Notes from a data witch

A blog by Danielle Navarro

Hidden link used to verify my account on fosstodon.org Hidden link used to verify my account on genart.social Hidden link used to verify my account on hachyderm.io

Quirky tiling of the plane in black and white

The trouble with ‘ntile()’
R
Data Wrangling
Statistics

Please, please, please do not use ‘dplyr::ntile()’ in an analysis that will be submitted to a regulatory agency. It’s secretly an ill-conceived SQL tool that doesn’t do what…

Danielle Navarro
Sep 20, 2026

Boxes. Lots of boxes.

Release: sessioncheck 0.2
R
Reproducibility
Package Release

In which the author realises she doesn’t know how to write package release posts

Danielle Navarro
Sep 13, 2026

Rainbow coloured umbrellas

Separating sex and gender is statistical malpractice
Statistics
LGBTQIA+

The 2020 ABS standard for collecting sex and gender data is almost never the right approach outside the context it was designed for, and its spread into medicine and other…

Danielle Navarro
Aug 6, 2026

A close up view of a print of a woman's face

A cocaine skeptic starts an unwise habit
LLMs

You will be shocked to learn that this is not actually a post about cocaine

Danielle Navarro
Jul 26, 2026

Abstract art

Markdown styling in R plots and tables
R
Data Visualisation
Data Wrangling

There is very little novelty in this one, but it helps me to have it written down somewhere

Danielle Navarro
Jul 3, 2026

A laptop on fire

Some thoughts on checking the R session
R
Reproducibility
Package Release

More precisely, some thoughts on an R package I might send to CRAN, and I’d appreciate comments and criticism

Danielle Navarro
Jan 6, 2026

Photograph of Sydney downtown taken from a distant beach

Mapping runkeeper data
R
Data Visualisation
Data Wrangling

Wherein the author attempts to convince herself that she hasn’t just been imagining things

Danielle Navarro
Jan 5, 2026

Artwork depicting two faces blended together

Two githubs, one laptop
Git

Some notes on managing multiple sets of github credentials on the one machine

Danielle Navarro
Dec 8, 2025

Picture of weights

Some notes on survey weights
Statistics
Surveys

An area of statistics in which the author is not strong, and really needs to up her game

Danielle Navarro
Sep 27, 2025

A book carved into the shape of a gun

Some notes on probability judgement
Statistics
Psychology
LGBTQIA+

For the love of fuck, literally nobody thinks that 20% of the population is transgender. Please stop sharing that ridiculous YouGov statistic

Danielle Navarro
Sep 21, 2025

Rectangle themed art with a subdued palette

Linear cosine palettes
Art
R

Kind of a generative art thing, but mostly an attempt by the author to prove to herself that a she can write a short blog post without turning it into a goddamn monograph

Danielle Navarro
Sep 14, 2025

Agnes and Enid dancing, from the TV show Wednesday

GAMLSS, NHANES, and my own personal hell
Statistics
R

Fiiiiiiinally she writes the cursed GAMLSS post. Oh and it’s also about the NHANES data set I guess

Danielle Navarro
Sep 7, 2025

A black cat looking disapproving

Splines, B-splines, P-splines, and a disapproving kitten
Statistics
R

No, I do not care about splines. But I am trying to learn about GAMLSS regression, and yes, it is to this dark place that this topic has taken me

Danielle Navarro
Sep 6, 2025

Lucille Bluth confessing her disdain for the Box-Cox power exponential

The Box-Cox power exponential distribution
Statistics
R

This is so obviously a prequel post to something else that I want to write about GAMLSS models

Danielle Navarro
Aug 2, 2025

Diego Luna. Because he is very pretty

Generating quarto syntax within R
Quarto
Literate Programming
R
Package Release

To quote Cassian Andor, “It’s harder than it looks”

Danielle Navarro
Jul 5, 2025

Abstract generative art in a blue, red, orange and purple palette

Bayesian Emax regression using brms
R
Pharmacometrics
Statistics
Bayes
Stan

A little bit like the book chapters, except with fewer details about things you care about, and several weird digressions that nobody will love

