This repo describes some useful patterns and tips in GraphVIZ for creating graphical dumps.
Graphviz is open source graph visualization software. It can be used for creating graphs from text file with special description. See more details on https://graphviz.org.
First steps and basic ideas can be found here: http://lib.custis.ru/Graphviz.
Most of the attributes are described very briefly or not mentioned because they are easy to find in official documentation. But some patterns are not explicitly described on official site, nor on side sources. That's why that reference was created.
First of all, quality of .png can be very poor. Use dpi attribute (Dots Per Inch) or .svg format (vector graphics) instead of .png.
Examples:
dpi = 100:
dpi = 20:
Example of code:
digraph G
{
graph [dpi = 20];
example_node1[label = "Hello, World!"];
example_node2[label = "Yet Another 'Hello, World!'"];
example_node1 -> example_node2 [color = "red"]
}
Same rank of nodes means that nodes are on the same line.
In GraphVIZ system of ranks is a stable way to layout nodes in one line.
rank --- attribute to set rank of node(s)
(Valid values: same (set nodes on the same rank), min (set nodes on the minimal rank), max (set nodes on the maximal rank)).
ranksep --- attribute to set distance between ranks (inches)
Example of code:
digraph G
{
graph [dpi = 100];
{rank = min;
above_other_nodes[label = "I'm high"];
}
{rank = same;
example_node1[label = "Hello, World!"];
example_node2[label = "Yet Another 'Hello, World!'"];
example_node3[label = "And Another 'Hello, World!'?!"];
example_node4[label = "Not 'Hello, World!'"];
}
{rank = max;
below_other_nodes[label = "I'm low, u know"];
}
example_node2 -> below_other_nodes [color = "green"];
example_node1 -> example_node2 -> example_node4 [color = "red"];
example_node1 -> example_node3 [color = "red"];
example_node2 -> example_node3 [color = "red"];
example_node2 -> above_other_nodes [color = "blue"];
}
Adding ranksep = 1.5:
digraph G
{
graph [dpi = 100];
ranksep = 1.5;
{rank = min;
above_other_nodes[label = "I'm high"];
}
{rank = same;
example_node1[label = "Hello, World!"];
example_node2[label = "Yet Another 'Hello, World!'"];
example_node3[label = "And Another 'Hello, World!'?!"];
example_node4[label = "Not 'Hello, World!'"];
}
{rank = max;
below_other_nodes[label = "I'm low, u know"];
}
example_node2 -> below_other_nodes [color = "green"];
example_node1 -> example_node2 -> example_node4 [color = "red"];
example_node1 -> example_node3 [color = "red"];
example_node2 -> example_node3 [color = "red"];
example_node2 -> above_other_nodes [color = "blue"];
}
The standard style of edges in GraphVIZ is very hard to control, but you can use splines attribute to change it. Tips given below are working nice with splines = ortho.
Default splines (without splines attribute)
splines = ortho:
Example of code:
digraph G
{
graph [dpi = 100];
splines = ortho
{rank = same;
example_node1[label = "Hello, World!"];
example_node2[label = "Yet Another 'Hello, World!'"];
example_node3[label = "And Another 'Hello, World!'?!"];
example_node4[label = "Not 'Hello, World!'"];
}
example_node1 -> example_node2 -> example_node4 [color = "red"];
example_node1 -> example_node3 [color = "red"];
example_node2 -> example_node3 [color = "red"];
}
minlen --- minimal length of edge (inches)
penwidth --- width of edge (pixels)
weight --- edge priority (attribute adds 'weight' to arrow, so GraphVIZ will try to make it as short as possible)
dir --- edge direction
Note that if you want to set two same attributes you should write both of them in "" (Example: style = "rounded, filled")
shape --- shape of node
style --- style of node (recommended value: rounded)
height, width --- maximal height and width of node in inches (use with
fixedsize = true to set fixed size of node)
penwidth --- width of node border
Example of code:
digraph G
{
graph [dpi = 100];
splines = ortho
bgcolor = "#2F353B"
edge[minlen = 3, penwidth = 3; color = "green"];
node[shape = "rectangle", style = "rounded, filled",
height = 3, width = 2.3, fixedsize = true,
fillcolor = "#00b899",
fontsize = 30,
penwidth = 5, color = "yellow"
]
{rank = same;
example_node1[label = "HW!"];
example_node2[label = "YAHW"];
example_node3[label = "AAHW?!"];
example_node4[label = "NHW"];
}
example_node1 -> example_node2 -> example_node4 [color = "red"];
example_node1 -> example_node3 [color = "red"];
example_node2 -> example_node3 [color = "red"];
}
It's very powerful architechture tool to create nice graphs. Can be used for edges and nodes. Examples of usage below.
