Matt Fidler
@nlmixr2matt.bsky.social
I am one of the lead developers of the nlmixr2 ecosystem and often talk about the items in the nlmixr2 universe.
I'm honored that the nlmixr2 development team received the 2026 Brian Bole Award of Excellence at R in Pharma presented by Open Source in Pharma. rinpharma.com/docs/blog/po...
2026 Brian Bole Award – R/Pharma
2026 The Brian Bole Award of Excellence
rinpharma.com
nlmixr2scm is on CRAN following the same approach as `scm` in PsN: Huge thanks to Justin Wilkins and Yaping Liu, who did most of the work and to everyone who contributed. Post: blog.nlmixr2.org/blog/2026-10... #pharmacometrics #nlmixr2 #rstats #popPK #covariatemodeling
Stepwise covariate modeling with nlmixr2scm | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
New on the Posit blog with Janice Goh: a hands-on intro to pharmacometrics in R. Should a 900 g preterm infant get the same flat phenobarbital dose as a 1.5 kg one? #nlmixr2 #rstats 📝 posit.co/blog/pharmac... 🎥 youtu.be/ZNHOT_AjmYY
Tiny Doses for Tiny Babies -- How much is too much?
posit.co
Your model takes an hour to fit. You change a comment in the script, source it again, and wait another hour. `nlmixr2save` will save you! blog.nlmixr2.org/blog/2026-10... #pharmacometrics #ACoP2026 #rstats #nlmixr2 #PKPD #reproducibility
nlmixr2save: fits you can read, runs you don't repeat | nlmixr2
Portable text-based fits and the := caching operator, on a poster at ACoP 2026
blog.nlmixr2.org
Your report's model diagram and equations should never disagree with the model you ran. - Automatic compartment diagrams with nlmixr2plot's `modelDiagram()`, - LaTeX model equations from nlmixr2extra - nlmixr2rpt 0.2.3 creates them by default blog.nlmixr2.org/blog/2026-09...
Model diagrams and equations, straight from the code | nlmixr2
The figure and the math in your report should never disagree with the model you ran
blog.nlmixr2.org
Some patients don't follow a script, and now your event table doesn't have to either. You put the decision logic in the model block. 📖 Read the post: blog.nlmixr2.org/blog/2026-09... 🎥 Watch the 8-minute narrated walkthrough: youtu.be/kuQbzj5Hm4I
Adaptive dosing in rxode2 | nlmixr2
Some patients don't follow a script — neither should your event table
blog.nlmixr2.org
As a part of the nlmixr2 7.0 release we revamped how we did covariances in hashtag#nlmixr2 hashtag#rstats See our blog for more details: blog.nlmixr2.org/blog/2026-08... Thanks again to Hidde van de Beek for his work on the analytic covariance.
nlmixr2 7.0 is here! focei - Parallel OpenMP threaded solving for faster runs foceif - Exact population gradients for improved stability, precision, and convergence saem - Smaller memory footprint and formal regressor support ... and much more! blog.nlmixr2.org/blog/2026-08...
nlmixr2 7.0 | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
New nlmixr2 blog post: Fitting PK/PD models to published data with admixr2 admixr2 lets you fit PK/PD models to aggregate & published data - digitized mean±SD fits, model data generation via datagen(), and joint MBMA across studies. By H. van de Beek blog.nlmixr2.org/blog/2026-07... #nlmixr2
Fitting PK/PD models to published data with admixr2 | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
One of the things I often get asked is if you can use #nlmixr2 in submissions. We were invited to meet with some of the FDA reviewers, and they confirmed they have received submissions in nlmixr2 and no issues were raised about its use blog.nlmixr2.org/blog/2026-04...
Open Source in Regulatory Review: nlmixr2 Developers Meet Regulators | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
In this month's blog, we announce the ability to have state change properties like f(), alag(), dur(), and rate() in rxode2 5.0.2: blog.nlmixr2.org/blog/2026-03...
I'm excited to announce new integration with the tidyvpc package in nlmixr2. More details about how to use vpcPlot with tidyvpc are included in the blog post: blog.nlmixr2.org/blog/2026-02...
nlmixr2 and tidyvpc | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
Happy New Year! An occasion to celebrate new features; like inter-occasion variability support in nlmixr2! See more details in the blog below. lnkd.in/gizDiPY5
This link will take you to a page that’s not on LinkedIn
lnkd.in
nlmixr2 5.0 is here? Why 5.0 - because a breaking change in the file format of nlmixr2/rxode2 objects. With semantic versioning this means a major release. More details are in our monthly blog: blog.nlmixr2.org/blog/2025-12...
nlmixr2 5.0 | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
The nlmixr2 group is excited that we are joining the R Consortium as a working group! I am grateful for the R community and nlmixr2 community and team members that has made this possible. Join me in celebrating this major milestone in nlmixr2 development history! blog.nlmixr2.org/blog/2025-11...
nlmixr2 is becoming a R Consortium Working Group | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
This month, I'm excited to introduce two new estimation methods in nlmixr2: Laplace (laplace) and adaptive Gaussian Quadrature (agq). blog.nlmixr2.org/blog/2025-10...
New features in #nlmixr2 4.0, a #rstats package include a vere-style loading, importing models from older versions of nlmixr2 and Rstudio bug fixes. See blog.nlmixr2.org/blog/2025-08...
nlmixr2 verse 4.0+ | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
The nlmixr2 team is thrilled to announce the release of nlmixr2 4.0! This major update introduces the WNL linear compartment solutions, replacing the previous ADVAN-based approach for improved accuracy, stability, and compatibility. blog.nlmixr2.org/blog/2025-07...
nlmixr2 4.0 | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
nlmixr2 has an ecosystem around it from researchers and scientists around the world! We celebrate the pharmcometrics community and nlmixr2 community by pointing out integrations between nlmixr2 packages in pharmacometrics. Come join the development! blog.nlmixr2.org/blog/2025-06...
nlmixr2 ecosystem | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org
Do you want to do pharmacometrics with neural network ODEs? You can use nlmixr2 as well as other tools. See this month's blog post: blog.nlmixr2.org/blog/2025-04... #rstats #nlmixr2
nlmixr2 Neural Network ODEs with pmxNODE | nlmixr2
nlmixr: open source nonlinear mixed-effects modeling for R.
blog.nlmixr2.org