PyNGL Home > Functions > Graphics routines


Draws a polyline on the viewport.


Ngl.polyline_ndc(wks, x, y, res=None)



The identifier returned from calling Ngl.open_wks.

x, y

One-dimensional (masked) NumPy arrays or Python lists containing the x, y NDC coordinates of the polyline.


An (optional) instance of the Resources class having GraphicStyle resources as attributes.

Return value



This procedure draws a polyline on the viewport of the requested workstation. x and y are 1-dimensional arrays (these can be Python lists or tuples, or NumPy arrays) defining the coordinates of the polyline in NDC space, and resources can optionally contain an unlimited number of GraphicStyle attributes that are resource names and their values.

The frame is not advanced when you call this procedure, so you need to call Ngl.frame yourself if you want to advance the frame.

As of version 1.3.0, there is automatic handling of missing data if one or both of the input arrays are masked arrays. Missing data will not be plotted.

See Also

Ngl.polymarker_ndc, Ngl.polygon_ndc, Ngl.add_polyline, Ngl.polyline, Ngl.draw_ndc_grid


See example and its output.