the meps household component leads the pack for examining individual-level medical expenditures by payor and type of service. total expenditures captured by the survey tend to be low, but unbiased across the board and can be adjusted to match the...
370 search results for "SQL"
Batch forecasting in R
I sometimes get asked about forecasting many time series automatically. Here is a recent email, for example: I have looked but cannot find any info on generating forecasts on multiple data sets in sequence. I have been using analysis services for sql server to generate fitted time series but it is too much of a black box (or I...
Search and replace: Are you tired of nested `ifelse`?
It happens all the time: you have a vector of fruits and you want to replace all bananas with apples, all oranges with pineapples, and leave all the other fruits as-is, or maybe change them all to figs. The usual solution? A big old nested `ifelse`: ...
Querying an SQLite database from R
You have an SQLite database, perhaps as part of some replication materials, and you want to query it from R. You might want to be able to say: results <- runsql("select * from mytable order by date") and get the results back as an R object. Here's a function to do it. In the following,
100 most read R posts in 2012 (stats from R-bloggers) – big data, visualization, data manipulation, and other languages
Software engineer’s guide to getting started with data science
Many of my software engineer friends ask me about learning data science. There are many articles on this subject from renowned data scientists (Dataspora, Gigaom, Quora, Hilary Mason). This post captures my journey (a software engin...
Opening Large CSV Files in R
Before heading home for the holidays, I had a large data set (1.6 GB with over 1.25 million rows) with columns of text and integers ripped out of the company (Kwelia) Database and put into a .csv file since I was going to be offline a lot over the break. I tried opening the csv file 
Chocolate and nobel prize – a true story?
Few of us can resist chocolate, but the real question is: should we even try to resist it? The image is CC by Tasumi1968.
As a dark chocolate addict I was relieved to see Messerli's ecological study on chocolate consumption and the...
Querying, parsimony and golden hammers
I love it when things are easy. I love it so much that I’ll spend a great deal of time and effort to keep things simple. At the same time, though, I think there’s some value in expending effort in pursuit of something. If you want to understand a thing, you have to spend time 
How to select and merge R data frames with SQL
The R language provides many features in the language for selecting data from data frames: the "[" operator, logical functions, and utility functions like "subset". But if you know SQL (the query language ubiquitous in database systems), none of this is necessary. With the sqldf package, you can just pretend that your data frame is a database, and use...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
