---
tags:
    - "Lerp"
    - "Linear"
    - "Step"
    - "Ratio"
    - "Normal"
    - "Normalize"
---

# Inverse Interpolate

[Math](../index.md) / [Algebra](index.md) / **Inverse Interpolate**

<div class="grid cards" markdown>

* :green_circle: Can Read

* :red_circle: Cannot Write

</div>

## Description

Determines where a value lies between two points

## Code

```cs
using System;
using UnityEngine;
using VisualScript.Icons;

namespace VisualScript.Runtime
{
    [Get]
    
    [Title("Inverse Interpolate")]
    [Category("Math/Algebra/Inverse Interpolate")]
    
    [Description("Determines where a value lies between two points")]
    [Image(typeof(IconInterpolate), ColorTheme.Type.Yellow, typeof(BadgeArrowLeft))]
    
    [Keywords("Lerp", "Linear", "Step", "Ratio", "Normal", "Normalize")]
    
    [Serializable]
    public class TypeNumberMathInverseInterpolate : TypeNumber
    {
        private const double Epsilon = float.Epsilon;
        
        [SerializeField] private GetNumber m_Min = new GetNumber();
        [SerializeField] private GetNumber m_Max = new GetNumber();
        
        [SerializeField] private GetNumber m_Value = new GetNumber();
        [SerializeField] private GetBool m_Clamp = new GetBool();

        public override double GetPreview(GameObject source) =>
            InverseLerp(
                this.m_Min.GetPreview(source),
                this.m_Max.GetPreview(source),
                this.m_Value.GetPreview(source),
                this.m_Clamp.GetPreview(source)
            );

        public override double Get(Args args)
        {
            double min = this.m_Min.Get(args);
            double max = this.m_Max.Get(args);

            double value = this.m_Value.Get(args);
            bool clamp = this.m_Clamp.Get(args);
            
            return InverseLerp(min, max, value, clamp);
        }

        private static double InverseLerp(double min, double max, double value, bool clamp)
        {
            double result = Math.Abs(min - max) > Epsilon
                ? (value - min) / (max - min)
                : 0.0;

            return clamp ? Math.Clamp(result, 0.0, 1.0) : result;
        }

        public override string ToString()
        {
            return $"Inverse Lerp between {this.m_Min} to {this.m_Max} for {this.m_Value}";
        }
        
        protected override SubscriptionMode Subscription => SubscriptionMode.OnChange;
    }
}
```