Danielle Navarro
Jun 14, 2025

An unlabelled scatterplot matrix with convex hull annotations

Scatterplot matrices with pairwise pivoting
R
Data Visualisation
Data Wrangling

As with so many things in life, something that I used to think was infuriatingly difficult and cumbersome turns out to be really easy if you just format the data properly

Danielle Navarro
Jun 3, 2025

A pair of squares being affine transformed so often that wildness ensues

When good pseudorandom numbers go bad
R
Reproducibility
Statistics

Multivariate normal sampling can be wildly irreproducible if you’re not careful. Sometimes more than others. There are eldritch horrors, ill-conditioned matrices, and…

Danielle Navarro
May 18, 2025

Red heart against a green background

Making menacing hearts
Art
LGBTQIA+

In which the author calls the little mermaid a whore

Danielle Navarro
Apr 17, 2025

A dartboard with a dart on the bullseye

Three short stories about targets
R
Reproducibility
Parallel Computing
Blogging
Literate Programming

In which our intrepid adventurer turns a hacky data visualisation exercise into an analysis pipeline; builds an R blog with litedown and targets; and tries to wrap her head…

Danielle Navarro
Jan 8, 2025

Dragon picture on the cover of the D&D basic rules, a.k.a. 'The Red Box'

The schools of magic
R
Data Visualisation
Tidy Tuesday

Code and explanations for a Tidy Tuesday data visualisation exercise

Danielle Navarro
Jan 1, 2025

A stylised tree image, white against black background in one half and black on white in the other

Art from code VII: Pixel filters
R
Art

An introduction to the ggfx package. Some weirdly distorted images are created. Good times are had by all concerned

Danielle Navarro
Dec 24, 2024

An irregular quasi-tiling of pastel coloured rectangles against a white background

Art from code VI: Tiles and tessellations
R
Art

There are a lot of rectangles in this post. Also some foolishness with voronoi tessellations I guess

Danielle Navarro
Dec 23, 2024

Textured generative art with grainy box shapes in yellow and blue against a dark background

Art from code V: Iterated function systems
R
Art

A deep dive into the fractal flame algorithm, an egregious coding error, and a lot more C++ than I would prefer to be writing

Danielle Navarro
Dec 22, 2024

Unreal looking landscape in bright colours

Art from code IV: Shading tricks
R
Art

Let’s be honest, this entire post is a thinly-veiled excuse to play around and do terrible things with the rayshader package

Danielle Navarro
Dec 21, 2024

Smudged hexagons in red, yellow, and blue against a dark background

Art from code III: Polygon tricks
R
Art

It’s almost offensive how much you can do with 500 nearly-transparent polygons

Danielle Navarro
Dec 20, 2024

Fractal noise pattern that looks like white clouds against a teal sky

Art from code II. Spatial tricks with ambient
R
Art

Fun and games with spatial noise patterns, courtesy of the ambient package

Danielle Navarro
Dec 19, 2024

Segmented brown, white, and black arcs arranged in a circular pattern against a dark background

Art from code I: Generative art with R
R
Art

An act of wholesale, unapologetic theft. In which the author discusses the core logic of generative art, and (ab)uses the ggplot2 package for her own ungodly purposes

Danielle Navarro
Dec 18, 2024

Four women dancing

Baby got backreferences
R
Regular Expressions

Now I have \2 problems

Danielle Navarro
Dec 16, 2024

Worm on a string meme

Bézier curve
R
Art
Worms

What sins will she commit?

Danielle Navarro
Nov 24, 2024

Bayesian estimation for Emax regression
R
Pharmacometrics
Bayes
Statistics
Stan

In which the author sighs a lot

Danielle Navarro
Nov 11, 2024

For fs
R
Command Line

Let’s be honest… I wrote this post because I wanted an excuse to be sweary. But I guess it’s also a post about interacting with the file system in R

Danielle Navarro
Oct 6, 2024

Cover art to 'Use of Weapons' by Iain M. Banks

Use of flextable
R
Data Wrangling

In which the author explores the flextable R package for table construction, and gushes far too much about the work of Iain M. Banks

Danielle Navarro
Jul 4, 2024

Screenshot to the film clip for 'Make Me Wanna Die' by The Pretty Reckless, in which Taylor Momsen is looking fabulous