To create ordered layout you can use edge's attribute weight and style = invis to create 'heavy' invisible edges. They bind nodes in needed order.
Example of code:
digraph G
{
graph [dpi = 100];
splines = ortho
edge[minlen = 3, penwidth = 3];
node[shape = rectangle, style = rounded, fixedsize = true,
height = 3, width = 2, fontsize = 30];
{rank = same;
node1[label = "1"];
node2[label = "2"];
node3[label = "3"];
node4[label = "4"];
node5[label = "5"];
node6[label = "6"];
node7[label = "7"];
}
node1 -> node7 [color = "green"];
node3 -> node1 [color = "green"];
node2 -> node6 [color = "green"];
node3 -> node6 [color = "green"];
node4 -> node2 [color = "green"];
}
Add 'heavy' arrows:
...
node1 -> node2 -> node3 -> node4 [weight = 5];
node4 -> node5 [weight = 5];
node5 -> node6 [weight = 5];
node6 -> node7 [weight = 5];
...
Add style = invis
...
node1 -> node2 -> node3 -> node4 [weight = 5, style = invis];
node4 -> node5 [weight = 5, style = invis];
node5 -> node6 [weight = 5, style = invis];
node6 -> node7 [weight = 5, style = invis];
...
We can use graph's attribute rankdir to set horizontal layout, but this layout isn't stable when you create edges.
digraph G
{
graph [dpi = 100];
edge[minlen = 3, penwidth = 3];
node[shape = rectangle, style = rounded, fixedsize = true,
height = 3, width = 2, fontsize = 30];
node1[label = "1"];
node2[label = "2"];
node3[label = "3"];
node1 -> node2 -> node3;
}
Default layout:
With rankdir = LR;:
Add node1 -> node3:
but you can use weight attribute (see Ordered layout) to fix nodes positions.
Another way is to use rank = same for nodes (see Ranks), which explicitly says that nodes should have the same rank on the picture. This variant is stable, so recommended.
rank = same is broken for node's attribute shape = record, which is very suitable for dump information. The problem appears if you try to create edges between adjacent nodes. There are two solutions:
- Not to use
record's as buggy shape. - Use
splines = orthowith records.
There is no way to set distance explicitly. So we have to use a trick.
We create two nodes (let's call them base nodes) with style = invis on rank = min and rank = max, then create our nodes on rank = same and connect our first node to each of base nodes. We set graph attribute ranksep = 1.5. That way we explicitly create space above and below our nodes and GraphVIZ won't squeeze picture vertically.
Without a trick:
With a visible trick:
With an invisible trick:
Example of code (see and understand Ranks to create invisible trick):
digraph G
{
graph [dpi = 100];
ranksep = 1.5;
splines = ortho
edge[minlen = 3, penwidth = 3];
node[shape = record, style = rounded,
fixedsize = true, height = 1, width = 2,
fontsize = 30];
{rank = min;
above_node[label = "I'm disappearing", width = 3];
}
{rank = same;
node1[label = "1"];
node2[label = "2"];
node3[label = "3"];
node4[label = "4"];
node5[label = "5"];
node6[label = "6"];
}
{rank = max;
below_node[label = "Don't look at me", width = 3];
}
above_node -> node1;
below_node -> node1;
node1 -> node2 -> node3 [weight = 5; style = invis];
node3 -> node4 -> node5 [weight = 5; style = invis];
node5 -> node6 [weight = 5, style = invis];
node1 -> node3;
node5 -> node2;
node1 -> node6;
node1 -> node4;
node3 -> node5;
}