{"action":"created","issue":{"url":"https://api.github.com/repos/chokkan/crfsuite/issues/60","repository_url":"https://api.github.com/repos/chokkan/crfsuite","labels_url":"https://api.github.com/repos/chokkan/crfsuite/issues/60/labels{/name}","comments_url":"https://api.github.com/repos/chokkan/crfsuite/issues/60/comments","events_url":"https://api.github.com/repos/chokkan/crfsuite/issues/60/events","html_url":"https://github.com/chokkan/crfsuite/issues/60","id":131726351,"number":60,"title":"Bias term?","user":{"login":"usptact","id":1818325,"avatar_url":"https://avatars.githubusercontent.com/u/1818325?v=3","gravatar_id":"","url":"https://api.github.com/users/usptact","html_url":"https://github.com/usptact","followers_url":"https://api.github.com/users/usptact/followers","following_url":"https://api.github.com/users/usptact/following{/other_user}","gists_url":"https://api.github.com/users/usptact/gists{/gist_id}","starred_url":"https://api.github.com/users/usptact/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/usptact/subscriptions","organizations_url":"https://api.github.com/users/usptact/orgs","repos_url":"https://api.github.com/users/usptact/repos","events_url":"https://api.github.com/users/usptact/events{/privacy}","received_events_url":"https://api.github.com/users/usptact/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-02-05T19:01:27Z","updated_at":"2016-04-09T06:09:35Z","closed_at":null,"body":"Sometimes I am using the CRFSuite to do document classification. All the features for a document are simply tucked in a single line where the label is the first token in that line as defined by the format.\r\n\r\nIn the classic Logistic Regression setup one tries to fit the model by finding the parameters - theta (number of features x number classes) and a bias term. The CRFSuite gives the former matrix of coefficients but no bias term. Is it necessary for classification?\r\n\r\nAll in all, CRF is just a generalization of Logistic Regression to sequences according to some seminal papers on sequence analysis.\r\n\r\nThanks\r\n"},"comment":{"url":"https://api.github.com/repos/chokkan/crfsuite/issues/comments/207716682","html_url":"https://github.com/chokkan/crfsuite/issues/60#issuecomment-207716682","issue_url":"https://api.github.com/repos/chokkan/crfsuite/issues/60","id":207716682,"user":{"login":"kmike","id":107893,"avatar_url":"https://avatars.githubusercontent.com/u/107893?v=3","gravatar_id":"","url":"https://api.github.com/users/kmike","html_url":"https://github.com/kmike","followers_url":"https://api.github.com/users/kmike/followers","following_url":"https://api.github.com/users/kmike/following{/other_user}","gists_url":"https://api.github.com/users/kmike/gists{/gist_id}","starred_url":"https://api.github.com/users/kmike/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kmike/subscriptions","organizations_url":"https://api.github.com/users/kmike/orgs","repos_url":"https://api.github.com/users/kmike/repos","events_url":"https://api.github.com/users/kmike/events{/privacy}","received_events_url":"https://api.github.com/users/kmike/received_events","type":"User","site_admin":false},"created_at":"2016-04-09T06:09:35Z","updated_at":"2016-04-09T06:09:35Z","body":"@usptact you can add a feature which is 1 for all training examples; it is the same as bias feature. \r\nOne difference is that usually bias is not regularized, but this feature will be regularized like other features. If that's important you can use values like 100 instead of 1, the effect will be similar to not regularizing bias."}}