René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Colorbar with log scales wrong format","articleBody":"### Bug summary\n\nThe colour bar ticks are weirdly formatted when using a logarithmic scale when using version 3.5.0 or later.\n\n### Code for reproduction\n\n```python\nTaken from https://matplotlib.org/stable/gallery/images_contours_and_fields/contourf_log.html\r\n\r\n\r\nimport matplotlib.pyplot as plt\r\nimport numpy as np\r\nfrom numpy import ma\r\nfrom matplotlib import ticker, cm\r\n\r\nN = 100\r\nx = np.linspace(-3.0, 3.0, N)\r\ny = np.linspace(-2.0, 2.0, N)\r\n\r\nX, Y = np.meshgrid(x, y)\r\n\r\n# A low hump with a spike coming out.\r\n# Needs to have z/colour axis on a log scale so we see both hump and spike.\r\n# linear scale only shows the spike.\r\nZ1 = np.exp(-X**2 - Y**2)\r\nZ2 = np.exp(-(X * 10)**2 - (Y * 10)**2)\r\nz = Z1 + 50 * Z2\r\n\r\n# Put in some negative values (lower left corner) to cause trouble with logs:\r\nz[:5, :5] = -1\r\n\r\n# The following is not strictly essential, but it will eliminate\r\n# a warning.  Comment it out to see the warning.\r\nz = ma.masked_where(z \u003c= 0, z)\r\n\r\n\r\n# Automatic selection of levels works; setting the\r\n# log locator tells contourf to use a log scale:\r\nfig, ax = plt.subplots()\r\ncs = ax.contourf(X, Y, z, locator=ticker.LogLocator(), cmap=cm.PuBu_r)\r\n\r\ncbar = fig.colorbar(cs)\r\n\r\nplt.show()\n```\n\n\n### Actual outcome\n\n![image](https://user-images.githubusercontent.com/40028739/177347713-40db322e-65a3-4763-af66-8c8bb3daab0c.png)\r\n\n\n### Expected outcome\n\nRunning the exact same code on 3.4.2 produces the expected behaviour\r\n![image](https://user-images.githubusercontent.com/40028739/177347830-9550a81c-7340-49f8-903e-6d39637493f4.png)\r\n\n\n### Additional information\n\nThis worked perfectly on version 3.4.2\n\n### Operating system\n\nWindows\n\n### Matplotlib Version\n\n\u003e3.5.0\n\n### Matplotlib Backend\n\n_No response_\n\n### Python version\n\n_No response_\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\npip","author":{"url":"https://github.com/RemDelaporteMathurin","@type":"Person","name":"RemDelaporteMathurin"},"datePublished":"2022-07-05T14:12:30.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/23389/matplotlib/issues/23389"}