262 search results for "pca"

Prune GWAS data in R

March 29, 2011
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Prune GWAS data in R

Hansong Wang, our biostats professor here at the Hawaii Cancer Center, generously gave me some R code that goes through a SNP annotation file (i.e. a mapfile) and selects SNPs that are at least a certain specified distance apart. You might want to do t...

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Prune GWAS data in R

March 29, 2011
By
Prune GWAS data in R

Hansong Wang, our biostats professor here at the Hawaii Cancer Center, generously gave me some R code that goes through a SNP annotation file (i.e. a mapfile) and selects SNPs that are at least a certain specified distance apart. You might want to do t...

Read more »

Having a problem with R-2.12.2 64-bit and "gam’ package!

March 17, 2011
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Having a problem with R-2.12.2 64-bit and "gam’ package!

While working with some pitch location data recently, I ran across something strange when using my new computer (with R-2.12.2 64-bit) versus my work computer (with R-2.11.1 x64). Both are 64-bit computers, but I got the new one for portability (it's a laptop) and speed.Anyway, I had been doing some work in the office with Pitch F/X data,...

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Having a problem with R-2.12.2 64-bit and "gam’ package!

March 17, 2011
By
Having a problem with R-2.12.2 64-bit and "gam’ package!

While working with some pitch location data recently, I ran across something strange when using my new computer (with R-2.12.2 64-bit) versus my work computer (with R-2.11.1 x64). Both are 64-bit computers, but I got the new one for portability (it's a laptop) and speed.Anyway, I had been doing some work in the office with Pitch F/X data,...

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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

March 16, 2011
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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

In my last two posts I talked about Ordinary Least Squares, then extended this discussion to the multiple predictor case and briefly talked about some of the problems that may arise. These problems can include omitted variable bias, heteroskedasticity, non-normality, and multicollinearity. Most of these problems are relatively minor in practice and have easy fixes,...

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sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

March 16, 2011
By
sab-R-metrics: Brief Sidetrack for Scatterplot Matrices

In my last two posts I talked about Ordinary Least Squares, then extended this discussion to the multiple predictor case and briefly talked about some of the problems that may arise. These problems can include omitted variable bias, heteroskedasticity, non-normality, and multicollinearity. Most of these problems are relatively minor in practice and have easy fixes,...

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Eigensheep

March 13, 2011
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Eigensheep

Aaron Koblin’s Sheep Market visualization is an awesome use of Mechanical Turk. But it’d be even more awesome if the grid were ordered, so inspired by the use of eigenfaces in facial recognition, I decided to try projecting the sheep … Continue reading →

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R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

February 28, 2011
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R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

When the sample sizes within the levels of our independent variables are not equal, we have to handle our ANOVA differently than in the typical two-way case. This tutorial will demonstrate how to conduct a two-way ANOVA in R when the sample sizes withi...

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R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

February 28, 2011
By
R Tutorial Series: Two-Way ANOVA with Unequal Sample Sizes

When the sample sizes within the levels of our independent variables are not equal, we have to handle our ANOVA differently than in the typical two-way case. This tutorial will demonstrate how to conduct a two-way ANOVA in R when the sample sizes withi...

Read more »

Think academic journals look the same ? Well, some do…

February 8, 2011
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Think academic journals look the same ? Well, some do…

We have seen yesterday that finding an optimal strategy to publish is not that simple. And actually, it can be even more difficult in the case the journal rejects the paper (not because it is not correct, but because "it does not fit" with the stan...

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