Gnuplot 5.2.7

Lines

The lines style connects adjacent points with straight line segments. It may be used in either 2D or 3D plots. The basic form requires 1, 2, or 3 columns of input data. Additional input columns may be used to provide information such as variable line color (see rgbcolor variable).

2D form (no "using" spec)

1 column:   y       # implicit x from row number
2 columns:  x  y

3D form (no "using" spec)

1 column:   z       # implicit x from row, y from index
3 columns:  x  y  z

See also linetype, linewidth, and linestyle.