Making tables in R with table1
R
Data Wrangling

A pretty reckless dive into a package that hits the sweet spot for me

Danielle Navarro
Jun 21, 2024

Cover art to 'Sirius' by Olaf Stapledon, showing a dog with electrodes on its head

Plotting data in Julia
Julia
Data Visualisation

Part three of this three-part series of Julia posts, in which I try to figure out how to draw some nice plots

Danielle Navarro
Mar 3, 2024

Mass Effect 2 fan art showing the silhouette of the illusive man

Working with data in Julia
Julia
Data Wrangling

Part two of a three-part series on Julia, in which the author teaches herself the basics of wrangling rectangular data in Julia

Danielle Navarro
Mar 2, 2024

Screenshot from the TV show Foundation with two figures above an ocean

A foundation in Julia
Julia

Part one of a three-part series in which I swear I was going to keep it brief but ended up writing a staggeringly long set of notes on learning a bit of Julia

Danielle Navarro
Mar 1, 2024

Rainbow coloured horizontally aligned blobs

Creating new generative art tools in R with grid, ambient, and S7
R
Object-Oriented Programming
Grid Graphics
Art
LGBTQIA+

There might be a darker undercurrent in this one

Danielle Navarro
Feb 25, 2024

Swirling generative art in orange, red, black and pink

Splatter
Art
R

How to make a mess with ggplot2 and ambient

Danielle Navarro
Jan 26, 2024

Water droplets on a surface

Notes on the Emax model
Pharmacometrics

A post that is little more than notes-to-self, on a model I want to make sure I understand

Danielle Navarro
Jan 9, 2024

Generative art

Making generative art with observable.js
Javascript
Art
Observable

I’ve used observable.js before, but this time around I actually tried to understand how it works

Danielle Navarro
Jan 9, 2024

Photo of brightly coloured yarn

Writing knitr hooks
R
Literate Programming

Customising knitr output with hook functions is a handy skill, and I can never quite remember it when I need to, so here’s a blog post to remind myself

Danielle Navarro
Dec 30, 2023

Screenshot from the video clip to 'Houdini' by Dua Lipa

Fine-grained control of RNG seeds in R
R
Randomness

In which the author was trying to fuck a spider but ended up shaving a yak with a fabulous Dua Lipa soundtrack in the background

Danielle Navarro
Dec 27, 2023

17th century etching of 'Theseus and Ariadne', by Stefano Della Bella

The blogdown of theseus
Javascript
R
Blogging
Literate Programming

Because you know what? I am here to fuck spiders

Danielle Navarro
Dec 23, 2023

Grey and yellow photo of stairs with multiplication formulas depicted on the steps

Closed form solutions for a two-compartment pharmacokinetic model
Pharmacometrics

There are times when you simply have to derive a thing yourself in order to understand it, even if no-one else cares

Danielle Navarro
Dec 19, 2023

Abstract geometric patterns in red and orange

Another year ends
End of Year

Some say the year ends in fire, some say in ice. As to my own desire, any end at all will be nice.

Danielle Navarro
Dec 16, 2023

Greyscale photo of a woman (Lizzo) striking a magnificent pose in front of a brick wall with musical notation painted on it

Pharmacometric simulation with rxode2
R
Pharmacometrics

Basically the same post as the last one. It’s a brief introduction to pharmacometric simulation, but this time I’m using rxode2 instead of mrgsolve

Danielle Navarro
Aug 28, 2023

Pink and blue pill against a blue background

Pharmacometric simulation with mrgsolve
R
Pharmacometrics

Yet another post in the ever-expanding series where Danielle teaches herself pharmacometric modelling, which I’m certain is thrilling to everyone

Danielle Navarro
Aug 14, 2023

Cover art to Paul Simon's 1975 single '50 ways to leave your lover'

Four ways to write assertion checks in R
R

It’s not 50 ways to leave your lover, but spend enough time talking about assertive programming in the bedroom and you’ll only have 49 more to discover

Danielle Navarro
Aug 8, 2023

Hand-drawn scientific diagram from 1937 showing 'blood circulation', 'tissue boundaries', and adding pharamacometric notation

Getting started with Torsten
R
Stan
Torsten
Pharmacometrics

Another small step along the path to Bayesian pharmacometrics

Danielle Navarro
Jul 15, 2023

The Death of Julius Caesar (1806) by Vincenzo Camuccini. A painting depicting, yes, the assassination of Julius Caesar.

