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Korado is a CLI application for linear optimizations that mimics the syntax of LINDO, a popular optimization modeling language. Korado stands for "Koray's Operations Research App for Decision Optimization". Koray is my middle name, and it does sound cool in the title, therefore being in it.

The purpose of this tool is to provide a LINDO-like optimization tool for any OS. I first started this basic app after I realized that there wasn't a LINDO for MacOS, and the alternative, LINGO, was not user-friendly. I wanted to create a simple, more easily usable and accessible alternative.

Features

• LINDO Syntax Compatibility: Supports the core components of the LINDO modeling language:
  • Objective functions: MAXIMIZE (or MAX) and MINIMIZE (or MIN).
  • SUBJECT TO (or ST, S.T., SUCH THAT) section for constraints.
  • END statement to conclude the model definition.
  • Comment lines starting with !.
  • Constraint labels (e.g., ROW1)).
• Post-END Declarations: Handles common variable specifications placed after the END statement:
  • FREE: Unrestricted variables.
  • GIN: General integer variables.
  • INT: Binary integer variables (0 or 1).
  • SLB: Simple Lower Bounds.
  • SUB: Simple Upper Bounds.
  • TITLE: A title for the model.
• Interactive Editor: Provides a simple, full-screen text editor (powered by curses) for composing and editing models directly in the terminal.
• Standard Solver Backend: Uses the robust and widely-used PuLP modeling library with the CBC (COIN-OR Branch and Cut) solver.
• Clear Output: Presents the solution, including the objective function value, variable values, and binding constraints, in a clean, readable format.

Installation

1. Clone the repository:

   git clone https://github.com/batukoray/Korado.git
   cd Korado

2. Create a virtual environment (recommended):

   python3 -m venv .venv
   source .venv/bin/activate

3. Install the required packages:

   pip install -r requirements.txt

   This will install pulp, which automatically includes the CBC solver.

Usage

Run the script from your terminal:

python3 korado.py

This will launch the interactive editor.

In the Editor

• Navigate: Use the arrow keys (↑, ↓, ←, →), Home, and End to move the cursor.
• Edit: Type to insert characters. Use Backspace and Delete to remove them.
• New Line: Press Enter to create a new line.
• Solve: Press Ctrl+G to solve the model.
• Quit: Press Ctrl+Q to exit the program.

Example

The script includes a built-in example. To run it directly, use the --example flag:

python3 korado.py --example

This will immediately solve the following model and print the solution:

MIN 50 X1 + 100 X2
ST
7 X1 + 2 X2 >= 28
2 X1 + 12 X2 >= 24
END

How It Works

1. Input: The tool accepts a multi-line string formatted according to LINDO syntax.
2. Parsing: A series of regular expressions and parsing functions break down the input text into its core components:
   • The optimization sense (MAX or MIN).
   • The objective function expression.
   • A list of constraints, each with a left-hand side, an operator (<=, >=, =), and a right-hand side.
   • Any post-END declarations for variable types and bounds.
3. Model Formulation: The parsed specification is used to build an optimization problem object using the pulp library. LpVariable objects are created with the appropriate bounds and categories (Continuous, Integer, or Binary).
4. Solving: The problem is passed to the CBC solver.
5. Output: The solver's results (status, objective value, variable values, and constraint slack) are formatted and printed to the console.

Dependencies

• PuLP: A popular open-source linear programming modeler for Python.
• CBC (COIN-OR Branch and Cut): A high-performance open-source mixed-integer programming solver that is included with PuLP.

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This tool is for educational and simulation purposes and is not an official product of LINDO Systems Inc.