168 search results for "pca"

PCA for NIR Spectra_part 004: "Projections"

February 26, 2012
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PCA for NIR Spectra_part 004: "Projections"

This plot in 2D, help us to decide the number of PCs, it is easy to create in R, once we have discompose the X matrix into a P matrix (loadings) and a T matrix (scores).For this plot, we just need the T matrix.> CPs<-seq(1,10,by=1)>  matp...

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PCA for NIR Spectra_part 003: "NIPALS"

February 25, 2012
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PCA for NIR Spectra_part 003: "NIPALS"

> X<-yarn$NIR> X_nipals<-nipals(X,a=10,it=100)Two matrices are generated (P and T)As in other posts, we are going to look to the loadings & scores, for firsts three principal components:> wavelengths<-seq(1,268,by=1)> matplot(w...

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PCA for NIR Spectra_part 002: "Score planes"

February 23, 2012
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PCA for NIR Spectra_part 002: "Score planes"

The idea of this post is to compare the score plots for the first 3 principal components obtained with the algorithm “svd” with the scores plot of  other chemometric software (Win ISI in this case). Previously I had exported the yarn spectra t...

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Visualization in regression analysis

February 23, 2012
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Visualization in regression analysis

Visualization is a key to success in regression analysis. This is one of the (many) reasons I am also suspicious when I read an article with a quantitative (econometric) analysis without any graph. Consider for instance the following dataset, obtai...

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Maps with R (III)

February 23, 2012
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Maps with R (III)

In my previous posts (1 and 2) I wrote about maps with complex legends but without any kind of interactivity. …

Continuar leyendo »

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Visualization in regression analysis

February 23, 2012
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Visualization in regression analysis

Visualization is a key to success in regression analysis. This is one of the (many) reasons I am also suspicious when I read an article with a quantitative (econometric) analysis without any graph. Consider for instance the following dataset, obtained from http://data.worldbank.org/, with, for each country, the GDP per capita (in some common currency) and the infant mortality rate...

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PCA for NIR Spectra_part 001: "Plotting the loadings"

February 22, 2012
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PCA for NIR Spectra_part 001: "Plotting the loadings"

There are different algorithms to calculate the Principal Components (PCs). Kurt Varmuza & Peter Filzmozer explain  them in their book: “Introduction to Multivariate Statistical Analysis in Chemometrics”.I´m going to apply one of them, to...

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GARCH estimation using maximum likelihood

February 9, 2012
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In my previous post I presented my findings from my finance project under the guidance of Dr Susan Thomas. The results in my paper suggested that there are macroeconomic variables, particularly the INR/USD exchange rates, that help us understand the dynamics of stock returns. Although the results that I obtained were significant at 5%...

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Foreign Currencies and US 10y Treasury Yields

January 17, 2012
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Foreign Currencies and US 10y Treasury Yields

Since I explored the relationship between the Japanese Yen and the US 10y Treasury Yield on Friday, I thought it might be worthwhile to extend the exploration to a much broader range of currencies. I personally am most interested on how Asian Central B...

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New version of analogue (0.8-0)

January 12, 2012
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New version of analogue (0.8-0)

Yesterday I pushed an update of my analogue package to CRAN. The new version is 0.8-0 and contains some new functions, several bug fixes and a major change arising from additions to R 2.14.x requiring all packages to have a … Continue reading

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