Build Status Codecov test coverage Github commits cran version Monthly Downloads Total Downloads Rdoc DOI License

Road map, and Tutorials (let me know what you’d like, or perhaps a book?)

umx is a package designed to make structural equation modeling easier, from building, to modifying and reporting.


If you use it, you should cite: Timothy C. Bates, Michael C. Neale, Hermine H. Maes, (2019). umx: A library for Structural Equation and Twin Modelling in R. Twin Research and Human Genetics, 22, 27-41. DOI:10.1017/thg.2019.2

umx includes high-level functions for complex models such as multi-group twin models, as well as graphical model output.

Install it from CRAN:


Most functions have extensive and practical examples (even figures for the twin models): so USE THE HELP :-).

See what is on offer with ‘?umx’. There are online tutorials at

umx stands for “user” OpenMx functions. It provides over 100 functions, but most importantly:

  1. umxRAM that makes path-based SEM in R straightforward and plot for graphically display of your model.
  2. A suite of twin modelling functions.

These are supported by dozens of low-level functions automating activities such as labeling, setting start values etc., and helping with data-wrangling, plotting etc.

Some highlights include:

  1. Building Path Models
  2. Reporting output
  3. Modify models
  4. Twin modeling!
  5. Easy-to-remember options
  6. Many more miscellaneous helpers e.g.

Feel free to use, and submit code and requests via Github. Tell your friends! Publish more good science :-)

For thrill-seekers and collaborators only: the bleeding-edge development version is here: