2024-02-01-annotation-log-axis.html

---
name: Annotations with Log Axes
language: plotly_js
suite: annotations
order: 3.5
sitemap: false
arrangement: horizontal
markdown_content: |
  If the `x` or `y` positions of an annotation reference a log axis, you need to provide that position as a `log10` value when adding the annotation. In this example, the `yaxis` is a log axis so we pass the `log10` value of `1000` to the annotation's `y` position.
---
var dates = [
    "2024-01-01",
    "2024-01-02",
    "2024-01-03",
    "2024-01-04",
    "2024-01-05",
    "2024-01-06",
];

var y_values = [1, 30, 70, 100, 1000, 10000000];

var trace1 = {
    x: dates,
    y: y_values,
    mode: 'lines+markers',
    type: 'scatter'
};

var layout = {
    yaxis: {
        type: 'log',
    },
    annotations: [
        {
            x: '2024-01-05',
            y: Math.log10(1000),
            text: 'Log axis annotation',
            showarrow: true,
            xanchor: 'right',
        }
    ]
};

var data = [trace1];

Plotly.newPlot('myDiv', data, layout);