Publications by jonathanscallahan
How NOT to format time series data
I work with lots of environmental time series data from stationary instruments. This post describes why you should avoid mixing data and metadata in a single file and instead suggests an easy-to-implement, easy-to-use, maximally compact format consisting of two .csv files linked by unique identifiers. EPA Air Quality System The world of air qualit...
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Systematic error messages
Anyone writing code for use in data processing systems needs to have a well thought-out protocol for generating error messages and logs. When a complex pipeline breaks, good logs and recognizable error messages are key to debugging the problem. This post describes improvements to the MazamaCoreUtils package that help you create systematic error...
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Basic Error Handing in R with tryCatch()
The R language definition section on Exception Handling describes a very few basics about exceptions in R but is of little use to anyone trying to write robust code that can recover gracefully in the face of errors. In fact, if you do a little searching you will find that quite a few people have read through the ?tryCatch documentation but co...
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Easier Error Handling in R with try()
In a previous post, we looked at error handling in R with the tryCatch() function and how this could be used to write Java style try-catch-finally blocks. This time we’ll look at what can be done with the try() function and how we can easily process warning and error messages to take appropriate action when something goes wrong. The try() func...
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Standard Latitudes and Longitudes
What? Where? When? These are key questions that every scientist or other collector of environmental data must answer. What is the value of the thing we are measuring?Where are we taking the measurement?When are we taking the measurement? In a previous post we discussed how to standardize “when”. But what about “where”? It shoul...
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When is a number not a number?
Have you ever asked yourself whether your telephone number is really a number? It’s got numbers in it but does it measure anything? How about your credit card number? PO Box? Social Security Number? Zip code? What would happen if you subtracted one of these from another? As it turns out, many of the “numbers” we deal with every day ...
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MazamaSpatialUtils R package
Version 0.7 of the MazamaSpatialUtils is now available on CRAN and includes an expanded suite of spatial datasets with even greater cleanup and harmonization than in previous versions. If your work involves environmental monitoring of any kind, this package may be of use. Here is the description: A suite of conversion functions to create interna...
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