Beware the IDEs of Windows (Subsystem for Linux)
Linux
R

Setting up nice developer environments on a Windows / Ubuntu-for-WSL system with the help of RStudio Server and the VS Code WSL extension

Danielle Navarro
Jul 2, 2023

Stylised art showing a balrog riding a dragon. The piece is called 'Gothmog at the Storming of Gondolin', and is CC-BY licenced by Tom Loback

Makefiles. Or, the balrog and the submersible
Reproducibility

Fly, you fools!

Danielle Navarro
Jun 30, 2023

Photo of many small white tables in an outdoor courtyard

Extracting tables from pdf files with tabulizer
R
Data Wrangling

Something nicer than the last post

Danielle Navarro
Jun 16, 2023

A map of the United States with arrows showing movement across states

On living in dark times
R
Statistics
LGBTQIA+

Estimating the number internally displaced transgender people in the United States.

Danielle Navarro
Jun 15, 2023

The LGBT rainbow flag

A little ANSI trickery
R
LGBTQIA+

Fun and games with asciicast and cli. There’s really not much to this one except a little bit of personal entertainment

Danielle Navarro
Jun 14, 2023

An image showing two pieces of paper pinned to a board

Pins and needles
R
Reproducibility

Learning my lessons the hard way

Danielle Navarro
Jun 12, 2023

A photo of numerous pills and capsules in many different colours

Building a population pharmacokinetic model with Stan
Statistics
Pharmacometrics
R
Stan
NONMEM
Bayes

In which the author works her way through the first part of an online tutorial, rewrites some NONMEM code in Stan, and takes notes

Danielle Navarro
Jun 10, 2023

Book cover for 'Software Design by Example'

Software design by example
Software Design
Javascript
R
Regular Expressions

A book review, sort of. Not really. Look, Greg sent me a copy and I had fun reading it. okay?

Danielle Navarro
May 31, 2023

Hex sticker image for the santoku R package

Santoku
R
Data Wrangling

On the small joys of clean, single-purpose R packages.

Danielle Navarro
May 22, 2023

Colourful photo of many pills and tablets

Pharmacokinetic ODE models in Stan
Statistics
Pharmacometrics
Stan
Bayes
MCMC
R

A discussion of one- and two-compartment pharmacokinetic models with model implementations in Stan, covering both first-order dynamics and Michaelis-Menten kinetics.

Danielle Navarro
May 16, 2023

Many white pills shown against a blue background

Non-compartmental analysis
Statistics
Pharmacometrics
R

A heavily oversimplified discussion of a simple pharmacokinetic tool, written as an exercise in teaching myself something new. Learning new things is always fun

Danielle Navarro
Apr 26, 2023

Katy Perry in a wedding dress, looking apprehensive

A personal essay on Bayes factors
Statistics
Bayes

In which the dead return to life and the author has opinions

Danielle Navarro
Apr 12, 2023

Promotional image for the film 'Metropolis'

The Metropolis-Hastings algorithm
Statistics
MCMC

A note that I wrote for a computer science class I taught all the way back in 2010

Danielle Navarro
Apr 12, 2023

Pixellated image of black, white, and grey tiles

How to run R code in the browser with webR
R
WebR

In which the author gets unreasonably excited about a new thing

Danielle Navarro
Apr 9, 2023

Spiralling squares and circles in blue, pink, and white

Generative art with grid
Art
R
Grid Graphics
LGBTQIA+

I decided it was time to learn more about the grid package in R, and so naturally used it to make generative art

Danielle Navarro
Mar 31, 2023

Generative art that looks a little like a topographic map of a coastline

Shattered landscapes
Art
R

Using ambient and rayshader to create weird, broken landcape images in R

Danielle Navarro
Mar 13, 2023

A donut shape in brown and white with many criss-crossing lines inside

Fun and games with p5.js and observable.js in quarto
Art
P5
Observable
Javascript
Quarto

Okay it’s a short post in which I teach myself a bit of p5.js, but it does have five different donut examples which seems cool?

Danielle Navarro
Jan 14, 2023

Many tan and white squares arranged in concentric circles against an orange background

Deploying R with kubernetes
R
Docker
Kubernetes
Plumber

In which it is painfully clear that the author is trying to figure it all out as she goes

Danielle Navarro
Jan 10, 2023

A 4x4 grid of cartoon whales, all in the style of the Docker logo

Playing with docker and the github container registry
Linux
R
Docker

In which the author learns how to use docker and, in her usual fashion, goes a little bit overboard. But there are also generative art whales, so that’s nice.

Danielle Navarro
Jan 1, 2023

The Arch Linux logo rendered as ASCII art

btw I use Arch now
Linux
R

There is no reason for this.

Danielle Navarro
Dec 31, 2022

Soft pastel hexagons in a blurry watercolour style

A very strange year
End of Year

A wrap up of my 2022. Even by the standards of the recent past this has been a very weird year for me. A lot has happened, both professionally and personally. I’m still…

Danielle Navarro
Dec 26, 2022

Many blue and yellow rectangles arranged in concentric circles

Queue
Parallel Computing
R
Object-Oriented Programming

It is a truth universally acknowledged, that a post about multithreading must be in want of an async trick

Danielle Navarro
Dec 22, 2022

Grids of coloured blocks in a vaguely rainbow-like ordering

Crayola crayon colours
R
Data Wrangling
Data Visualisation

Am I bored in the house? Yes. And am I in the house bored? Also yes. But do I have rvest and a stubborn desire not to allow the horrors of ‘data encoded in the CSS style’ to…

Danielle Navarro
Dec 18, 2022

An irregular tiling of rectangles in red, green, and brown.

Unpacking Arrow Datasets
Apache Arrow
R

A comment on how Datasets work in Apache Arrow. I’m not really sure who the audience for this one. Am I just talking to myself? Probably.

Danielle Navarro
Nov 30, 2022

A greyscale image of a mammoth

Everything I know about Mastodon
Mastodon
Social Media

A hastily written guide for data science folks trying to navigate the fediverse.

Danielle Navarro
Nov 3, 2022

Image of a biplane flying towards clouds

Building an Arrow Flight server
Apache Arrow
Networking
R
Python

A step by step walkthrough introducing the reader to Arrow Flight, with examples in R and Python

Danielle Navarro
Oct 18, 2022

Screenshot from an old news paper. Text reads 'The Arrow hits the mark'

Data transfer between Python and R with rpy2 and Apache Arrow
Apache Arrow
R
Python

A Pythonic approach for sharing Arrow Tables between Python and R. This is the second in a two-part series on data transfer. In this post I discuss how the rpy2 Python…

Danielle Navarro
Sep 16, 2022

Close-up of scales on a reticulated python

Passing Arrow data between R and Python with reticulate
Apache Arrow
R
Python

In a multi-language ‘polyglot’ data science world, it becomes important that we are able to pass large data sets efficiently from one language to another without making…

Danielle Navarro
Sep 9, 2022

Image of six open face sandwiches

Sudo ask me a password
Linux
Credentials
R

Resolving a little quirk in managing packages with pak on linux

Danielle Navarro
Sep 4, 2022

Data visualisation that looks like a street map of New York City

How to visualise a billion rows of data in R with Apache Arrow
Apache Arrow
Data Visualisation
R

In which the author grapples with the awkward question of what data visualisation really means when you have a staggering amount of data to work with

Danielle Navarro
Aug 23, 2022

Image of a woman dancing surrounded by tables

Arrays and tables in Arrow
Apache Arrow
R

In which the author discusses arrays, chunked arrays, record batches, tables, and datasets in the R interface to Apache Arrow. Masochism is mentioned, and the music of…

Danielle Navarro
May 25, 2022

A laptop, with a small jug and book adjacent to it

Porting a distill blog to quarto
Quarto
Blogging
Reproducibility
Literate Programming

I have moved this blog from distill over to quarto, and taken notes. A year after starting the blog, this promises to be an interesting reproducibility test

Danielle Navarro
Apr 20, 2022

Photo of dried grass

Using Amazon S3 with R
Amazon S3
R

Somehow I was convinced that using Amazon S3 would be a supremely difficult thing to learn, kind of like learning git and GitHub for the first time. Thankfully, it’s…

