gmpl-tex 0.1.1

Convert GMPL (GNU MathProg) models into LaTeX.

gmpl-tex

Convert GMPL (GNU MathProg) optimization models into LaTeX, so the sets, parameters, variables, constraints and objectives you wrote for a solver can go straight into a paper with readable, renamed symbols.

Either way you use it, the tool works in two phases so you stay in control of the notation:

1. Lookup table - every name in the model is collected into a table, where each raw name maps to a label you can edit.
2. LaTeX generation - the model is rendered to LaTeX using your edited labels.

There are two front-ends:

• gmpl-tex-web - a local web app: paste or drop a model, rename labels, and watch the LaTeX render live. Best for interactive work.
• gmpl-tex - a command-line tool: a scriptable two-step (JSON table → LaTeX) for batch use.

Requirements

• Python 3.10 or newer. Check what you have:
  • Windows: py --version
  • macOS / Linux: python3 --version
  • If it's missing, install from python.org. On Windows, tick "Add python.exe to PATH" in the installer.
• lark and nicegui
  • installed automatically.

Install

pip install gmpl-tex

One install gives you both front-ends: the gmpl-tex command line and the gmpl-tex-web UI.

Windows: use py -m pip install gmpl-tex if pip isn't on your PATH.

---

Web UI

gmpl-tex-web          # opens http://localhost:8080 in your browser
gmpl-tex-web 9000     # ... on a different port

The app runs only on your machine - nothing is uploaded or reachable from the network. Closing the terminal stops it.

How to use it:

1. Add your model - paste GMPL into the editor on the left, or drop / click to upload a .mod file.
2. Rename labels - in the middle lookup table, each row maps a raw name to the label you want in the output. Edits apply instantly. The section tabs (Sets, Parameters, Variables, Constraints, Objectives) filter the view.
3. Take the LaTeX - on the right, List shows each statement rendered; expand a card to edit or copy that single line. Tex shows the full document to copy or download. Both follow the active section tab.

The three panes: model editor (left), editable lookup table (middle), live preview (right).

Editing a label in the lookup table updates the rendered statement immediately.

The Tex tab shows the full LaTeX document, ready to copy or download.

---

Command line

gmpl-tex model.mod [lookup.json] --json
gmpl-tex model.mod [lookup.json] [output.tex] --latex

1. Generate the editable lookup table (writes model.json)

gmpl-tex model.mod --json

For a model like

set I;
param d{i in I} >= 0;
var x{i in I} >= 0;
s.t. demand{i in I}: x[i] >= d[i];
minimize cost: sum{i in I} x[i];

model.json is:

{
    "sets":        { "I": "I" },
    "parameters":  { "d": "d" },
    "variables":   { "x": "x" },
    "constraints": { "demand": "demand" },
    "objectives":  { "cost": "cost" }
}

2. Edit the labels you want to rename

// Example: rename "cost" to "c"
{
    ...
    "objectives":  { "cost": "c" }
}

3. Render LaTeX using your edited labels (writes model.tex)

gmpl-tex model.mod model.json --latex

Note: If you skip step 1 and run gmpl-tex model.mod --latex directly, a default table is created automatically (labels equal to the raw names) and used. An existing model.json next to the model is reused as-is and never overwritten.

An example model is included under examples/model.mod.

(Not sure which front-end you have? Run gmpl-tex --help or gmpl-tex-web --help - each points you to the other.)

Troubleshooting

• Double subscript on LaTeX compile: LaTeX rejects multiple _ in a symbol. The converter will happily emit them, but LaTeX throws a Double subscript error. Remove the extra _ from the label (in the lookup table or the JSON) and re-render.
• A symbol shows up in red: that name has no label - it's missing from the lookup table. This mainly happens with a hand-edited model.json (CLI); add the missing entry and re-run.

License

MIT - see LICENSE.