Comments (1)
Hi,
As far as I know there's no article that describe exactly the same calculations. However, several articles use the general formulas of the generalized least squares estimator to get variance of the treatment effect. My calculations are described in the package's technical vignette:.
As you note, there exists several different definitions of both the variance ratio and the standardized effects. Tho, they make no difference for the actual calculations, but they do lead to different raw values. Currently, I use calculations that are more common in my field (clinical psychology). My plan is to add other definitions as well. I the mean time it should be possible to simply enter the corresponding variance components, and avoid using my standardizations. Though, this is not the best solution as you'd have to manually translate the treatment effect to the same units as my definition. The next release will, at least, include the possibility to use unstandardized value for the time:treatment-interaction, which will make custom definitions more easy. And I should probably make this more clear in the documentation.
I suspect the differences to PASS is either caused by the models not being exactly the same, or differences in the degrees of freedom / distribution used when doing the power analysis. Many other implementations simply use normal approximations, and avoid the issue of correct dfs.
Thanks for the feedback!
from powerlmm.
Related Issues (16)
- Simulate results HOT 1
- Simulating continous predictors at given level
- Feature request: Generate multilevel data with no clusters HOT 3
- uneven time between observations HOT 1
- FEATURE REQUEST: R code from shiny app
- Shiny App: 2-level design gives NaN% Power
- Use a study setup to calculate power for t-test/ANCOVA
- dev version of installation error (... non-zero exit status) HOT 1
- Allow comparison of more than two models when simulating
- Availability for R version 3.6.1 HOT 2
- An issue with powerlmm - error message Error in prettyNum(.Internal(format(x, trim, digits, nsmall, width, 3L, : invalid value 0 for 'digits' argument HOT 1
- Power for moderators (time:treatment:moderator interaction)
- Allow crossed designs HOT 1
- simulate: Bug when a parameter is NA, but the term is still included in model formula
- simulate: satterthwaite dfs give error when time:treatment is omitted
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from powerlmm.