René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Severe bug in ``imshow`` when plotting images with small values","articleBody":"The following minimal example:\n\n```\nimport matplotlib\nmatplotlib.use('Agg')\nfrom astropy.wcs import WCS\nfrom wcsaxes import datasets\nimport matplotlib.pyplot as plt\nhdu = datasets.fetch_msx_hdu()\nplt.imshow(hdu.data, vmin=-2e-4, vmax=2e-4)\nplt.savefig('image.png')\n```\n\nproduces the following output:\n\n![image](https://cloud.githubusercontent.com/assets/314716/15148599/dedc6636-16bd-11e6-83f8-a06d4c5f5757.png)\n\nThis appears to be related to the fact the values in the image data are \u003c 1. If I multiply all the values by 1e6, I get something sensible:\n\n```\nplt.imshow(hdu.data * 1e6, vmin=-2e-4, vmax=2e-4)\nplt.savefig('image.png')\n```\n\n![image](https://cloud.githubusercontent.com/assets/314716/15148648/26fd7162-16be-11e6-84b9-347e388d99f2.png)\n","author":{"url":"https://github.com/astrofrog","@type":"Person","name":"astrofrog"},"datePublished":"2016-05-10T13:48:38.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/6394/matplotlib/issues/6394"}