# Is it possible to achieve this type of design? **URL:** \ **Category:** Help\ **Created:** [July 8, 2021, 9:21pm UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738 "2021-07-08T21:21:21Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![solub](https://avatars.discourse-cdn.com/v4/letter/s/ad7895/32.png) [@solub](https://forum.graphviz.org/u/solub)\ **Post date:** [July 8, 2021, 9:21pm UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/1 "2021-07-08T21:21:21Z")
Hi again, I am trying to design a very specific type of graph with certain colors and shapes but I am unable to tell if this is achievable with Graphviz. My goal is to draw a directed graph where each node: - is composed of 3 smaller boxes aligned horizontally (`striped` `rectangle` or `record`, `rounded`) - contains 3 `labels` accordingly - is filled with a gradient - **has a black square node located on top of the middle box** Example (_all black boxes have been placed manually_) : ![testModel](https://global.discourse-cdn.com/graphviz/original/1X/eb60ad1c7399d701e17f49333a048d7c2f10247f.jpeg) I have made it to the third requirement but I am struggling implementing the last one. How would you place square nodes (`rect`, `square`, `box`, etc) on top of the first set of nodes (colored rectangles) so as they perfectly fit the dimensions of the middle boxes they are covering ? Is that even possible with Graphviz ? Example code (Python): ```auto # Dictionary storing relations between nodes d = {0: set([1, 2, 3]), 1: set([4, 5, 6]), 2: set([7, 8, 9, 10]), 3: set([0]), 4: set([]), 5: set([]), 6: set([]), 7: set([]), 8: set([0]), 9: set([]), 10: set([])} # List of node labels (3 labels per node) P = [('S', 'M', 'S'), ('M', 'S', 'L'), ('M', 'S', 'S'), ('M', 'S', 'M'), ('S', 'L', 'L'), ('S', 'L', 'M'), ('S', 'L', 'X'), ('S', 'S', 'S'), ('S', 'S', 'M'), ('S', 'S', 'L'), ('S', 'S', 'X')] # Dictionary storing the colors corresponding to each label c = {'S':'olivedrab1', 'M':'mediumturquoise', 'L':'deepskyblue', 'X':'palevioletred1'} # Create a "directed graph" with general node and edge attributes G = Digraph(node_attr={'shape':'record', 'style':'rounded, filled', 'color':'white', 'height':'0.1', 'fontcolor':'white'}, edge_attr={'color':'grey', 'arrowhead':'vee'} ) G.attr('graph', bgcolor='transparent') # 1st pass: create all nodes (0 to 10) for k in d: l1, l2, l3 = P[k] # set specific attribute to each node (label & colors) G.attr('node', label='{} | {} | {}'.format(l1, ' ', l2), fillcolor='{}:{}'.format(c[l1], c[l2])) G.node(str(k)) # 2nd pass: create edges between nodes for k in d: l1, l2, l3 = P[k] for i in d[k]: if i in d: G.edge(str(k), str(i)) # Then, how to overlap black square nodes ? ``` ---
**Author:** ![steveroush](https://avatars.discourse-cdn.com/v4/letter/s/a9adbd/32.png) [@steveroush](https://forum.graphviz.org/u/steveroush)\ **Post date:** [July 9, 2021, 12:12am UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/2 "2021-07-09T00:12:29Z")
```auto digraph G { node [shape=plaintext] t [label=<
00 02 03
>]; } ``` Giving: ![doneWithHtml](https://global.discourse-cdn.com/graphviz/original/1X/f20297e6da047dc509b32b8c10dba974fe389545.png) ---
**Author:** ![solub](https://avatars.discourse-cdn.com/v4/letter/s/ad7895/32.png) [@solub](https://forum.graphviz.org/u/solub)\ **Post date:** [July 9, 2021, 10:12am UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/3 "2021-07-09T10:12:39Z")
Hi, thank you for the pointer ! The problem with this approach is that: - there is 1 gradient per cell instead of 1 filling all three at once - gradients are filling the inner cells, not the larger node. - the overall outline is not sharp/clear because of the overlapping of multiple cell borders (inner+outer) Illustration: ![example](https://global.discourse-cdn.com/graphviz/original/1X/d0241b381bb80fccdfa075a7e0d6f57bc33f42c8.png) _When removing the inner cells’ borders for a cleaner outline, it becomes apparent that the gradients are not filling the main node._ Instead, is there a way to place a `rect` on top of the middle cell of a `record` node, just like in my previous example picture ? ---
