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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...
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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...
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100% stacked bar chart in SAS’s SGPLOT
A 100% stacked bar chart is useful for comparing the relative frequencies of an m x n table where frequencies in m are very different. While this is easy to do in Excel, SAS requires an extra step,...
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Word could not create the work file. Check the temp environment variable
Encrypting the Microsoft Windows temporary folder causes Microsoft Outlook 2010 to not open Word file attachments because of these “cryptic” errors: Word could not create the work file. Check the temp...
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Using SQLObject with Microsoft SQL Server and Windows Authentication
Here is how to use Windows Authentication to connect to Microsoft SQL Server with SQLObject. Continue reading →
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Outlook: Trying to Connect
This is how I solved a problem of Microsoft Outlook 2010 "Trying to Connect" for several days. Continue reading →
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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...
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Geolocate IP addresses in R
This R function uses the free freegeoip.net geocoding service to resolve an IP address (or a vector of them) into country, region, city, zip, latitude, longitude, area and metro codes. Continue reading →
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Calculate RMSE and MAE in R and SAS
Here is code to calculate RMSE and MAE in R and SAS. RMSE (root mean squared error), also called RMSD (root mean squared deviation), and MAE (mean absolute error) are both used to evaluate models. MAE...
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Get free disk space in SAS on Windows
This SAS macro retrieves the amount of free disk space, and puts the value in the SAS log and in a global macro variable. It works with local and remote drives and mapped and UNC paths. To avoid data...
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Bar plot with error bars in R
Here's a simple way to make a bar plot with error bars three ways: standard deviation, standard error of the mean, and a 95% confidence interval. The key step is to precalculate the statistics for...
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Binomial confidence intervals: exact vs. approximate
This graph and R code compares the exact vs. normal approximations for 95% binomial confidence intervals for n trials with either one success or 50% success. Continue reading →
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Practical MD5 in SAS
This guide introduces MD5 and hash functions in general, lists common uses for hash functions, gives advise on how to best use MD5 in SAS, and covers common issues.
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Blog moved to Blogger.com
After five years and 405,557 page views on WordPress.com, I will now be posting from http://heuristicandrew.blogspot.com/. Please update any bookmarks, RSS feeds, or Atom feeds. New Atom feed for all...
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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,...
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