Installing nwdynam

nwdynam is a separate package (GPL-3) that needs the core nwcommands. Install the core first, then nwdynam.

1. The core

. net install nwcommands, from(https://nwcommands.org/net/) replace
. nwinstall, everything

nwinstall, everything installs the core and all four model packages in one step; nwinstall, all installs the core only.

See Installation & Setup for details, including computers without internet access or administrator rights.

2. nwdynam

. nwinstall, models

If you used nwinstall, everything above, the model packages are already installed; after nwinstall, all (core only) add them with nwinstall, models. Repeating either command updates them. To install nwdynam only, or a specific tagged version, use its own address:

. net install nwdynam, from(https://raw.githubusercontent.com/thomas-u-grund/nwdynam/main/)

(nwinstall, modelpkg(nwdynam) does the same from the core.)

A specific release

Every release is tagged on GitHub and each tag has its own address. For version 1.2.0:

. net install nwdynam, from(https://raw.githubusercontent.com/thomas-u-grund/nwdynam/v1.2.0/) replace

Use a tagged release when you want an analysis to be reproducible: you can then say exactly which version produced the results.

3. Check the installation

. nwdynam version
nwdynam version 1.2.0, 26oct2026
  core package nwcommands : installed (development copy, no distribution date)
  native plugin           : .../d/dynam_sim_macos.plugin (ships with the package, no separate version number)
  compared with           : R goldfish 1.6.12
  license                 : GNU GPL-3

The output shows the release of nwdynam, the core, the native plugin and the version of goldfish that the results were compared with. (The line about the core says “development copy” here because the examples on this website were run from a source checkout; a normal installation shows the distribution date of the core.) The release is stored in r(version), and after a fit in e(version); quote it when you report an analysis. nwversion lists the core and all installed model packages. help nwdynam opens the complete documentation.

Updating

Repeat the net install line with replace. Updating the core never overwrites nwdynam, and updating nwdynam never changes the core. net describe nwdynam shows the installed version and distribution date.

The native plugin

The package ships a compiled plugin for macOS, Linux and Windows. It is installed together with the package and found automatically; nothing needs to be configured. The plugin evaluates the likelihood and its gradient, which the optimizer in Mata calls many times. It serves the three default structural effects of the choice model; other effect sets run in the Mata engine of the package (this is documented in help nwdynam) and give the same results, only more slowly. nwdynam version shows the path of the plugin in use, or “missing” if none is found, in which case everything runs in Mata.

If you have an old copy of nwdynam in Stata’s PLUS folder as well as a new one elsewhere on the ado-path, Stata uses the first one it finds; which nwdynam and nwdynam version show which copy is in use.

Requirements

Stata 17 or later; Stata/BE is enough. Tested with Stata 17 and 18 (the Mata libraries are built with Stata 17, the oldest tested version; Stata 16 and older are untested). The examples on this site used Stata/BE 18.
The core nwcommands, as above. No R and no other software.

Tutorial 1 fits a first model.