanks, Subrat
댓글 수: 1
Yanbo
2012년 8월 15일
you might just simply add a to b, and them divide the sum by 2. Or, are you looking for a specific command?
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Oleg Komarov
2012년 8월 15일
Unfortunately your example doesn't allow to propose a unique solution, i.e.:
c1 = [mean(a); mean(b)]
c2 = squeeze(mean(cat(3,a,b),3));
c1 simply takes the vertical mean (along rows) of a and then concatenates the vertical mean of b
c2 takes the mean of row 1 from a AND b and then concatenates the mean of the second row fro the two matrices.
Which one do you want?
추가 답변 (3개)
Image Analyst
2012년 8월 15일
a = [1 2 3; 2 3 4];
b = [2 3 4; 3 4 5];
c = (a+b)/2
In the command window:
c =
1.5 2.5 3.5
2.5 3.5 4.5
댓글 수: 3
Alfredo Scigliani
2023년 4월 25일
what if you have a ridculous amount of matrices (1000) and you want to find the average? I think a for loop, but not sure how.
Steven Lord
2023년 4월 25일
what if you have a ridculous amount of matrices (1000)
Then I'd recommend you revise the code to avoid that scenario. More likely than not you dynamically created variables with numbered names like x1, x2, x3, etc.
Can you do that? Yes.
Should you do this? The general consensus is no. That Answers post explains why this is generally discouraged and offers several alternative approaches.
Benjamin Klugah-Brown
2020년 8월 9일
what if matrix a and b have different size
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Walter Roberson
2020년 8월 10일
If by NA you mean NaN, then you would have to use
mean(cat(3, A1, B1), 3, 'omitnan')
or you would have to use something like
maskA = isnan(A1);
maskB = isnan(B1);
C1 = (A1 + B1) / 2;
C1(maskA) = B1(maskA);
C1(maskB) = A1(maskB);
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