Danielle Navarro
Mar 17, 2022

Abstract generative art in red and black

Data types in Arrow and R
Apache Arrow
R

A post describing fundamental data types in R and Apache Arrow, and how data is exchanged between the two systems. It covers conversion of logicals, integers, floats…

Danielle Navarro
Mar 4, 2022

Photo of a phone displaying the twitter logo crossed out

R scripts for twitter mutes and blocks
Twitter
R
Social Media

Social media safety tools like muting and blocking are often misused, but for people who are targeted for harassment they are powerful and important. This is a brief…

Danielle Navarro
Feb 11, 2022

Photo of the cast of The Magicians

Binding Apache Arrow to R
Apache Arrow
R

I’ve been learning how to program with Apache Arrow inside R, and also I have been watching the SyFy show “The Magicians” obsessively. For no sensible reason I wrote a blog…

Danielle Navarro
Jan 18, 2022

Photo of some cranberries spilling out of a glass jar

Setting CRAN repository options
R

A quick post on how to use RStudio public package manager instead of a standard CRAN mirror, and an example of why that can be useful sometimes.

Danielle Navarro
Jan 10, 2022

Green lit signage showing white arrows

Getting started with Apache Arrow
Apache Arrow
R

I’ve been wanting to learn the basics of Apache Arrow a while: this is the story of how an R user learned to stop worrying and love a standardised in-memory columnar data…

Danielle Navarro
Nov 19, 2021

Woman holding a gun

Data serialisation in R
Serialisation
R

A terrifying descent into madness, or, an explanation of how R serialises an in-memory data structure to summon a sequence of bytes that can be saved or transmitted.…

Danielle Navarro
Nov 15, 2021

Abstract generative art with concentric jagged polygons

Unpredictable paintings
Art
R

An example showing how to build a generative art system in R. The post walks through some of the creative and design choices that are involved, and highlights how much of a…

Danielle Navarro
Nov 1, 2021

Generative art that looks like several stylised trees

Generative art resources in R
Art
R

An extremely incomplete (and probably biased) list of resources to help an aspiring generative artist get started making pretty pictures in R

Danielle Navarro
Oct 19, 2021

Abstract generative art in black and white

How to mint digital art on HEN
Art

Not every artist wants to make cryptoart, and that’s okay. Others do, and that’s okay too. But if you want to try it out in a socially responsible way, it takes a bit of…

Danielle Navarro
Sep 26, 2021

Photo of Britney Spears performing

Visualising the hits of Queen Britney
Tidy Tuesday
Data Visualisation
R

A gentle walkthrough of a few data wrangling and visualisation tools using the Billboard 100 data for this weeks Tidy Tuesday. Pitched at beginners looking to refresh their…

Danielle Navarro
Sep 14, 2021

Flowing generative art that looks a little like jasmine flowers

Art, jasmines, and the water colours
Art
R

An essay and tutorial covering a few useful art techniques in R

Danielle Navarro
Sep 7, 2021

Keys hanging from colourful lego-block keyholder

Managing GitHub credentials from R, difficulty level linux
Git
Credentials
Linux
R

A sick sad story in which a humble R user was forced to learn something about how linux stores passwords and, more importantly, got R to use her GitHub credentials properly

Danielle Navarro
Aug 8, 2021

Generative art with swirly yellow hearts against a red background

Generative art in R
Art
R

Comments on an exhibit I contributed to as part of useR!2021

Danielle Navarro
Jul 8, 2021

Cartoon hearts on a grid of rectangles

Bootstrap cards in distill
Blogging
Bootstrap
Distill
R

How to enable bootstrap 4 on a distill website, even though you probably don’t need to. I like it though because I get to add pretty bootstrap cards

Danielle Navarro
Apr 19, 2021

Photo of a page with handwriting repeating 'I must not tell lies'

Pretty little CLIs
Command Line
R

How to make a gorgeous command line interface in R using the cli package. Somewhere along the way I accidentally learned about ANSI control codes, which strikes me as…

Danielle Navarro
Apr 18, 2021

Generative art that looks like a blueish bunch of flowers

Welcome to the jungle
Blogging
Reproducibility
Distill

I have reluctantly decided to create a new blog. Some thoughts on what I hope to achieve, having tried my hand at blogging so very many times before

Danielle Navarro
Apr 5, 2021
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