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
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
What's wrong with aggregating data?
Shiny app for a face-rating example. library(tidyverse) library(lmerTest) set.seed(90210) Imagine you want to find out if Armenian women born on an even-numbered day are taller than women born on an odd-numbered day.
2019-03-04 7 min read rstats
Simulating Random Slopes
This tutorial has been moved to the tutorials section.
2019-01-09 1 min read rstats
Simulate from Existing Data
library(faux) library(tidyverse) I added a new function to the package faux to generate a new dataframe from an existing dataframe, simulating all numeric columns from normal distributions with the same mean and SD as the existing data and the same correlation structure as the existing data.
2018-12-29 2 min read rstats