I'm trying to make basic polygons with graphviz. I have something like this:
graph {
node [shape=circle]
A [pos="0,1!"]
B [pos="0,0!"]
C [pos="1,0!"]
D [pos="1,1!"]
A -- B
B -- C
C -- D
D -- A
}
which displays the following
I'd like the circles to disappear and look more like this:
I tried switching to shape=point, but the labels disappear. Any suggestions?
When using shape=point, adding a xlabel to each node will display a label outside of the node shape:
A [pos="0,1!", xlabel="A"]
The documentation states that the label will be placed outside the node shape, but near the node itself. However, those labels are placed last and can sometimes be omitted (forcelabels to the rescue).
The position or an offset can not be defined.
Related
I would like to create a spline curve between the blue point and the green point with the red point as a control point.
Graphviz documentation says :
splines attribute, of type bool or string, is valid on Graphs
splineType with the pattern : spline ( ';' spline )* is a valid type for pos attribute
pos attribute is valid on Edges and Nodes
I Tried this graph
graph G{
layout ="neato" outputorder="edgesfirst" splines="true"
a[shape="point" pos="0,0!" color="blue"]
b[shape="point" pos="1,0!" color="green"]
c[shape="point" pos=" 0.5,0.5!" color="red"]
a -- b [pos="e,1,0 s,0,0 0.5,0.5!"]
}
then on Windows 10 PowerShell :
neato.exe -Tsvg .\spline.dot > .\spline.svg
with
neato - graphviz version 2.49.3 (20211023.0002)
result
What is the proper way of achieving this?
Thanks.
Close, but ...
! notation seems to only apply to nodes (not edges) (poorly documented, but see: https://graphviz.org/docs/attr-types/point/ and https://graphviz.org/docs/attrs/pin/)
by default, pos value units are points (inch/72). Your values are ~ too small
neato -n2 will use node & edge values you provide (https://graphviz.org/faq/#FaqDotWithCoords)
all edges (not just curves) are defined as cubic B-splines and are defined by 1 + n*3 points (n is integer >=1) (https://graphviz.org/docs/attr-types/splineType/) (i.e. 4 or 7 or 11 or ...)
So:
graph G{
// default units for pos values are in points (72/inch)
// multiplied by 100 out of laziness
// ! only applies to nodes, not edges
layout ="neato"
outputorder="edgesfirst" // why???
splines="true"
a[shape="point" pos="0,0!" color="blue"]
b[shape="point" pos="100,0!" color="green"]
c[shape="point" pos="50,50!" color="red"]
// "s" arrowhead must preceed "e" arrowhead, so swaped them
// BUT, "--" says non-directed graph, NO arrowheads, so they are deleted
// also need 4, 7, 11, ... points NOT including arrowhead points
// so added points (just guesses)
a -- b [pos="0,0 30,66 70,66 100,0"]
}
Gives:
Whew
How to use Graphviz to align nodes circular in clusters with additional text? Optionally with identical node positions (always 8 nodes per cluster)?
I tried circo, however, faced some shortcomings:
No clustering
No comments
Problems with margins for larger labels (10+ char)
Alignment varies with label size
This (Graphviz Online), nothing spectacular, was the closest I could get. Any hints to other layouts (or even tools) appreciated.
graph {
layout = circo;
node [shape = circle,
fontname = Helvetica,
margin = 0]
edge [style=invis]
subgraph 1 {
a1 -- b1 -- c1 -- d1 -- e1 -- f1 -- g1 -- h1 -- a1
}
subgraph 2 {
a -- b -- c -- d -- e -- f -- g -- h -- a
}
}
Not exactly the answer as I was asking for (Graphviz), but I found a much nicer solution with MATLAB. It was about plotting a seating plan for an event.
What I did broken down:
imread() image of the floor plan
Roughly determined pixel spacing, used as x & y vector for image() so that tables are in scale with the room.
Manually defined centers for the clusters (here tables) with the help of ginput() (or imellipse())
Plotted circles with plot() and added text with text()
I have a simple vertical graph that looks nice and symmetrical without any labels using the following code:
digraph test_alignment
{
{rank=same; a -> b;}
a -> c;
b -> c;
c -> d;
d -> e;
d -> f;
{rank=same; e -> f;}
}
I'd like to label the edge between A and B as well as the one between E and F, using the same string for each label. I'm expecting the same output, except with longer A->B and E->F edges bearing the same label.
Unfortunately, as soon as I add a label to one of these edges, the general layout looks slightly askew (the result is similar if I add a label to the E->F edge):
digraph test_alignment
{
{rank=same; a -> b [label="Label"];}
a -> c;
b -> c;
c -> d;
d -> e;
d -> f;
{rank=same; e -> f;}
}
I'm very new to graphviz and, following many questions on Stack Overflow, I have been experimenting with different combinations of rank and constraint, I tried using clusters to see if it would keep the top and bottom part properly aligned independently, and tried using a mix of dot, ccomp, gvpack and neato that produced similar results.
It always seems to boil down to the fact adding a label to the edge between nodes with the same rank affects how these nodes are positioned in a way I don't yet understand.
Am I missing something trivial, or am I attempting something I shouldn't instead of letting dot do its thing?
I'm using dot - graphviz version 2.36.0 (20140111.2315) and the linked pictures were produced with dot only (though I obtained similar results when using :
dot test_alignment.dot -Tpng -O
You may try to use the xlabel attribute, together with forcelabels if necessary. From the description:
... For edges, the label will be placed near the center of the edge. This
can be useful in dot to avoid the occasional problem when the use of
edge labels distorts the layout. ...
See the line on the leftmost side of this image.
This isn't a perfect example because the lines don't end on a node, but imagine that there is a node on the bottom left corner of the image. Normally in graphviz if I have a graph like this:
digraph G {
a->c
b->c
}
Then I get two separate lines going into c. Is it possible to have these two lines join before they reach c?
Yes, it is possible to have two lines join before they reach c but, as far as I can see, it requires inserting an invisible node to do it. e.g.:
digraph G {
x [style=invis, height=0, label=""]
a->x [dir=none]
b->x [dir=none]
x->c
}
... which gives:
I was trying to write my own little algorithm for graph layout that only creates a node layout but does not define edge routes. When I use Graphviz to turn the resulting dot file into a graph, the edges are straight lines that cross the nodes and even overlap each other. Is there a way to use Graphviz to layout the edges as nicely as the dot algorithm does, but have the nodes in predetermined fixed positions?
You can see the effect for instance on the following graph:
digraph test {
"a" [pos="0.0,0.0"];
"b" [pos="50.0,50.0"];
"c" [pos="100.0,100.0"];
"a" -> "b";
"a" -> "c";
"b" -> "c";
}
When drawn with dot -Knop -Tpng -otest.png test.dotty the line between a and c crosses b. What I want is that all nodes keep their positions, but the line between a and c goes around b.
Just add:
splines=true;
to your graph - result is: