Automatically Assign Color To Nodes In Graphviz

I'm using Python and Graphviz to draw some cluster graph consist of nodes. I want to assign different colors to each node, dependent on an attribute, e.g. its x-coordinate. Here's

Solution 1:

Oh I figured out a way to get what I want. Just for recording and for someone else may have a same problem(?) Can just rescale a color map and assign the corresponding index (of color) to the nodes.

def add_nodes(graph, nodes):
for n in nodes:
    if isinstance(n, tuple):
        graph.node(n[0], **n[1])
    else:
        graph.node(n)
return graph

A = [[517, 1, [409], 10, 6], 
     [534, 1, [584], 10, 12], 
     [614, 1, [247], 11, 5], 
     [679, 1, [228], 13, 7], 
     [778, 1, [13], 14, 14]]

nodesgv = []
Arange = [ a[0] for a in A]
norm = mpl.colors.Normalize(vmin = min(Arange), vmax = max(Arange))
cmap = cm.jet

for index, i in enumerate(A):
    x = i[0]
    m = cm.ScalarMappable(norm = norm, cmap = cmap)
    mm = m.to_rgba(x)
    M = colorsys.rgb_to_hsv(mm[0], mm[1], mm[2])
    nodesgv.append((str(i[0]),{'label': str((i[1])), 'color': "%f, %f, %f" % (M[0], M[1], M[2]), 'style': 'filled'}))

graph = functools.partial(gv.Graph, format='svg', engine='neato')
add_nodes(graph(), nodesgv).render(('img/test'))