Error in check.length(gparname) : 'gpar' element 'lwd' must not be length 0

[Dan Li]

Hello:

I tried the following code in Rstudio:

library(igraph)
library(ggraph)

set.seed(1)

adj <- matrix(rbinom(900, 1, 0.02) * runif(900, -1, 1), 30,
              dimnames = list(paste('node', 1:30), 
                              paste('node', 1:30)))

graph <- graph.adjacency(adj, weighted = TRUE)


ggraph(graph, layout = 'linear', circular = TRUE) + 
  geom_edge_arc(aes(color = weight, size = abs(weight))) + 
  geom_node_text(aes(label = name, angle = node_angle(x, y)), hjust = -0.5) +
  geom_node_point(shape = 21, size = 4, aes(fill = name)) +
  theme_graph() +
  scale_edge_color_gradientn(colours = c('red4', 'gold', 'green4')) +
  coord_fixed(xlim = c(-1.4, 1.4), ylim = c(-1.4, 1.4)) +
  guides(fill = guide_none())

but there is an error:

Error in check.length(gparname) : 
  'gpar' element 'lwd' must not be length 0

can you please let me know what is the problem? Thanks

[David Schoch]

There was a recent update of ggplot2, which underlies ggraph. For me, your code runs, but there is still a warning that probably shouldn't be there

library(igraph)
library(ggraph)

packageVersion("igraph")
#> [1] '1.3.5'
packageVersion("ggraph")
#> [1] '2.1.0'
packageVersion("ggplot2")
#> [1] '3.4.0'

set.seed(1)

adj <- matrix(rbinom(900, 1, 0.02) * runif(900, -1, 1), 30,
              dimnames = list(paste('node', 1:30), 
                              paste('node', 1:30)))

graph <- graph.adjacency(adj, weighted = TRUE)


ggraph(graph, layout = 'linear', circular = TRUE) + 
  geom_edge_arc(aes(color = weight, edge_linewidth = abs(weight))) + 
  geom_node_text(aes(label = name, angle = node_angle(x, y)), hjust = -0.5) +
  geom_node_point(shape = 21, size = 4, aes(fill = name)) +
  theme_graph() +
  scale_edge_color_gradientn(colours = c('red4', 'gold', 'green4')) +
  coord_fixed(xlim = c(-1.4, 1.4), ylim = c(-1.4, 1.4)) +
  guides(fill = guide_none())
#> Warning: Using the `size` aesthetic in this geom was deprecated in ggplot2 3.4.0.
#> ℹ Please use `linewidth` in the `default_aes` field and elsewhere instead.

^{Created on 2023-02-07 with reprex v2.0.2}

[Dan Li]

@schochastics Thanks I updated ggraph now it works.

packageVersion("igraph")
#> [1] '1.3.5'
packageVersion("ggraph")
#> [1] '2.1.0'
packageVersion("ggplot2")
#> [1] '3.4.0'