{"action":"created","issue":{"url":"https://api.github.com/repos/librosa/librosa/issues/329","repository_url":"https://api.github.com/repos/librosa/librosa","labels_url":"https://api.github.com/repos/librosa/librosa/issues/329/labels{/name}","comments_url":"https://api.github.com/repos/librosa/librosa/issues/329/comments","events_url":"https://api.github.com/repos/librosa/librosa/issues/329/events","html_url":"https://github.com/librosa/librosa/issues/329","id":150098074,"number":329,"title":"specshow: 'log' frequency scale is not really logarithmic","user":{"login":"sebewert","id":16563070,"avatar_url":"https://avatars.githubusercontent.com/u/16563070?v=3","gravatar_id":"","url":"https://api.github.com/users/sebewert","html_url":"https://github.com/sebewert","followers_url":"https://api.github.com/users/sebewert/followers","following_url":"https://api.github.com/users/sebewert/following{/other_user}","gists_url":"https://api.github.com/users/sebewert/gists{/gist_id}","starred_url":"https://api.github.com/users/sebewert/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/sebewert/subscriptions","organizations_url":"https://api.github.com/users/sebewert/orgs","repos_url":"https://api.github.com/users/sebewert/repos","events_url":"https://api.github.com/users/sebewert/events{/privacy}","received_events_url":"https://api.github.com/users/sebewert/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/librosa/librosa/labels/question","name":"question","color":"cc317c"}],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":5,"created_at":"2016-04-21T14:52:13Z","updated_at":"2016-06-10T13:06:53Z","closed_at":"2016-06-10T13:06:53Z","body":"Hi,\r\nit seems the axis labels shown using specshow with y_axis='log' do not seem to be really logarithmic. For example, using the code snippet below I get a plot with the following equidistant labels: 0, 829.03, 2002.6, 4005.2, 22050\r\n\r\nUnless I am confused right now, this cannot be logarithmic. In particular, log(2 x) = log(2) + log(x)\r\nThat means whenever one value is twice as big as the next one, their difference on the logarithmic scale will be log(2). This is independent of the logarithm base in use. \r\n\r\nThe distance on the logarithmic scale is supposed to be equidistant four all values above. One pair is particularly interesting as  2002.6 * 2 = 4005.2. That means the distance between them gives log(2). The next label above 4005.2, having the same distance on the logarithmic scale, is 22050 and not 8010.4. Unless I misunderstand the docs 'log : the image is displayed on a vertical log scale', that means there might be an issue here somehow.\r\n\r\n```python\r\nfrom __future__ import ( division, absolute_import, print_function, unicode_literals )\r\nimport librosa\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\n\r\nsr=44100\r\ny = np.random.rand(sr*2)\r\n\r\nn_fft = 4096\r\nhop_length = n_fft/4\r\nZ = librosa.core.stft(y, n_fft=n_fft, hop_length=hop_length, center=True)\r\n\r\nplt.figure(figsize=(8,6))\r\nlibrosa.display.specshow(np.abs(Z), sr=sr, hop_length=hop_length, x_axis='time', y_axis='log')\r\n```"},"comment":{"url":"https://api.github.com/repos/librosa/librosa/issues/comments/225176933","html_url":"https://github.com/librosa/librosa/issues/329#issuecomment-225176933","issue_url":"https://api.github.com/repos/librosa/librosa/issues/329","id":225176933,"user":{"login":"bmcfee","id":1190540,"avatar_url":"https://avatars.githubusercontent.com/u/1190540?v=3","gravatar_id":"","url":"https://api.github.com/users/bmcfee","html_url":"https://github.com/bmcfee","followers_url":"https://api.github.com/users/bmcfee/followers","following_url":"https://api.github.com/users/bmcfee/following{/other_user}","gists_url":"https://api.github.com/users/bmcfee/gists{/gist_id}","starred_url":"https://api.github.com/users/bmcfee/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bmcfee/subscriptions","organizations_url":"https://api.github.com/users/bmcfee/orgs","repos_url":"https://api.github.com/users/bmcfee/repos","events_url":"https://api.github.com/users/bmcfee/events{/privacy}","received_events_url":"https://api.github.com/users/bmcfee/received_events","type":"User","site_admin":false},"created_at":"2016-06-10T13:06:53Z","updated_at":"2016-06-10T13:06:53Z","body":"Resolved by merging #368 "}}
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