I am creating a graph using python and graphviz.
So my script goes like :
from graphviz import Digraph
dot = Digraph()
dot.node('Start')
dot.node('Calculate A')
dot.edge('Start', 'Calculate A')
and so on.
I need to write math text in some nodes, let's say, replace 'A' by an integral. How can that be done?
Thanks in advance,
M
Sorry, Graphviz does not support LaTeX.
In theory, you could use Unicode & Graphviz (pseudo) HTML to create what you want, but it would probably be quite challenging.
A (pretty) easy way to combine LaTex and Graphviz would be to create separate image files (svg, png, jpeg, ...) - one per node using your "usual" LaTeX processes and then "including" these files in your Graphviz program using the image attribute.
Related
I tried to draw structure graph with Python. Nodes are like this
.
Since I also need to use different shape of arrows. So I wanted to use Graphviz to implement this. Is there any method to draw like this?
Many people seem to use PyPl (https://pypi.org/project/graphviz/) to interface Python to Graphviz. Read all the installation instructions & remember to install the actual Graphviz system.
There are two ways to build node structures, I recommend HTML-like nodes (https://graphviz.org/doc/info/shapes.html#html) (a bit wordy, but fewer layout restrictions)
There are few options to interface Graphviz with python:
graphviz
pygraphviz
graphviz-python
pydot
You can use Records-based Nodes or HTML-based Nodes to get the intended result:
import graphviz
g = graphviz.Digraph('G')
g.node('n1', '{name|{a|b|c}}',
shape='record',
fillcolor='skyblue',
style='filled')
g.view()
Is there any official documentation for building graphes associated to skeletons of images in python in the SKNW package? I found this package that I've installed, however, since I'm new in python, it's not easy for me to handle the latter: https://github.com/yxdragon/sknw .
Thanks for using sknw:
just load your 2d/3d image, you can use skimage.morphology.skeletonize_3d(img) to get a 3d skeleton from volume data.
graph = sknw.build_sknw(skeļ¼ multi=False) to got the skeleton structure, which is a networkx object.
do your analysis
graph.node[id]['pts'] : Numpy(x, n), coordinates of nodes points
graph.node[id]['o']: Numpy(n), centried of the node
graph.edge(id1, id2)['pts']: Numpy(x, n), sequence of the edge point
graph.edge(id1, id2)['weight']: float, length of this edge
and you can do some graph analysis use networkx.
I think you would be intrested in my another project ImagePy, which you can do many image processing operation in a UI framework, just like imagej
I am using python module for pydot to make flowcharts. But the flowcharts are being generated in a vertical fashion. I want them to be generated in a horizontal way. Is there any way that this can be achieved?
You need to give your graph the rankdir=LR attribute, as shown in this Graphviz forum post.
I don't know pydot (but I have written a few programs that create graphs in the DOT language), so I don't know the exact syntax you need to use, and I'm having trouble locating docs for pydot, but it appears that you can just pass the attribute as a keyword in the Dot constructor, eg
dot_object = pydot.Dot(graph_name="main_graph", rankdir="LR", ...)
I need to create a GUI for graph construction ("graph" as an abstract representation of a set of objects, not a visual representation of data). The interface will provide a choice of ~5 vertex types and of ~5 edge types. Each vertex will have two data fields: a text label and a file name, which need to be easily editable.
I'm familiar with igraph and have a lot of code written in it. I will use igraph to manipulate the graphs created with this GUI.
Since this will be my first GUI, I'm completely ignorant of what tools are available. Can you please suggest a free library, knowing that eventually the program will need to work on Windows?
EDIT
it seems from the answers I get that I wasn't clear enough. I'm not looking for a way to visualize a graph, but rather for a way to visually create one. By visually, I mean not needing to manually create text files or writing code.
Take a look at xdot.py.
From the homepage
xdot.py is an interactive viewer for graphs written in Graphviz's
dot language.
It uses internally the graphviz's xdot output format as an
intermediate format, and PyGTK and Cairo for rendering.
xdot.py can be used either as a standalone application from
command line, or as a library embedded in your python application.
I like networkx,
from networkx import draw, Graph
from pylab import show
g = Graph()
g.add_edges_from([(1,2),(1,3),(2,4),(2,5)])
draw(g)
show()
which gives,
The only quirk is the requirement for matplotlib to get builtin plotting to work.
If you use python, I think PyQt is a good selection.
What you have to install is listed below:
install Python from here
install PyQt4 from here
But it takes many lines to write GUI application,
it is sometimes better to generate an image to display with image viewer.
I have taken an initial DOT file and modified the pos attributes of some nodes using pydot. Now I want to render an image file that shows the nodes in their new positions. The catch is, I don't want a layout program to mess with the positions! I just want to see the nodes exactly where the pos attribute indicates. I don't care about how the edges look.
I can produce a DOT file with my positions easily using pydot, but I can't figure out how to make an image file, either in pydot or on the command line with dot. Help would be really appreciated! Thanks!
dot.write_png('filename.png')? Or is there something I'm missing?
Also, the neato command-line program has a -n option for graph files that already have layout. The program description says it is for undirected graphs, but I tried it with a digraph and it produced the correct result.