# JS API Reference

# Welcome to the Highcharts JS Options Reference

These pages outline the chart configuration options, and the methods and properties of Highcharts objects.

Feel free to search this API through the search bar or the navigation tree in the sidebar.

# plotOptions.packedbubble.layoutAlgorithm.parentNodeOptions.integration

Integration type. Available options are `'euler'` and `'verlet'`. Integration determines how forces are applied on particles. In Euler integration, force is applied direct as `newPosition += velocity;`. In Verlet integration, new position is based on a previous posittion without velocity: `newPosition += previousPosition - newPosition`.

Note that different integrations give different results as forces are different.

In Highcharts v7.0.x only `'euler'` integration was supported.