René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Logarithmic scale of the y-axis does not work when the range is small","articleBody":"### Bug summary\n\nI have a decreasing function $y\\colon [1,3600] \\to \\mathbb{R}^+$.\nI try to set the logarithmic scale for the y-axis, but if the range of the function is small (i.e., the initial and final value are closeby), then the logarithmic scale does not work and it only prints the linear scale.\n\n\n \n\n### Code for reproduction\n\n```Python\nimport random\n\nimport matplotlib.pyplot as plt\n\n\nT = 3600\nn = 1000\ny_start = 10**4\ny_end = 0.9*y_start\n\nrandom.seed(42)\n# Generate n increasing random values between 1 and T\nx = [random.randrange(1, T) for _ in range(n)]\nx.sort()\n# Generate n decreasing random values between y_start and y_end\ny = [random.uniform(y_end, y_start) for _ in x]\n\ny.sort(reverse=True)\n\nfig, ax = plt.subplots()\nax.set_yscale('log')\nax.plot(x, y)\n\nplt.savefig('step_function.pdf')\n```\n\n### Actual outcome\n\n[step_function.pdf](https://github.com/user-attachments/files/18588250/step_function.pdf)\n\n### Expected outcome\n\nI expected the logarithmis scale. In this example it happens if you set y_end = 0.2*y_start\n\n\n[step_function.pdf](https://github.com/user-attachments/files/18588257/step_function.pdf)\n\n### Additional information\n\n_No response_\n\n### Operating system\n\nLinux debian 6.10.11+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.10.11-1~bpo12+1 (2024-10-03) x86_64 GNU/Linux\n\n\n### Matplotlib Version\n\n3.10.0\n\n### Matplotlib Backend\n\nqtagg\n\n### Python version\n\nPython 3.13.0\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nconda","author":{"url":"https://github.com/TomManMaz","@type":"Person","name":"TomManMaz"},"datePublished":"2025-01-29T13:30:16.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/29544/matplotlib/issues/29544"}