{"action":"created","issue":{"url":"https://api.github.com/repos/pfnet/chainer/issues/584","labels_url":"https://api.github.com/repos/pfnet/chainer/issues/584/labels{/name}","comments_url":"https://api.github.com/repos/pfnet/chainer/issues/584/comments","events_url":"https://api.github.com/repos/pfnet/chainer/issues/584/events","html_url":"https://github.com/pfnet/chainer/issues/584","id":114430964,"number":584,"title":"Stable SoftmaxCrossEntropy","user":{"login":"bordingj","id":7777521,"avatar_url":"https://avatars.githubusercontent.com/u/7777521?v=3","gravatar_id":"","url":"https://api.github.com/users/bordingj","html_url":"https://github.com/bordingj","followers_url":"https://api.github.com/users/bordingj/followers","following_url":"https://api.github.com/users/bordingj/following{/other_user}","gists_url":"https://api.github.com/users/bordingj/gists{/gist_id}","starred_url":"https://api.github.com/users/bordingj/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bordingj/subscriptions","organizations_url":"https://api.github.com/users/bordingj/orgs","repos_url":"https://api.github.com/users/bordingj/repos","events_url":"https://api.github.com/users/bordingj/events{/privacy}","received_events_url":"https://api.github.com/users/bordingj/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/pfnet/chainer/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-10-31T20:04:26Z","updated_at":"2015-11-02T05:32:07Z","closed_at":null,"body":"The probabilities from the softmax function can become numerically zero. Hence,  for the forward method in the softmax_cross_entropy something like\r\n\r\n \tnumpy.log(numpy.maximum(1.0e-8,p))\r\n\r\nand\r\n\r\n\tlog(fmax(1.0E-8, y[_j * n_channel + t]) ) \r\n\r\nshould be added for the cpu and gpu, respectively."},"comment":{"url":"https://api.github.com/repos/pfnet/chainer/issues/comments/152918622","html_url":"https://github.com/pfnet/chainer/issues/584#issuecomment-152918622","issue_url":"https://api.github.com/repos/pfnet/chainer/issues/584","id":152918622,"user":{"login":"unnonouno","id":740680,"avatar_url":"https://avatars.githubusercontent.com/u/740680?v=3","gravatar_id":"","url":"https://api.github.com/users/unnonouno","html_url":"https://github.com/unnonouno","followers_url":"https://api.github.com/users/unnonouno/followers","following_url":"https://api.github.com/users/unnonouno/following{/other_user}","gists_url":"https://api.github.com/users/unnonouno/gists{/gist_id}","starred_url":"https://api.github.com/users/unnonouno/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/unnonouno/subscriptions","organizations_url":"https://api.github.com/users/unnonouno/orgs","repos_url":"https://api.github.com/users/unnonouno/repos","events_url":"https://api.github.com/users/unnonouno/events{/privacy}","received_events_url":"https://api.github.com/users/unnonouno/received_events","type":"User","site_admin":false},"created_at":"2015-11-02T05:32:07Z","updated_at":"2015-11-02T05:32:07Z","body":"Thank you for reporting a problem.\r\nHow about using `log_sum_exp` to avoid under flow? "}}