Comments on: Deriving biological meaning from principal components analysis

By: ioni

ioni — Wed, 16 Jul 2008 06:39:50 +0000

Hi,

Thank you. Found it very helpful including the R code.

By: Rewards, output and academia « What You’re Doing Is Rather Desperate

Rewards, output and academia « What You’re Doing Is Rather Desperate — Mon, 10 Mar 2008 06:50:59 +0000

[...] Deriving biological meaning from principal components analysis - by Mike [...]

By: gamini.gunasekera

gamini.gunasekera — Sun, 18 Nov 2007 05:47:04 +0000

sir,
i have some idea of PCA. Why do you need to reduce the dimensions in the data.
would not stepwise multivatiate analysis be more usefl for interpretation of variation?

look forward to a helpful answer.

with to learn PCA. any good books and suggestions.

you essay was very useful to a beginner. afterall we must relate the components to the original data.

thank you

gamini/ error in firt msg re name

By: lydia

lydia — Sun, 16 Sep 2007 06:25:55 +0000

thanks a lot for the interpretation.

By: Animesh Sharma

Animesh Sharma — Fri, 10 Aug 2007 13:32:55 +0000

Thanks Mike for this update, apart from PCA, I really learned a lot about plotting in R from this post .
Regarding PCA, I use to understand this just as a dimensionality reduction technique where components were ranked on the basis of their contribution towards the data’s variance.
One suggestion in your code [ http://www.bioinformaticszen.com/wp-content/uploads/2007/07/pca_post.txt ], we need to do a ‘find and replace’ for the ‘/Users/mike/Desktop/post/’ string to User’s working directory before running the code in R [ source('pca_post.txt') ].

By: Bio::Blogs #13 « What You’re Doing Is Rather Desperate

Bio::Blogs #13 « What You’re Doing Is Rather Desperate — Fri, 03 Aug 2007 01:35:47 +0000

[...] up is Mike again with a detailed look at principal components analysis. This is a very useful multivariate statistical method which I’ve used a lot myself and he [...]