Displaying horizontal flowcharts in pydot - python

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", ...)

Related

How to draw different shapes with Python using Graphviz

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()

Can the plotly.io.write_html be used to also plot images?

Usually, we use the line to plot graphs and confusion matrices. However, the official documentation doesn't really specify which types of figures are supported.
Can I actually use it for image files?
(I tried using it but it doesn't run properly, I don't know whether it was because of it not supporting it)
Based on the documentation, it supports a fig meaning a plotly figure object.
Unless you create a plotly figure object containing your image, you won't be able to use plotly.io.write_html(fig, ...)

Embed LaTeX in Graphviz

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.

Plot vertex as image in Igraph

I'm wondering if it is possible to plot a vertex as image (loaded from a file or directly) in Igraph. Any ideas?
This is definitley possible in the R version of iGraph using the raster function, however a brief search did not reveal any implementation of this function in Python (it's not in the igraph documentation anyway).
If this is essential to your work, then I would consider switching to R, or possibly another tool such as Gephi. For Python, however, you might consider using something like pyvis. This package is small but powerful in terms of visualization. I've been playing around with it over the past few days and its very easy to display a graph with pictures as nodes, and it comes with the added benefit of providing interactive functioning. Take a look at the tutorial here, which will highlight what this package can provide.

Tool to create a python GUI for graph construction

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.

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