---
title: "force(fromValue:toValue:position:velocity:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/spring/force(fromvalue:tovalue:position:velocity:)"
---

# force(fromValue:toValue:position:velocity:)

Calculates the force upon the spring given a current position, velocity, and divisor from the starting and end values for the spring to travel.

## Declaration

```swift
func force<V>(fromValue: V, toValue: V, position: V, velocity: V) -> V where V : Animatable
```

## Discussion

Discussion This value is in units of the vector type per second squared.

## See Also

### Calculating forces and durations

- [force(target:position:velocity:)](swiftui/spring/force(target:position:velocity:).md)
- [settlingDuration(target:initialVelocity:epsilon:)](swiftui/spring/settlingduration(target:initialvelocity:epsilon:).md)
- [settlingDuration(fromValue:toValue:initialVelocity:epsilon:)](swiftui/spring/settlingduration(fromvalue:tovalue:initialvelocity:epsilon:).md)