pjt222
commented
2 years ago Hi @emilioxavier, I recently had a comparable issue with manualy defining node positions and followed a suggestion from https://stackoverflow.com/questions/5364264/how-to-control-the-igraph-plot-layout-with-fixed-positions
The following adaption worked for me.
library(igraph)
library(ggplot2)
library(ggraph)
fixed_coord_example <- function() {
nodes <- c("a", "b", "c", "d")
x <- c(0, .6, 1, 1)
y <- c(0, 0, 1, -1)
from <- c("a", "b", "b")
to <- c("b", "c", "d")
NodeList <- data.frame(nodes, x, y)
EdgeList <- data.frame(from, to)
a <- graph_from_data_frame(vertices = NodeList, d = EdgeList, directed = TRUE)
# plot(a)
ggraph(a, layout = "manual", x = x, y = y) +
geom_edge_fan(strength = 1, alpha = .5) +
geom_node_point(alpha = .5) +
geom_node_label(aes(label = nodes)) +
xlim(c(0, 1)) +
ylim(c(-1, 1))
}
fixed_coord_example()
Created on 2022-06-27 by the reprex package (v2.0.1)
Every node has an x and y position. Depending on your workflow, you could define them before creating a graph object (as in the example above) or afterwards. To change node and/or edge attributes of a graph object you should be aware of the activate function:
https://tidygraph.data-imaginist.com/reference/activate.html
Best regards Philipp
emilioxavier
Hi I am updating a collection of R functions that rely on graph and Rgraphviz (both from Bioconductor) along with gridGraphviz. I want to use the ggraph package to provide a better user experience and more options while reducing the reliance on multiple packages.
The goal is to make a graph similar to this one:
Unfortunately, I cannot figure out how to correctly align the nodes. Specifically, how do I assign a specific location within the plot area to a specific node?
Is defining the position of nodes possible with ggraph? Any help would be greatly appreciated. Even if, unfortunately, it is not possible.
Thank you Emilio