{"action":"created","issue":{"url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/28","labels_url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/28/labels{/name}","comments_url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/28/comments","events_url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/28/events","html_url":"https://github.com/trthatcher/MLKernels.jl/issues/28","id":83490791,"number":28,"title":"Limits on parameter ranges: PolynomialKernel,","user":{"login":"st--","id":5763727,"avatar_url":"https://avatars.githubusercontent.com/u/5763727?v=3","gravatar_id":"","url":"https://api.github.com/users/st--","html_url":"https://github.com/st--","followers_url":"https://api.github.com/users/st--/followers","following_url":"https://api.github.com/users/st--/following{/other_user}","gists_url":"https://api.github.com/users/st--/gists{/gist_id}","starred_url":"https://api.github.com/users/st--/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/st--/subscriptions","organizations_url":"https://api.github.com/users/st--/orgs","repos_url":"https://api.github.com/users/st--/repos","events_url":"https://api.github.com/users/st--/events{/privacy}","received_events_url":"https://api.github.com/users/st--/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-06-01T13:20:21Z","updated_at":"2015-06-03T08:36:00Z","closed_at":null,"body":"PolynomialKernel required d to be integer. ExponentialKernel, RationalQuadraticKernel, PowerKernel, LogKernel all require gamma to be <= 1. What's the reason for that ? (Maybe a kernel would not be Mercer if gamma > 1 (or d real, for PolynomialKernel), but it might still be useful. We could just amend ismercer() so that it actually checks the parameter value?)"},"comment":{"url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/comments/108247256","html_url":"https://github.com/trthatcher/MLKernels.jl/issues/28#issuecomment-108247256","issue_url":"https://api.github.com/repos/trthatcher/MLKernels.jl/issues/28","id":108247256,"user":{"login":"st--","id":5763727,"avatar_url":"https://avatars.githubusercontent.com/u/5763727?v=3","gravatar_id":"","url":"https://api.github.com/users/st--","html_url":"https://github.com/st--","followers_url":"https://api.github.com/users/st--/followers","following_url":"https://api.github.com/users/st--/following{/other_user}","gists_url":"https://api.github.com/users/st--/gists{/gist_id}","starred_url":"https://api.github.com/users/st--/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/st--/subscriptions","organizations_url":"https://api.github.com/users/st--/orgs","repos_url":"https://api.github.com/users/st--/repos","events_url":"https://api.github.com/users/st--/events{/privacy}","received_events_url":"https://api.github.com/users/st--/received_events","type":"User","site_admin":false},"created_at":"2015-06-03T08:36:00Z","updated_at":"2015-06-03T08:36:00Z","body":"The finite difference between integer values? e.g. for f'(d=2), (f(d=3)-f(d=1))/2? I don't know how much sense that makes...\r\n\r\nWe can ensure the integrity of *Mercer* kernel types by having ismercer inspect the actual values of the kernel parameters, and e.g. only return true if gamma<=1? But I'm not too fussed about it, we can also just leave it as a hard constraint on the type."}}