normalization , colums, rows
2 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
Dhurgham Al-karawi
el 26 de Mayo de 2018
Editada: Dhurgham Al-karawi
el 26 de Mayo de 2018
Hi everyone,
May I know which way correct to do normalization for a matrix by colums or rows?
Thanks.
2 comentarios
Ameer Hamza
el 26 de Mayo de 2018
The correct way depends on what you are trying to do, how are you normalizing etc. You need to specify what is your purpose for normalizing the matrix.
Respuesta aceptada
Jan
el 26 de Mayo de 2018
Editada: Jan
el 26 de Mayo de 2018
x = rand(242, 256),
xNRow = x ./ sum(x, 2); % Auto-expanding, Matlab >= R2016b
xNCol = x ./ sum(x, 1);
For older Matlab versions:
xNRow = bsxfun(@rdivide, x, sum(x, 2));
xNCol = bsxfun(@rdivide, x, sum(x, 1));
Now the rows or columns are normalized, such the the sum is 1.0. But perhaps you want the norm to be 1.0?
xNRow = x ./ vecnorm(x, 2); % Auto-expanding, vecnorm needs >= R2017b
xNCol = x ./ vecnorm(x, 1);
Or with older Matlab versions:
xNRow = x ./ sqrt(sum(x .* x), 2)); % Auto-expanding, >= R2016b
xNCol = x ./ sqrt(sum(x .* x), 1));
or again with bsxfun.
There are more methods for a "normalization": Set the mean to zero, and/or the std to 1 or such that the maximum peak height is 1.0. So you have to find out, what you need mathematically. Then the implementation in Matlab is easy.
2 comentarios
Más respuestas (0)
Ver también
Categorías
Más información sobre Matrix Indexing en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!