清空筛选条件
清空筛选条件

matrix normalization in matlab

119 次查看（过去 30 天）
jenifer
jenifer 2013-1-30
编辑： DGM 2022-12-11
hi.. i want normalize a matrix (129 x 128)..please help me with matlab codes

请先登录，再回答此问题。

采纳的回答

Thorsten
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));
  3 个评论
显示 1更早的评论
Irawati Roy
Irawati Roy 2022-12-11
You missed a dot before the division operation for a 2d matrix
DGM
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

请先登录，再进行评论。

更多回答（3 个）

Matt J
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
显示 1更早的评论
jenifer
jenifer 2013-1-30
ya... but how can i get a single value from whole matrix...
Jan
Jan 2013-1-30
Please, jenifer, we have asked you to define "normalization" exactly. It wastes time if we guess what you mean.

请先登录，再进行评论。

Jing
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.
DGM
DGM 2022-12-11
Ran in:
Since R2018a, you can use normalize() to perform normalization in various different ways.
A = 1:6
A = 1×6
1 2 3 4 5 6
B1 = normalize(A,'range') % default range is [0 1]
B1 = 1×6
0 0.2000 0.4000 0.6000 0.8000 1.0000
B2 = normalize(A,'range',[-1 2]) % but you can specify any range
B2 = 1×6
-1.0000 -0.4000 0.2000 0.8000 1.4000 2.0000
B3 = normalize(A,'zscore','std') % zero-center and scale to have std=1
B3 = 1×6
-1.3363 -0.8018 -0.2673 0.2673 0.8018 1.3363
B4 = normalize(A,'norm',2) % normalize by vector p-norm (default p=2)
B4 = 1×6
0.1048 0.2097 0.3145 0.4193 0.5241 0.6290

类别

在 Help Center 和 File Exchange 中查找有关 Matrix Indexing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by