Two-Gene Network Simulation using Unity

// Computational Medicine
// Two-Gene Network Simulation using Unity
// Yong-Jun Shin (2019)

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CellScript : MonoBehaviour
{
    float x;        // x protein concentration in uM (scalar)
    float y;        // y protein concentration in uM (scalar)
    float Pxy;      // production parameter
    float Py;       // degradation parameter
    float r;        // red color intensity representing y protein concentration (0 - 1)
    float yMax;     // maximal y protein concentration in uM

    // Start is called before the first frame update
    void Start()
    {
        Pxy = 0.8f;
        Py = 0.95f;
        x = 10.0f;    // constanx x protein concentration (= 10 uM)
        y = 0.0f;     // initial y protein concentration (= 0 uM)
        yMax = 2 * Pxy * x / (1 - Py);  // assume yMax equals 2 times steady state level
    }

    // FixedUpdate is called once per frame.
    // 0.02 seconds (50 calls per second) is the default time between calls.
    void FixedUpdate()
    {
        Time.fixedDeltaTime = 0.05f;  // the time interval in seconds at which physics and other fixed
                                     // fixed frame updates are performed.
        y = Pxy * x + Py * y;  // difference equation
        r = y / yMax;          // compute r
        GetComponent<Renderer>().material.color = new Color(r, 0, 0); // update the red color intensity
        Debug.Log("y: " + y);  // display y value in the Unity console window
        Debug.Log("r: " + r);  // display r value in the Unity console window
    }
}