15.4.2 Line Styles ------------------ Line styles are specified by the following properties: ‘linestyle’ May be one of "-" Solid line. [default] "--" Dashed line. ":" Dotted line. "-." A dash-dot line. "none" No line. Points will still be marked using the current Marker Style. ‘linewidth’ A number specifying the width of the line. The default is 1. A value of 2 is twice as wide as the default, etc.