Categorized as "R"

As an impatient person, I typically use progress bars for any code that takes more than a few minutes to run. In a previous post, I wrote about creating ASCII progress bars in R and Racket.

One of the advantages of open source software is being able to view, review, and learn from source code. Both R and Chez Scheme provide tools for accessing source code.

I have previously written about how to read and write JSON files in R and Racket. In re-reading that old post, I’m struck by how it shows me tinkering without understanding.

I was reading a blog post that mentioned that Julia has “[w]eak conventions about namespace pollution” and it got me thinking about how I manage namespace pollution in R and Chez Scheme.

In the process of learning Chez Scheme, I’ve missed R’s ability to quickly pull up documentation from the console via help or ?. I’ve toyed with the idea of trying to format the contents of the Chez Scheme User’s Guide for display in the REPL (similar to Clojure Docs).

In a previous post, I used GUI toolkits to make progress bars in R and Racket. However, I usually prefer the ASCII progress bars of the progress package in R.

As an impatient person and an insecure programmer, I typically use progress bars for any code that takes more than a few minutes to run. In R, a progress bar widget is available through the tcltk package.

In learning about reading CSV files in Racket, I have started to reconsider whether storing small(ish) datasets in CSV files is the best default behavior.1 My default was set by primarily working in R, where reading and writing CSV files plays a central role in data analysis.

In a previous post, I wrote about reading and writing data to file while retaining the structure and attributes of the data (i.e., data serialization). However, I more commonly pass data around as text files (usually, CSV files).

One of the areas of expertise at Cramer Fish Sciences is watershed and habitat restoration. In the context of that work, we are often faced with estimating how much rearing habitat is needed to support a specified number of juvenile salmonids (or how many juvenile salmonids are supported by a specified amount of rearing habitat).

In a previous post, I wrote a function to perform repeated timings of untyped and typed versions of the same Racket functions. #lang racket (require math) (define (time-apply-cpu-old proc lst reps) (define out (for/list ([i (in-range reps)]) (define-values (results cpu-time real-time gc-time) (time-apply proc lst)) cpu-time)) (displayln (string-append "min: " (number->string (apply min out)) " mean: " (number->string (round (mean out))) " max: " (number->string (apply max out)) " function: " (symbol->string (object-name proc))))) time-apply-cpu-old is a wrapper function for time-apply from racket/base that runs time-apply repeatedly and prints the min, mean, and max cpu time.

In a previous post, I wrote that Racket’s if is similar to ifelse in R. That’s not quite right. This is a short post to clarify the comparison. The more accurate description is that this Racket code

On my journey to learn Racket, I look for small pieces of R code to try to implement in Racket. A blog post about speeding up population simulations in R with the Rcpp package seemed like a good candidate for implementing in Racket.

R makes it easy to generate random numbers from a wide variety of distributions with a consistent interface. For example, runif, rnorm, and rpois generate random numbers from uniform, normal, and Poisson distributions, respectively.

When programming in R, I generally pass data around by reading and writing text files (typically, CSV files). The ubiquity of CSV files means that many different types of software will open them easily (e.

The Delta Simulation Model II (DSM2) is a hydrodynamic model used for Sacramento-San Joaquin Delta planning and management. When working with DSM2 output, I frequently need to look up the location of channels, nodes, and stations in the model.

When building a simulation model in R, I might want to group related input parameters into a data structure. For example, in a life cycle model with resident and anadromous fish, you might use different fecundity parameters for each life history type.

I have recently started learning Racket. For a first task, I tried to build a simple age-structured population model. I hit a stumbling block and reached out to the helpful folks on the Racket mailing list.

Shiny Scorekeeper is a basketball scorekeeper app built with the Shiny web framework for R. I’ve written about the motivation for creating Shiny Scorekeeper on my projects page. The short version is that I needed a new app for scoring video of my son’s basketball games and I decided it would be a good learning experience to try to build my own.

UPDATE (2020-09-06): The approach described below is fragile and I no longer use it. Here are a couple of alternatives: electricShine and photon. In developing the DSM2 HYDRO Viz Tool, we were faced with deciding how to deploy a Shiny app that required interaction with large local files.