{"action":"created","issue":{"url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/1","repository_url":"https://api.github.com/repos/MolSSI/tensor-interfaces","labels_url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/1/labels{/name}","comments_url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/1/comments","events_url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/1/events","html_url":"https://github.com/MolSSI/tensor-interfaces/issues/1","id":279437651,"number":1,"title":"Tensor terminology","user":{"login":"devinamatthews","id":5246113,"avatar_url":"https://avatars2.githubusercontent.com/u/5246113?v=4","gravatar_id":"","url":"https://api.github.com/users/devinamatthews","html_url":"https://github.com/devinamatthews","followers_url":"https://api.github.com/users/devinamatthews/followers","following_url":"https://api.github.com/users/devinamatthews/following{/other_user}","gists_url":"https://api.github.com/users/devinamatthews/gists{/gist_id}","starred_url":"https://api.github.com/users/devinamatthews/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/devinamatthews/subscriptions","organizations_url":"https://api.github.com/users/devinamatthews/orgs","repos_url":"https://api.github.com/users/devinamatthews/repos","events_url":"https://api.github.com/users/devinamatthews/events{/privacy}","received_events_url":"https://api.github.com/users/devinamatthews/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":30,"created_at":"2017-12-05T16:20:57Z","updated_at":"2018-04-09T16:27:58Z","closed_at":"2018-04-09T16:27:58Z","author_association":"COLLABORATOR","body":"Let's discuss and decide on some terminology to use consistently **for dense tensors**:\r\n\r\n1) A tensor which is addressed by *n* indices is:\r\n    - [ ] a: *n*-dimensional\r\n    - [ ] b: *n*-mode\r\n    - [x] c: order-*n*\r\n    - [ ] d: rank-*n*\r\n    - [ ] e: *n*-way\r\n    - [ ] f: *n*-adic\r\n    - [ ] g: *n*-fold\r\n    - [ ] h: *n*-index\r\n\r\n2) The tensor A[ijkl] has four:\r\n    - [ ] a: dimensions\r\n    - [x] b: modes\r\n    - [ ] c: ranks\r\n    - [ ] d: indices\r\n    - [ ] e: ways\r\n    - [ ] f: subspaces\r\n\r\n3) The number of distinct values that *i* can have in A[ijkl] is the first:\r\n    - [ ] a: length\r\n    - [x] b: extent\r\n    - [ ] c: dimension\r\n\r\n3) The ordered set of extents (3.) (one for each mode (2.)) is the:\r\n    - [x] a: shape\r\n    - [ ] b: size\r\n    - [ ] c: structure\r\n\r\n4) *i*, *j*, *k*, and *l* in A[ijkl] are:\r\n    - [x] a: 0-based\r\n    - [ ] b: 1-based\r\n\r\n5) *i* in A[ijkl] is a(n):\r\n    - [x] a: index\r\n    - [ ] b: label\r\n\r\n6) The operation B[jkli] <- A[ijkl] is a:\r\n    - [ ] a: tensor transpose\r\n    - [x] b: mode permutation\r\n    - [ ] c: reshaping\r\n    - [ ] d: shuffle\r\n\r\n7) The operation B[jkli] <- A[ijkl] can be denoted in shorthand as:\r\n    - [x] a: (1,2,3,0) \"comes-from\"\r\n    - [ ] b: (3,0,1,2) \"goes-to\"\r\n\r\n8) In the operation C[ijkn] <- A[ijlmn] * B[lmkn], *l* and *m* are:\r\n    - [x] a: contracted\r\n    - [ ] b: internal\r\n    - [ ] c: bound\r\n\r\n9) ...and *i*, *j*, *k*, and *n* are:\r\n    - [x] a: uncontracted\r\n    - [ ] b: external\r\n    - [ ] c: free"},"comment":{"url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/comments/379812100","html_url":"https://github.com/MolSSI/tensor-interfaces/issues/1#issuecomment-379812100","issue_url":"https://api.github.com/repos/MolSSI/tensor-interfaces/issues/1","id":379812100,"user":{"login":"devinamatthews","id":5246113,"avatar_url":"https://avatars2.githubusercontent.com/u/5246113?v=4","gravatar_id":"","url":"https://api.github.com/users/devinamatthews","html_url":"https://github.com/devinamatthews","followers_url":"https://api.github.com/users/devinamatthews/followers","following_url":"https://api.github.com/users/devinamatthews/following{/other_user}","gists_url":"https://api.github.com/users/devinamatthews/gists{/gist_id}","starred_url":"https://api.github.com/users/devinamatthews/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/devinamatthews/subscriptions","organizations_url":"https://api.github.com/users/devinamatthews/orgs","repos_url":"https://api.github.com/users/devinamatthews/repos","events_url":"https://api.github.com/users/devinamatthews/events{/privacy}","received_events_url":"https://api.github.com/users/devinamatthews/received_events","type":"User","site_admin":false},"created_at":"2018-04-09T16:27:58Z","updated_at":"2018-04-09T16:27:58Z","author_association":"COLLABORATOR","body":"I've updated the issue to reflect what seems to be the least problematic set of \"canonical\" terms. Of course, as long as we have a translation table then everyone can stay on the same page. I have avoided \"dimension\" in any usage since it is so heavily overloaded, and also tried to avoid using \"index\" for two different concepts (the \"slot\" in the tensor and what label that slot is given).\r\n\r\nI will be updating the wiki page on terminology to reflect this discussion and provide a translation table of terms. Then, I suggest moving on to working on a basic low-level tensor contraction interface."}}
{"actor":{"display_login":"devinamatthews"}}