{"action":"created","issue":{"url":"https://api.github.com/repos/gap-packages/Semigroups/issues/205","repository_url":"https://api.github.com/repos/gap-packages/Semigroups","labels_url":"https://api.github.com/repos/gap-packages/Semigroups/issues/205/labels{/name}","comments_url":"https://api.github.com/repos/gap-packages/Semigroups/issues/205/comments","events_url":"https://api.github.com/repos/gap-packages/Semigroups/issues/205/events","html_url":"https://github.com/gap-packages/Semigroups/pull/205","id":171711863,"number":205,"title":"Introduce IndexAndPeriod, and related functions","user":{"login":"wilfwilson","id":8956868,"avatar_url":"https://avatars.githubusercontent.com/u/8956868?v=3","gravatar_id":"","url":"https://api.github.com/users/wilfwilson","html_url":"https://github.com/wilfwilson","followers_url":"https://api.github.com/users/wilfwilson/followers","following_url":"https://api.github.com/users/wilfwilson/following{/other_user}","gists_url":"https://api.github.com/users/wilfwilson/gists{/gist_id}","starred_url":"https://api.github.com/users/wilfwilson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wilfwilson/subscriptions","organizations_url":"https://api.github.com/users/wilfwilson/orgs","repos_url":"https://api.github.com/users/wilfwilson/repos","events_url":"https://api.github.com/users/wilfwilson/events{/privacy}","received_events_url":"https://api.github.com/users/wilfwilson/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":7,"created_at":"2016-08-17T17:14:37Z","updated_at":"2016-08-18T18:09:51Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/gap-packages/Semigroups/pulls/205","html_url":"https://github.com/gap-packages/Semigroups/pull/205","diff_url":"https://github.com/gap-packages/Semigroups/pull/205.diff","patch_url":"https://github.com/gap-packages/Semigroups/pull/205.patch"},"body":"This PR introduces a new function `IndexAndPeriod` which calculates the index and the period of an arbitrary semigroup element. Previously, functions only existed for transformations and partial perms. I have added a special method which works for elements which have a rank function, which includes bipartitions. There are tests and documentation for the new code.\r\n\r\nAdditionally, for monogenic semigroups or monoids, the size of the semigroup can be calculated from the index and the period of the generator. Therefore I have installed methods to calculate the size of monogenic semigroups/monoids (with known minimal generating sets) which use this fact."},"comment":{"url":"https://api.github.com/repos/gap-packages/Semigroups/issues/comments/240807679","html_url":"https://github.com/gap-packages/Semigroups/pull/205#issuecomment-240807679","issue_url":"https://api.github.com/repos/gap-packages/Semigroups/issues/205","id":240807679,"user":{"login":"wilfwilson","id":8956868,"avatar_url":"https://avatars.githubusercontent.com/u/8956868?v=3","gravatar_id":"","url":"https://api.github.com/users/wilfwilson","html_url":"https://github.com/wilfwilson","followers_url":"https://api.github.com/users/wilfwilson/followers","following_url":"https://api.github.com/users/wilfwilson/following{/other_user}","gists_url":"https://api.github.com/users/wilfwilson/gists{/gist_id}","starred_url":"https://api.github.com/users/wilfwilson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wilfwilson/subscriptions","organizations_url":"https://api.github.com/users/wilfwilson/orgs","repos_url":"https://api.github.com/users/wilfwilson/repos","events_url":"https://api.github.com/users/wilfwilson/events{/privacy}","received_events_url":"https://api.github.com/users/wilfwilson/received_events","type":"User","site_admin":false},"created_at":"2016-08-18T18:09:51Z","updated_at":"2016-08-18T18:09:51Z","body":"@james-d-mitchell The operation is now called `IndexPeriodOfSemigroupElement` and the method installed for matrices over finite fields uses the rank method."}}
{"actor":{"display_login":"wilfwilson"}}