d3dendro_options(..., copy = FALSE)"reset" is given, options
are restored to factory settings.node_fill (char,"#fff") Node color (fill)
node_stroke (char;"steelblue") Node color (circumference)
node_stroke_width (char;"1.5px") Width of node circumference
node_radius (num;4.5) Size of node (pixels)
node_font (char;"14px sans-serif") Font used to print labels. Size and type spec
link_fill (char;"none") link fill color (you probably do not want to set this)
link_stroke (char;"#ccc") link line color (that's the one you want)
link_stroke_width (char;"1.5px") link line width (pixels)
axis_stroke (char;"black") Color of axis line
axis_width (char; "2px") Width of axis line
axis_ntick (num; 5) Approximate nr of tick marks
axis_ticklength_in (num;5) Length of tickmarks into the graph (pixels)
axis_ticklength_out (num;5) Length of tickmarks out of the graph (pixels)
axis_tickmark_offset (num;8) Distance between axis and tick labels (pixels)
}