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1answer
12 views

should weights be scaled too?

I am using supervised learning algorithms (specificly SVM) on my data. I know that scaling was needed for my input data. however as I am also adding weights (using pairwise comparison), I am not sure ...
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1answer
23 views

Scaling in SVM (why and how to , plus references)

Hi I know why feature scaling is preferred in SVM, I have two questions: 1-does anyone know of legit articles of books explaining it. I am writing my thesis and I need references. It doesnt have to be ...
1
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1answer
63 views

optimal scaling / CATREG for imputed data

I have a data set with 5 different kinds of nutrient statuses and I want to see whether they are associated with categorical / ordinal grades at school. I have multiple covariates which I will ...
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0answers
38 views

What is PRINCIPAL HESSAIN Direction Model, how and where can I use it?

I'm a M.Tech student going through my academic project-work, here I have asked to develop a optimal design and a best equation to fit the data for a Leaching, Solvent extraction and Electrowinning ...
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0answers
32 views

Question on scaling data

I have been reading Elements of Statistical Learning. And I saw some example R codes written online. I realise that very often the explanatory variables $X$ (the data of the predictors) are ...
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0answers
14 views

what does Task in multitask learning mean?

I'm new in multitask learning. I didn't exactly understand what is Tasks in multitask learning ? every task are single training data or what ?
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46 views

Scaling data in machine learning algorithm

I am currently working on a linear classifier, which uses the statistical learning paradigm; that is, no knowledge about the distribution from which that training data are drawn from is available. ...
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1answer
225 views

Can I categorize the factor scores to use them as predictors of an ordinal logistic regression?

I was wondering if I can categorize the factor saved scores by taking their quartiles (or some other measures, I am not sure what should I use!) as cut points and use them as predictors in an ordinal ...
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0answers
211 views

Optimal scaling level for variables categorized from continuous data

A variable was categorized into 10 equally spaced intervals from a continuous variable which was originally in proportion. Now, we have to use this variable in CATREG procedure. If we choose the ...
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0answers
171 views

Can I use optimally scaled variables for a factor analysis to account for rotation? If I can then how?

I have discussed this issue several times in this site, but I am asking it again for a final justification from the experts of our community. I wanted to extract four factors (I should call dimensions ...
2
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0answers
300 views

How to obtain optimally scaled data from homals in R?

I am using the homals-package in R to optimally quantify my data that contains categorical (nominal and ordinal) as well as numerical variables. My goal is to ...
5
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1answer
706 views

What is the advantage of transforming variables from nominal to ordinal/numerical when it reduces variance explained in CatPCA?

Context I have a dataset of 8 categorical variables. And I want to apply Categorical Principal Component Analysis (CatPCA). Before doing that, I have been advised to look at the transformation plots ...
5
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1answer
1k views

How to calculate Rousseeuw’s and Croux’ (1993) Qn scale estimator for large samples?

Let Qn = Cqn.{|Xi-Xj|;i < j}_(k) so for a very short sample like {1,3,6,2,7,5} it can be calculated from finding the kth static order of pairwise differences: 7 6 5 3 2 1 1 6 5 4 2 1 2 5 4 3 1 ...
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1answer
116 views

Parametric Surface Reconstruction from Contours with Quick Rescaling

I'm looking to construct a 3-D surface of a part of the brain based on 2-D contours from cross-sectional slices from multiple angles. Once I get this shape, I want to "fit" it to another set of ...
5
votes
1answer
541 views

How can I use optimal scaling to scale an ordinal categorical variable?

In an answer to this question about treating categorical data as continuous, optimal scaling was mentioned. How does this method work and how is it applied?