To add to this question, I would like to ultimately have a directed graph with variable edge colors and edge widths to represent the varying strengths of (directed) interactions between nodes in a network. I would also like to be able to control the coordinates where each vertex is plotted.
So far I have figured out that GraphPlot, allows specification of coordinates for vertices:
GraphPlot[{1->2,2->3,3->1},VertexCoordinateRules->{1->{0,0},2->{1,1},3->{0,2}}]
And Graph apparently allows full controls of the edge widths:
Graph[{1<->2,3 <-> 2,1<->3}, EdgeStyle -> {1<->2-> Directive[Thickness[0.01],Blue], 3 <-> 2 -> Directive[Thickness[0.005],Red], 1<-> 3 -> Directive[Thickness[0.02],Green]}]
But, the EdgeStyle Directives cannot be set for directed edges (as in the original question). Further, VertexCoordinateRules fors not work for Graph and EdgeStyle does not work for GraphPlot.
Is there a way to get everything that I want (control over vertex coordinates, and also control over individual edge widths)?