Linked Questions

134
votes
5answers
91k views

What's the difference between principal component analysis and multidimensional scaling?

How are PCA and classical MDS different? How about MDS versus nonmetric MDS? Is there a time when you would prefer one over the other? How do the interpretations differ?
4
votes
1answer
8k views

(Multiple) Correspondence Analysis for count data entered as binary variables

I have a data set, 1014 cases and 55 variables which are binary and is in the form of ...
6
votes
1answer
493 views

Similarities and dissimilarities in classical multidimensional scaling

I am having trouble reconciling between several terms in MDS. According to [1], Section 14.8, Classical MDS takes similarities as inputs. In [2], also cited in Wikipedia, Classical MDS takes ...
3
votes
1answer
411 views

Using metric MDS with non-metric distances and assessing the fit quality

I'm going to perform MDS by means of cmdscale function of standard R library. I spent several hours googling it and finally have ...
1
vote
0answers
908 views

nMDS in vegan for soil data

I am working with abiotic soil data such as bulk density, moisture levels and soil chemistry as response data (some quantitative some as percentages) and a mix of abiotic and biotic data as ...
2
votes
1answer
281 views

Is first dimension more informative in multidimensional scaling?

A property of Principal Components Analysis (PCA) is that the first dimension is the most informative, next the second and so on. Is this property true also for multidimensional scaling (MDS)?
1
vote
0answers
351 views

When the distance metric is not Euclidean, the metric Multidimensional Scaling (MDS) is nonlinear?

As it is commonly known, classic metric MDS (under Euclidean distance metric) is a linear dimension reduction method (equivalent to PCA), and it is also known to us that non-metric MDS is nonlinear, ...
4
votes
1answer
126 views

Multidimensional Scaling terminology question

The picture below concerns Multidimensional Scaling (MDS), in which there are two terms " Matrix of distance "(δ) and "euclidean distance"(d). I don't understand the difference between them. Can you ...
1
vote
0answers
165 views

Which MDS to use for interactions frequency distance matrix

I have kind of 'distance matrix', every element of which is represented by number of interactions (contacts) between pair of positions on single path-like(curve) object. It is stated, that number of ...
1
vote
1answer
131 views

Dimensionality reduction with least distance distortion

Question: Could I find a dimensionality reduction algorithm without or with minimal distance (cosine) distortion? Background: I would like to visualize in 2D a sample of news texts for which I also ...
1
vote
0answers
52 views

What's right/wrong with using multi-dimensional scaling to analyze voting patterns of for members of an 11-member city council?

I'm trying to analyze voting patterns of an 11-member city council over a period of five years. Description of data file: each row (vector) is labeled as a councilmember; each column records ...
0
votes
1answer
42 views

How could a variable length binary string be encoded as an SVM feature?

I have data which is a binary string, e.g. 10001001 or 111100000001. The length can vary between 3 and 13 characters in length. It represents a pattern found in nature where the length is variable ...