pygmt.Figure.vlines

Figure.vlines(x, ymin=None, ymax=None, pen=None, label=None, no_clip=False, perspective=None)

Plot one or multiple vertical line(s).

This method is a high-level wrapper around pygmt.Figure.plot that focuses on plotting vertical lines at X-coordinates specified by the x parameter. The x parameter can be a single value (for a single vertical line) or a sequence of values (for multiple vertical lines).

By default, the Y-coordinates of the start and end points of the lines are set to be the Y-limits of the current plot, but this can be overridden by specifying the ymin and ymax parameters. ymin and ymax can be either a single value or a sequence of values. If a single value is provided, it is applied to all lines. If a sequence is provided, the length of ymin and ymax must match the length of x.

The term “vertical” lines can be interpreted differently in different coordinate systems:

  • Cartesian coordinate system: lines are plotted as straight lines.

  • Polar projection: lines are plotted as straight lines along radius.

  • Geographic projection: lines are plotted as meridians along constant longitude.

Parameters:

  • x (float | Sequence[float]) – X-coordinates to plot the lines. It can be a single value (for a single line) or a sequence of values (for multiple lines).

  • ymin/ymax – Y-coordinates of the start/end point(s) of the line(s). If None, defaults to the Y-limits of the current plot. ymin and ymax can either be a single value or a sequence of values. If a single value is provided, it is applied to all lines. If a sequence is provided, the length of ymin and ymax must match the length of x.

  • pen (str | None, default: None) – Pen attributes for the line(s), in the format of width,color,style.

  • label (str | None, default: None) – Label for the line(s), to be displayed in the legend.

  • no_clip (bool, default: False) – If True, do not clip lines outside the plot region. Only makes sense in the Cartesian coordinate system.

  • perspective (str | bool | None, default: None) – Select perspective view and set the azimuth and elevation angle of the viewpoint. Refer to pygmt.Figure.plot for details.

Examples

>>> import pygmt
>>> fig = pygmt.Figure()
>>> fig.basemap(region=[0, 10, 0, 10], projection="X10c/10c", frame=True)
>>> fig.vlines(x=1, pen="1p,black", label="Line at x=1")
>>> fig.vlines(x=2, ymin=2, ymax=8, pen="1p,red,-", label="Line at x=2")
>>> fig.vlines(x=[3, 4], ymin=3, ymax=7, pen="1p,black,.", label="Lines at x=3,4")
>>> fig.vlines(x=[5, 6], ymin=4, ymax=9, pen="1p,red", label="Lines at x=5,6")
>>> fig.vlines(
...     x=[7, 8], ymin=[0, 1], ymax=[7, 8], pen="1p,blue", label="Lines at x=7,8"
... )
>>> fig.legend()
>>> fig.show()