matrix normalization in matlab
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Thorsten
2013-1-30
To normalize a matrix such that all values fall in the range [0, 1] use
Anorm = (A - min2(A))/(max2(A) - min2(A));
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DGM
2022-12-11
编辑:DGM
2022-12-11
There ./ is not needed here, since the denominator is a scalar.
That said, there is no function called min2() or max2(), nor can I find evidence that there were functions by those names which have since been removed. Maybe they used to be part of one of the toolboxes.
Alternatively, you could do:
Anorm = (A - min(A(:)))/(max(A(:)) - min(A(:)));
or you could do
Anorm = (A - min(A,[],'all'))/(max(A,[],'all') - min(A,[],'all'));
though the latter option wouldn't have worked circa 2013
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Matt J
2013-1-30
You need to decide how you want to define the amplitude of the matrix first. Maybe you want this
normalized = A/norm(A);
or maybe this
normalized = A/max(abs(A(:)))
3 个评论
Jan
2013-1-30
Please, jenifer, we have asked you to define "normalization" exactly. It wastes time if we guess what you mean.
Jing
2013-1-30
You can use 'normc' or 'normr' for normalization. 'c' or 'r' stands for columns or rows that you want to normalize.
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DGM
2022-12-11
A = 1:6
B1 = normalize(A,'range') % default range is [0 1]
B2 = normalize(A,'range',[-1 2]) % but you can specify any range
B3 = normalize(A,'zscore','std') % zero-center and scale to have std=1
B4 = normalize(A,'norm',2) % normalize by vector p-norm (default p=2)
2 个评论
Sinan Islam
2024-8-3,0:27
The normalize function in matlab either works on columns or rows. We want a function that normalizes the matrix as a whole. We are not looking for normalizing features or observations. So the calculation must be made on global minimum and global maximum of the matrix. Thats why we flatten the matrix into one vector before doing any calculation.
DGM
2024-8-3,4:18
As others have mentioned, "normalize" is a terribly vague word. If the goal is to rescale the entire array with respect to global statistics, then yes, reshaping the array is one way to do so.
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