{"action":"created","issue":{"url":"https://api.github.com/repos/facebook/react-native/issues/6189","repository_url":"https://api.github.com/repos/facebook/react-native","labels_url":"https://api.github.com/repos/facebook/react-native/issues/6189/labels{/name}","comments_url":"https://api.github.com/repos/facebook/react-native/issues/6189/comments","events_url":"https://api.github.com/repos/facebook/react-native/issues/6189/events","html_url":"https://github.com/facebook/react-native/issues/6189","id":136920900,"number":6189,"title":"[Animation] Get velocity from DecayAnimation","user":{"login":"aleclarson","id":1925840,"avatar_url":"https://avatars.githubusercontent.com/u/1925840?v=3","gravatar_id":"","url":"https://api.github.com/users/aleclarson","html_url":"https://github.com/aleclarson","followers_url":"https://api.github.com/users/aleclarson/followers","following_url":"https://api.github.com/users/aleclarson/following{/other_user}","gists_url":"https://api.github.com/users/aleclarson/gists{/gist_id}","starred_url":"https://api.github.com/users/aleclarson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/aleclarson/subscriptions","organizations_url":"https://api.github.com/users/aleclarson/orgs","repos_url":"https://api.github.com/users/aleclarson/repos","events_url":"https://api.github.com/users/aleclarson/events{/privacy}","received_events_url":"https://api.github.com/users/aleclarson/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/facebook/react-native/labels/Contains%20Potential%20Question%20Keywords","name":"Contains Potential Question Keywords","color":"ededed"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-02-27T13:45:04Z","updated_at":"2016-02-27T13:51:00Z","closed_at":null,"body":"Given the `DecayAnimation`'s deceleration equation:\r\n\r\n```js\r\nvar elapsedTime = Date.now() - this._startTime;\r\nvar value = this._fromValue +\r\n  (this._velocity / (1 - this._deceleration)) *\r\n  (1 - Math.exp(-(1 - this._deceleration) * elapsedTime));\r\n```\r\n\r\nHow can I get the `velocity` given any `elapsedTime`?"},"comment":{"url":"https://api.github.com/repos/facebook/react-native/issues/comments/189642791","html_url":"https://github.com/facebook/react-native/issues/6189#issuecomment-189642791","issue_url":"https://api.github.com/repos/facebook/react-native/issues/6189","id":189642791,"user":{"login":"aleclarson","id":1925840,"avatar_url":"https://avatars.githubusercontent.com/u/1925840?v=3","gravatar_id":"","url":"https://api.github.com/users/aleclarson","html_url":"https://github.com/aleclarson","followers_url":"https://api.github.com/users/aleclarson/followers","following_url":"https://api.github.com/users/aleclarson/following{/other_user}","gists_url":"https://api.github.com/users/aleclarson/gists{/gist_id}","starred_url":"https://api.github.com/users/aleclarson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/aleclarson/subscriptions","organizations_url":"https://api.github.com/users/aleclarson/orgs","repos_url":"https://api.github.com/users/aleclarson/repos","events_url":"https://api.github.com/users/aleclarson/events{/privacy}","received_events_url":"https://api.github.com/users/aleclarson/received_events","type":"User","site_admin":false},"created_at":"2016-02-27T13:51:00Z","updated_at":"2016-02-27T13:51:00Z","body":"Maybe I'm overthinking it and it's as simple as:\r\n\r\n```js\r\nvar velocity = (this.value - this._fromValue) / elapsedTime;\r\n```"}}