172 search results for "PCA"

Looking to the PCA scores with GGobi

October 21, 2012
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Looking to the PCA scores with GGobi

In this post I continue with the unsupervised exploration of oil spectra, which we have seen in previous post ( PCA with "ChemoSpec" - 001).In the manual "ChemoSpec:An R Package for Chemometric Analysis of Spectroscopic Data", (page 23) there is a brie...

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PCA with "ChemoSpec" – 001

October 20, 2012
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PCA with "ChemoSpec" – 001

In my last post about "ChemoSpec package" (Hierarchical Cluster Analysis (ChemoSpec) - 02), we saw the two cluster groups (one for olive oil, other for sunflower oil), and also another sub-clusters for the sunflower oil.Continue reading the manual "Che...

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Color Palettes in HCL Space

October 12, 2012
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Color Palettes in HCL Space

This is a quick follow-up to my previous post about Color Palettes in RGB Space. Achim Zeileis had commented that, perhaps, it would be more informative to evaluate the color palettes in HCL (polar LUV) space, as that spectrum more accurately describes how humans perceive color. Perhaps more clear trends would emerge in HCL space,

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Long-term precipitation data for your location from the US Historical Climatology Network using R

September 19, 2012
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Long-term precipitation data for your location from the US Historical Climatology Network using R

Abstract Long-term daily precipitation records from the US Historical Climatology Network (USHCN) are processed and summarized using R. Below is R code which examines the data from Livermore, CA, the closest available USHCN station to my present home ...

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DESeq vs edgeR Comparison

September 18, 2012
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DESeq vs edgeR Comparison

Update (Dec 18, 2012): Please see this related post I wrote about differential isoform expression analysis with Cuffdiff 2.DESeq and edgeR are two methods and R packages for analyzing quantitative readouts (in the form of counts) from high-throughput e...

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What’s the smallest amount you can’t make with 5 coins ?

September 16, 2012
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What’s the smallest amount you can’t make with 5 coins ?

My amazing, awesome wife often comes up with the little puzzles for our amazing children, and this one seemed destined to be solved in R. So, using up to 5 coins (1p, 2p, 5p, 10p, 20p and 50p) first she asked our kids whether they could make every val...

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PCA or Polluting your Clever Analysis

August 31, 2012
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PCA or Polluting your Clever Analysis


When I learned about principal component analysis (PCA), I thought it would be really useful in big data analysis, but that's not true if you want to do prediction. I tried PCA in my first competition at kaggle, but it delivered bad results. This post illustrates how PCA can pollute good predictors.
When I started examining this problem,...

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Why R for Mass Spectrometrist and Computational Proteomics

August 25, 2012
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Why R for Mass Spectrometrist and Computational Proteomics

Why R:Actually, It is a common practice the integration of the statistical analysis of the resulted data and in silico predictions of the data generated in your manuscript and your daily research. Mass spectrometrist, biologist and bioinformaticians c...

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2014 Winter Olympics: Home Court Advantage – Russia

August 22, 2012
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2014 Winter Olympics: Home Court Advantage – Russia

winter olympics home country advantage

"Russia is a riddle wrapped in a mystery inside an enigma."
 -- Winston Churchill, radio address in 1939

A couple of weeks ago, Graph of the Week published an article describing the significant improvement in medals won by the host...

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ARMA Models for Trading

August 21, 2012
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ARMA Models for Trading

In this tutorial I am going to share my R&D and trading experience using the well-known from statistics Autoregressive Moving Average Model (ARMA). There is a lot written about these models, however, I strongly recommend Introductory Time Series with R, which I find is a perfect combination between light theoretical background and practical implementations in

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