mds

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mds [2012/10/25 14:49] melancon [Coming back to the algorithm] |
mds [2012/11/20 12:43] (current) bpinaud [Multi-dimensional scaling (MDS)] |
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==== Multi-dimensional scaling (MDS) ==== | ==== Multi-dimensional scaling (MDS) ==== | ||

- | Now, I am assuming you came to this page after reading the [[pca|PCA section]], so you've heard of the Cars dataset. The PCA visualization is fine, except maybe that it projects the data along line axis -- those axis tat are given by the two largest eigenvalues of the covariance matrix. These axis are linear combination of the original axis, those associated with the original attributes in the data. But what if attributes do not correlate linearly? Should the projection necessarily obey a linear transform? THis is what we investigate here. Find a way to project data based on the relative distance between objects rather than from linear dependencies between variables (attributes). | + | Now, I am assuming you came to this page after reading the [[pca|PCA section]], so you've heard of the Cars dataset. The PCA visualization is fine, except maybe that it projects the data along line axis -- those axis that are given by the two largest eigenvalues of the covariance matrix. These axis are linear combination of the original axis, those associated with the original attributes in the data. But what if attributes do not correlate linearly? Should the projection necessarily obey a linear transform? THis is what we investigate here. Find a way to project data based on the relative distance between objects rather than from linear dependencies between variables (attributes). |

{{:mds_cars.png?direct&300 |}}MDS is a long studied problem originating from social sciences. [[usereditable:bibliography_and_external_links|The book by Borg and Groenen]] provides a good historical background on MDS. | {{:mds_cars.png?direct&300 |}}MDS is a long studied problem originating from social sciences. [[usereditable:bibliography_and_external_links|The book by Borg and Groenen]] provides a good historical background on MDS. |

/net/html/perso/melancon/Visual_Analytics_Course/data/pages/mds.txt · Last modified: 2012/11/20 12:43 by bpinaud