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Nov 3, 2023 at 7:15 history edited David Marx CC BY-SA 4.0
their -> they're
Nov 21, 2013 at 23:26 history edited Scortchi CC BY-SA 3.0
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Aug 5, 2013 at 4:40 history edited David Marx CC BY-SA 3.0
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Aug 5, 2013 at 4:38 comment added David Marx Updated my answer to demonstrate why your plot looks the way it does. Short version: because X and Y are tightly correlated, PCA combines them into a single dimension to allow you to explore the relationship between those variables and Z. The X-Z and Y-Z relationships are effectively the same thing because X and Y are so tightly correlated. Your PCA transformation is showing you the much less structured (XY)-Z relationship.
Aug 5, 2013 at 4:33 history edited David Marx CC BY-SA 3.0
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Aug 5, 2013 at 4:27 history edited David Marx CC BY-SA 3.0
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Aug 5, 2013 at 3:55 history edited David Marx CC BY-SA 3.0
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Aug 4, 2013 at 19:44 comment added Nancy Thanks for the quick response. I've read though the link you suggested several times-- agreed, it's a fantastic resource. I suspect that I'm over thinking my question. My concern is that x and y are very tightly correlated with plotted against each other, but the "flattened" plot looks like a bunch of random points. Is this just a result of having the z data being so uncorrelated?
Aug 4, 2013 at 19:22 history answered David Marx CC BY-SA 3.0