Blog Archives

Popup notification from R on Windows

April 17, 2013
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Popup notification from R on Windows

After R is done running a long process, you may need to notify the operator to check the R console and provide the next commands. Without installing any more software or creating any batch files or VBS scripts, here is a simple way to create the popup notice in Windows Continue reading

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lag function for data frames

October 29, 2012
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lag function for data frames

When applying the stats::lag() function to a data frame, you probably expect it will pad the missing time periods with NA, but lag() doesn’t. For example: Nothing happened. Here is an alternative lag function made for this situation. It pads … Continue reading

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nnet2sas() supports centering and scaling

October 4, 2012
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nnet2sas() supports centering and scaling

nnet2sas() version 1 introduced a way to export a nnet() model trained in R to Base SAS through metaprogramming, and now nnet2sas() version 2 introduces support for variable centering and scaling as implemented in caret::train(). See the link for version … Continue reading

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Comparing continuous distributions with R

June 13, 2012
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Comparing continuous distributions with R

In R we’ll generate similar continuous distributions for two groups and give a brief overview of statistical tests and visualizations to compare the groups. Though the fake data are normally distributed, we use methods for various kinds of continuous distributions. … Continue reading

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Plotting individual growth charts

March 14, 2012
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Plotting individual growth charts

This R code draws individual growth plots as shown in “Applied Longitudinal Data Analysis: Modeling Change and Event Occurrence” by Judith D. Singer and John B. Willett, an excellent book on multilevel modeling and survival analysis. This code recreates figure … Continue reading

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Scales and transformations in ggplot2 0.9.0

March 14, 2012
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Scales and transformations in ggplot2 0.9.0

Some R code designed for ggplot2 0.8.9 is not compatible with ggplot2 0.9.0, and today the ggplot2 web site has outdated documentation which gives this broken example: Dennis Murphy points to the ggplot2 0.9.0 transition guide from where I derived … Continue reading

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doSMP removed from CRAN

February 17, 2012
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doSMP removed from CRAN

If you do parallel processing in R on Windows, then you probably have heard of the doSMP package. However, it was recently removed from the CRAN repository with the terse message: Package ‘doSMP’ was removed from the CRAN repository. Revolution … Continue reading

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Using neural network for regression

November 17, 2011
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Using neural network for regression

Artificial neural networks are commonly thought to be used just for classification because of the relationship to logistic regression: neural networks typically use a logistic activation function and output values from 0 to 1 like logistic regression. However, the worth … Continue reading

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Train neural network in R, predict in SAS

November 11, 2011
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Train neural network in R, predict in SAS

This R code fits an artificial neural network in R and generates Base SAS code, so new records can be scored entirely in Base SAS. This is intended to be a simple, elegant, fast solution. You don’t need SAS Enterprise … Continue reading

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Confidence interval diagram in R

October 19, 2011
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Confidence interval diagram in R

This code shows how to easily plot a beautiful confidence interval diagram in R. First, let’s input the raw data. We’ll be making two confidence intervals for two samples of 10. In case you curious, the data represents samples from … Continue reading

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