{"id":3392,"date":"2023-03-06T20:00:00","date_gmt":"2023-03-06T11:00:00","guid":{"rendered":"https:\/\/python-academia.com\/en\/?p=3392"},"modified":"2023-07-02T15:00:37","modified_gmt":"2023-07-02T06:00:37","slug":"matplotlib-legend","status":"publish","type":"post","link":"https:\/\/python-academia.com\/en\/matplotlib-legend\/","title":{"rendered":"[matplotlib]How to Add Legend"},"content":{"rendered":"\n

This article shows how to add a legend<\/span> for a graph in matplotlib.<\/p>\n\n\n\n

<\/i>Contents<\/span><\/p>

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<\/p>\n\n\n\n

  • How to add legend<\/li>
  • How to display the legend horizontally<\/li>
  • How to change the legend position<\/li>
  • How to place the legend outside of the plot<\/li>
  • How to change legend font size<\/li>
  • How to change legend font<\/li><\/ul>\n\n\n\n

    <\/p>\n<\/div><\/div>\n\n\n\n

    <\/div>\n\n\n\n

    First, I will show you how to add a legend as a basic introduction.<\/p>\n\n\n\n

    After that, I will show you how to adjust the details of a legend, such as how to specify the position and change the font size.<\/p>\n\n\n\n

    <\/div>\n\n\n\n

    How to add legend<\/h2>\n\n\n\n

    In the beginning, I show how to add legend<\/span>.<\/p>\n\n\n\n

    <\/div>\n\n\n\n

    The following two ways are explained below.<\/p>\n\n\n\n

    • Using “label” in plot function<\/li>
    • Using “legend function”<\/li><\/ul>\n\n\n\n
      <\/div>\n\n\n\n

      Using “label” in plot function<\/h3>\n\n\n\n

      I show how to add the legend using “label” in plot function<\/span>.<\/p>\n\n\n\n

      <\/div>\n\n\n\n

      In the plot function, you can specify the legend string by using the “label” argument.<\/p>\n\n\n\n

      This is the example code.<\/p>\n\n\n\n

      import numpy as np\nimport matplotlib.pyplot as plt\n\n\nx = np.linspace(0, 10, 100)\n\ny1 = np.sin(x)\ny2 = np.cos(x)\n\n\nfig = plt.figure(figsize = (6,6), facecolor='lightblue')\nax1 = fig.add_subplot(1, 1, 1)\n\nax1.plot(x, y1, linestyle='solid', marker='o', label='sin')\nax1.plot(x, y2, linestyle='solid', marker='o', label='cos')\n\nax1.set_xlabel('X')\nax1.set_ylabel('Y')\n\nax1.legend()\n\nplt.show()<\/code><\/pre>\n\n\n\n
      <\/div>\n\n\n\n
      The above code generates the following graph.<\/p>\n\n\n
      \n
      \"\"<\/figure><\/div>\n\n\n
      <\/div>\n\n\n\n
      > ax1.plot(x, y1, linestyle=’solid’, marker=’o’, label=’sin’)<\/p>\n\n\n\n
      label=’sin’   :    Specify a string to be displayed as a legend.<\/p>\n\n\n\n
      <\/div>\n\n\n\n
      ax1.legend( )<\/p>\n\n\n\n
      Add the legend using legend function.<\/p>\n\n\n\n
      <\/div>\n\n\n\n
      Using “legend function”<\/h3>\n\n\n\n
      I show how to add the legend using “legend function”<\/span>.<\/p>\n\n\n\n
      <\/div>\n\n\n\n
      This is the example code.<\/p>\n\n\n\n
      import numpy as np\nimport matplotlib.pyplot as plt\n\n\nx = np.linspace(0, 10, 100)\n\ny1 = np.sin(x)\ny2 = np.cos(x)\n\n\nfig = plt.figure(figsize = (6,6), facecolor='lightblue')\nax1 = fig.add_subplot(1, 1, 1)\n\nax1.plot(x, y1, linestyle='solid', marker='o')\nax1.plot(x, y2, linestyle='solid', marker='o')\n\nax1.set_xlabel('X')\nax1.set_ylabel('Y')\n\nax1.legend(['sin', 'cos'])\n\nplt.show()<\/code><\/pre>\n\n\n\n
      <\/div>\n\n\n\n
      The above code generates the following graph. (The same graph in the section above.)<\/p>\n\n\n
      \n
      \"\"<\/figure><\/div>\n\n\n
      <\/div>\n\n\n\n
      > ax1.legend([‘sin’, ‘cos’])<\/p>\n\n\n\n
      Specify a string to be displayed as a legend.<\/p>\n\n\n\n
      <\/div>\n\n\n\n
      sponsored link<\/p>\n\n\n\n\n
      \n