**Author:** ![steveroush](https://avatars.discourse-cdn.com/v4/letter/s/a9adbd/32.png) [@steveroush](https://forum.graphviz.org/u/steveroush)\ **Post date:** [July 10, 2021, 9:36pm UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/4 "2021-07-10T21:36:54Z")
Very fiddly, but seemingly what you want. - Start with dot to position the nodes - Output to dot output format (dot -Tdot) (see [DOT | Graphviz](https://graphviz.org/docs/outputs/canon/)) - Use post-processing to add center node (see script below), - Finally run through **neato -n** ([FAQ | Graphviz](https://graphviz.org/faq/#FaqDotWithNodeCoords)) Demo graph: ```auto digraph G { node [shape=Mrecord fontcolor="white"] triple [style=filled fillcolor="red:blue" label="AA|BB|CC"]; } ``` I used **gvpr** to add the center node overlay (see [https://graphviz.org/pdf/gvpr.1.pdf](https://graphviz.org/pdf/gvpr.1.pdf)), but seemingly **python** (or others) could be used My script: ```auto f=gradientOverlay.gv; T=dot; F=`basename $f .gv`; /usr/bin/dot -T$T $f | /usr/bin/gvpr -c 'BEGIN{int Z=0;node_t aNode}N{Z++;aNode=node($G,"__top_" + (string)Z);aNode.width=.05+(float)$.width/3.;aNode.height=$.height;aNode.pos=$.pos;aNode.shape="rect";aNode.style="filled";aNode.fillcolor="black";aNode.label=html($G,"4π
8");}' |/usr/bin/neato -n -Tpng >O.png ``` Giving: ![O](https://global.discourse-cdn.com/graphviz/original/1X/df30b7ba641b276ff2ee4c1857a16ad3349f9813.png) The post-processing creates new, overlay nodes, using the **pos** of the original node. It sets attributes of the new node as needed, setting width to ~original width/3 and height to ~original height. ---
**Author:** ![solub](https://avatars.discourse-cdn.com/v4/letter/s/ad7895/32.png) [@solub](https://forum.graphviz.org/u/solub)\ **Post date:** [July 12, 2021, 10:57am UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/5 "2021-07-12T10:57:13Z")
Thank you so much! I’ll see if I can implement this in Python. ---
**Author:** ![solub](https://avatars.discourse-cdn.com/v4/letter/s/ad7895/32.png) [@solub](https://forum.graphviz.org/u/solub)\ **Post date:** [July 12, 2021, 5:07pm UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/6 "2021-07-12T17:07:53Z")
I am having a difficult time finding a way to do the same with Python. Am I correct that [gv.3python](https://www.graphviz.org/pdf/gv.3python.pdf) is the right extension to load in this case ? If so, where can I find it ? If not, would you mind sharing a transcription of your example in Graphviz Python ? That would be very helpful. ---
**Author:** ![steveroush](https://avatars.discourse-cdn.com/v4/letter/s/a9adbd/32.png) [@steveroush](https://forum.graphviz.org/u/steveroush)\ **Post date:** [July 14, 2021, 9:17pm UTC](https://forum.graphviz.org/t/is-it-possible-to-achieve-this-type-of-design/738/7 "2021-07-14T21:17:41Z")
[Note: _I am not a Python coder and have never used the PyGraphviz interface. Take my suggestions with a ton of salt_] My best guess: - I don’t think you need to worry about [gv.3python](https://www.graphviz.org/pdf/gv.3python.pdf) 1. Add the labels for the “overlay” nodes to the existing nodes using a new, made-up attribute name. I suggest something like **centerLabel**. It is completely legal to add new attribute name/value pairs to Graphviz files. Graphviz produces no error messages, but just passes them downstream. [after the code presented above] 2. G.layout to add positions to the graph 3. iterate through all the nodes. For each node with a **centerLabel** attribute (see above): 3.1. use **node** command to create the overlay node (using a new, unique node name) 3.2 set the overlay node **pos** equal to the old node **pos** 3.3 set the overlay node **shape** to “rect” 3.4 set the overlay node **style** to “filled” 3.5 set the overlay node **fillcolor** to “black” 3.6 set the overlay node **height** to ~ old node height - .02 3.7 set the overlay node **width** to ~ .05 + (old node width/3) 3.8 set the overlay node label to the old node **centerLabel** value 4. G.layout (again) but using the **neato** engine and **-n** arg 5. G.draw - I assume this produces the output This is “best guess”. I hope it helps in some way.