LayeredGraphPlot¶

Draws a graph in layers: every vertex sits one layer further from a root than the parent that first reached it.

$ wo 'Head[LayeredGraphPlot[{1 -> 2, 2 -> 3, 2 -> 4}]]'
Graphics

The second argument says which edge of the plot the roots go on, and the layers grow away from it — Left draws the graph left to right:

$ wo 'Head[LayeredGraphPlot[{1 -> 2, 2 -> 3, 2 -> 4}, Left]]'
Graphics

DirectedEdges -> False draws the edges as plain lines instead of arrows, and ImageSize sizes the picture:

$ wo 'Head[LayeredGraphPlot[{1 -> 2, 2 -> 3}, Left, DirectedEdges -> False, ImageSize -> {200, 50}]]'
Graphics