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How can I normalize data between 0 and 1 ? I want to use logsig...

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Platon
Platon el 13 de Mayo de 2013
Comentada: shazia el 10 de Ag. de 2023
All is in the question: I want to use logsig as a transfer function for the hidden neurones so I have to normalize data between 0 and 1. The mapminmax function in NN tool box normalize data between -1 and 1 so it does not correspond to what I'm looking for.

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José-Luis
José-Luis el 15 de Mayo de 2013
bla = 100.*randn(1,10)
norm_data = (bla - min(bla)) / ( max(bla) - min(bla) )
  3 comentarios
José-Luis
José-Luis el 15 de Mayo de 2013
Yes, provided you use the same normalization bounds (the min and max of both datasets). To rescale, please look at the below code.
bla = 100.*randn(1,10)
minVal = min(bla);
maxVal = max(bla);
norm_data = (bla - minVal) / ( maxVal - minVal )
your_original_data = minVal + norm_data.*(maxVal - minVal)
Aviral Petwal
Aviral Petwal el 22 de Jun. de 2018
No need to denormalize the data. For your Test set also you can normalize the data with the same parameters and feed it to NN. If you trained on Normalised data just normalize your test set using same parameters and feed the data to NN.

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Más respuestas (4)

Jurgen
Jurgen el 15 de Mayo de 2013
NDATA = mat2gray(DATA);
  2 comentarios
JohnDylon
JohnDylon el 8 de Oct. de 2016
Is this exactly a min-max normalizaton?
Greg Heath
Greg Heath el 8 de Oct. de 2016
Editada: Greg Heath el 8 de Oct. de 2016
Why not just try it and find out?
close all, clear all, clc
[ x1 , t1 ] = simplefit_dataset;
DATA1 = [ x1, t1 ];
DATA2 = [ x1; t1 ];
whos DATA1 DATA2
minmax1 = minmax(DATA1)
minmax2 = minmax(DATA2)
minmaxMTG1 = minmax( mat2gray(DATA1) )
minmaxMTG2 = minmax( mat2gray(DATA2) )
Hope this helps.
Greg

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Abhijit Bhattacharjee
Abhijit Bhattacharjee el 25 de Mayo de 2022
As of MATLAB R2018a, there is an easy one-liner command that can do this for you. It's called NORMALIZE.
Here is an example, where a denotes the vector of data:
a_normalized = normalize(a, 'range');
  1 comentario
shazia
shazia el 10 de Ag. de 2023
How about denormalization what comand should we use to denormalize after training to calculate the error. please guide

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Greg Heath
Greg Heath el 11 de Mayo de 2017
Editada: Greg Heath el 11 de Mayo de 2017
I like to calculate min, mean, std and max to detect outliers with standardized data (zero mean/unit variance). For normalization and denormalization I just let the training function use defaults
tansig and linear
however, if the ouput is naturally bounded use
tansig and tansig
or
tansig and logsig
In short, unless you are plotting you don't have to worry about anything except outliers.
Hope this helps.
Greg

Angus Steele
Angus Steele el 20 de Sept. de 2017
function [ newValue ] = math_scale_values( originalValue, minOriginalRange, maxOriginalRange, minNewRange, maxNewRange )
% MATH_SCALE_VALUES
% Converts a value from one range into another
% (maxNewRange - minNewRange)(originalValue - minOriginalRange)
% y = ----------------------------------------------------------- + minNewRange
% (maxOriginalRange - minOriginalRange)
newValue = minNewRange + (((maxNewRange - minNewRange) * (originalValue - minOriginalRange))/(maxOriginalRange - minOriginalRange));
end

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