Posts

Recoding with case_match and case_when
I wrote previously about recoding characters into numbers using various coding schemes and about recoding numeric values into characters in 2017, where I covered, the recode() function. In this tutorial, I will compare recoding methods with ifelse(), recode(), case_when() and case_match().
2024-02-16 10 min read rstats
Loops
library(tidyverse) library(tictoc) This tutorial will introduce a few ways you can iterate your code. We’ll use the {tictoc} package to time each method to show how they differ. Task specifics Let’s say you want to do a power analysis by simulation.
2022-06-10 9 min read rstats
Data from Images
I saw this a few days ago and sympathised, because I’ve often wanted to use data that is trapped in images or PDFs. If it’s not too much, I’ll manually transcribe it, but that’s so tedious!
Last updated on 2021-10-17 8 min read rstats
Testing for normality
You’ve probably been directed here because you asked someone about how to test the normality of predictors in an analysis. However, statistical tests like t-tests, ANOVAs, and other GLM-based tests assume that the residuals will be normally distributed and it doesn’t matter at all if the predictors and even the dependent variable aren’t.
2021-02-01 8 min read rstats
Experimentum Data Wrangling Demo
(updated 2021-01-21) Experimentum studies require that you download data from questionnaires and experiments separately, since the data have different formats. You can participate anonymously in the demo study (the median completion time is 3.
2021-01-20 17 min read rstats
Function Tips
I see a lot of functions from people new to coding that look like this and I want to point out a few common conceptual mistakes with writing functions.
2020-12-17 8 min read stats
Mann-Whitney False Positives
One of my favourite colleagues, Phil McAleer, asked about unequal sample sizes for Mann-Whitney tests on our group chat today. I had no idea, so, as always, I thought “This is a job for simulations!
2020-09-03 5 min read rstats
How many simulations in my power analysis?
Today I was trying to figure out how to advise on the number of simulations to run when calculating power by simulation. I tackled this question by running a simulation (of course).
2020-08-17 2 min read rstats, simulation
Testing interactive functions
I’m a huge fan of unit tests, but it’s tricky to test interactive functions where the user needs to enter input before the function can progress. I used to test them manually, which is incredibly tedious and time-consuming.
2020-07-31 3 min read rstats
Inputting data table rows as function arguments
I was working on a simulation project with an undergraduate dissertation student today (I’m so amazed at what our students can do now!) and wanted to show her how to efficiently run simulations for all combinations of a range of parameters.
2020-02-06 4 min read rstats