Timeline for Interpreting PCA figures in layman terms
Current License: CC BY-SA 3.0
14 events
| when toggle format | what | by | license | comment | |
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| Nov 3, 2017 at 22:26 | vote | accept | Amir Rahbaran | ||
| Oct 31, 2017 at 14:47 | answer | added | Sextus Empiricus | timeline score: 7 | |
| Oct 31, 2017 at 0:16 | comment | added | amoeba |
The left and bottom axis are correlations - this is wrong. As written in the linked thread, bottom/left axes show normalized (to unit sum of squares) PC1 and PC2 scores. Regarding your questions, (1) Yes, (2) Yes, (3) These values correspond to PCA eigenvectors (that you see in the prcomp output) scaled by the PCA eigenvalues and scaled further by the $\sqrt{n}$. All of that is extensively covered on our website and some relevant threads are linked in the thread you read, e.g. see stats.stackexchange.com/questions/141085.
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| Oct 30, 2017 at 21:50 | comment | added | Amir Rahbaran | @ttnphns: added data and the little code scippet | |
| Oct 30, 2017 at 21:49 | history | edited | Amir Rahbaran | CC BY-SA 3.0 |
added data and code snippet
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| Oct 30, 2017 at 16:42 | comment | added | ttnphns | A PCA biplot is an overlay scatterplot of component loadings and component data point scores in the space of the (usually first two) components. Axes could be gauged by different scales depending on whether the "loadings" are loadings or eigenvectors and whether the scores are raw or standardized (unit variance). Without data and syntax it may be difficult to figure out at once what are the scales of your axes. I might recommend you - if you want a concrete guidance - to post data (at least) plus the syntax. | |
| Oct 30, 2017 at 16:12 | history | edited | Amir Rahbaran | CC BY-SA 3.0 |
minor language editing
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| Oct 30, 2017 at 12:38 | history | reopened |
mdewey kjetil b halvorsen♦ gung - Reinstate Monica |
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| Oct 30, 2017 at 12:38 | comment | added | gung - Reinstate Monica | The OP has stated what they understood from the duplicate & what they still don't understand. I'm voting to reopen. | |
| Oct 30, 2017 at 9:13 | review | Reopen votes | |||
| Oct 30, 2017 at 12:38 | |||||
| Oct 30, 2017 at 8:57 | history | edited | Amir Rahbaran | CC BY-SA 3.0 |
made questions more concrete after reading suggested post
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| Oct 29, 2017 at 12:03 | history | closed |
amoeba Peter Flom |
Duplicate of Interpretation of biplots in principal components analysis | |
| Oct 28, 2017 at 22:54 | review | Close votes | |||
| Oct 29, 2017 at 12:03 | |||||
| Oct 28, 2017 at 21:14 | history | asked | Amir Rahbaran | CC BY-SA 3.0 |