Manuel Estévez - 1 year ago 178

C# Question

So I'm trying to use the haversine formula in Unity to get the distance between two different points (latitude and longitud given). The code is working (no errors) but I keep gettting a wrong result. I followed the entire formula so I don't really know where the math/code problem is. Any idea?

Here's the code:

`public float lat1 = 42.239616f;`

public float lat2 = -8.72304f;

public float lon1 = 42.239659f;

public float lon2 = -8.722305f;

void operacion(){

float R = 6371000; // metres

float omega1 = ((lat1/180)*Mathf.PI);

float omega2 = ((lat2/180)*Mathf.PI);

float variacionomega1 = (((lat2 - lat1)/180)*Mathf.PI);

float variacionomega2 = (((lon2 - lon1) / 180) * Mathf.PI);

float a = Mathf.Sin(variacionomega1/2) * Mathf.Sin(variacionomega1/2) +

Mathf.Cos(omega1) * Mathf.Cos(omega2) *

Mathf.Sin(variacionomega2/2) * Mathf.Sin(variacionomega2/2);

float c = 2 * Mathf.Atan2(Mathf.Sqrt(a), Mathf.Sqrt(1-a));

float d = R * c;

}

Answer Source

I think this line is incorrect:

```
float c = 2 * Mathf.Atan2(Mathf.Sqrt(a), Mathf.Sqrt(1-a));
```

**UPDATED:**

The correct way would be:

```
float c = 2 * Mathf.Asin(Mathf.Sqrt(a));
```