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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Bar plot of pandas Series requires first index value to be 0","articleBody":"### Bug report\r\n\r\n**Bug summary**\r\n\r\nWhen trying to plot a pandas Series with pyplot.bar(), it seems Series whose first index is not 0 cause a `TypeError: only size-1 arrays can be converted to Python scalars` exception when the `bottom` argument is given. When `bottom` is not given, bar width is not uniform as expected.\r\n\r\n**Code for reproduction**\r\n\r\n\u003c!--A minimum code snippet required to reproduce the bug.\r\nPlease make sure to minimize the number of dependencies required, and provide\r\nany necessary plotted data.\r\nAvoid using threads, as Matplotlib is (explicitly) not thread-safe.--\u003e\r\n\r\n```python\r\nimport pandas as pd\r\nimport matplotlib.pyplot as plt\r\ndf = pd.DataFrame({'i':[1,4,4,4,6,6], 'n':[3,5,1,2,3,4]})\r\n\r\nix = df.index%2 == 0\r\nplt.figure()\r\n# produces expected plot with bars offset from x axis\r\nplt.bar(x=df.loc[ix,'i'], height=df.loc[ix, 'n'], bottom=df.loc[ix, 'i'])\r\nplt.figure()\r\n# produces expected plot\r\nplt.bar(x=df.loc[ix,'i'], height=df.loc[ix, 'n'])\r\n\r\nix = df.index%2 == 1\r\nplt.figure()\r\n# the following fails with `TypeError`\r\n# plt.bar(x=df.loc[ix,'i'], height=df.loc[ix, 'n'], bottom=df.loc[ix, 'i'])\r\n\r\n# converting to a list fixes the issue and produces the expected outcome.\r\n# note that casting both x and bottom to list is required to produce expected outcome.\r\nplt.bar(x=list(df.loc[ix,'i']), height=df.loc[ix, 'n'], bottom=list(df.loc[ix, 'i']))\r\n\r\nplt.figure()\r\n# produces plot with unexpected bar width\r\nplt.bar(x=df.loc[ix,'i'], height=df.loc[ix, 'n'])\r\n\r\n# again, converting to list produces expected outcome\r\nplt.figure()\r\nplt.bar(x=list(df.loc[ix,'i']), height=df.loc[ix, 'n'])\r\n```\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system: macOS 10.15\r\n  * Matplotlib version: 3.1.1\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): MacOSX\r\n  * Python version: 3.6.5\r\n  * Jupyter version (if applicable):\r\n  * Other libraries: pandas 0.25.2\r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\nInstalled from conda, using default channel.\r\n","author":{"url":"https://github.com/zeeMonkeez","@type":"Person","name":"zeeMonkeez"},"datePublished":"2020-02-01T22:45:14.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/16387/matplotlib/issues/16387"}