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Line Markers

You can add lines to line or bar charts to highlight trends.

To add multiple lines (or combine this with any other chm markers), separate the chm parameter sets using a pipe ( | ) delimiter. You cannot make a dashed line marker with this parameter.


  • D Indicates that this is a line marker.
  • <color> The color of the line, in RRGGBB hexadecimal format.
  • <series_index> The index of the data series used to draw the line. The data series index is 0 for the first data series, 1 for the second data series, and so on.
  • <which_points> Which points in a series to use to draw the line. Use one of the following values:
    • 0 - Use all the points in the series.
    • start:end - Use a specific range of points in the series, from the start to end, inclusive (zero-based index). You can also use floating point values to specify intermediate points, or leave start or end blank to indicate the first or last data point, respectively. start and end can be negative, as a reverse index from the last value. If both start and end are negative, be sure to write them in increasing value (for example, -6:-1).
  • <size> The width of the line in pixels.


This is an example of drawing a marker line on a bar chart. The z-order is set to 1, so the line is drawn on top of the bars. This example uses the same data for both the bars and the data line.

compound chart


This is the same bar chart, but with an additional data series just for the line. This is an example of a compound chart. Compound charts are drawn by adding additional data series to the chd parameter, plus a value to chd telling the chart to "ignore" the additional data series.

See Compound Charts for more information.