Problem on edge colour geom_edge_link colour and node colour geom_node_point

[DanielIAvila]

I am experiencing this exact same issue. In my graph I have specified a color under E(g)$color that I want to use, and it is not working. It is taking the default colors used in ggplot2.

I have tried both the combination and stand-alone version of what is described here and it is not working. I have tried it for the nodes, and it is not working either. The graph g has attributes V(g)$year, V(g)$type, V(g)$size, V(g)$color, E(g)$color .

I need to color the nodes and the edges according to the specified attributes.

ggraph(g, layout = layout_matrix) +
  geom_edge_link(aes(edge_colour=factor(E(g)$colour), colour=factor(E(g)$colour)), show.legend = FALSE) +
  geom_node_point(aes(size = size, colour = color), show.legend = FALSE)

Below my R session:

sessionInfo()

R version 4.3.3 (2024-02-29 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19042)

other attached packages:
 [1] lubridate_1.9.3    forcats_1.0.0      stringr_1.5.1      purrr_1.0.2       
 [5] readr_2.1.5        tidyr_1.3.1        tibble_3.2.1       tidyverse_2.0.0   
 [9] RColorBrewer_1.1-3 ggraph_2.2.1       ggplot2_3.5.0      igraph_2.0.3      
[13] jsonlite_1.8.8     readxl_1.4.3       dplyr_1.1.4        openalexR_1.3.1   

loaded via a namespace (and not attached):
 [1] tidyselect_1.2.1   viridisLite_0.4.2  farver_2.1.1       viridis_0.6.5     
 [5] fastmap_1.1.1      tweenr_2.0.3       timechange_0.3.0   lifecycle_1.0.4   
 [9] sf_1.0-16          magrittr_2.0.3     compiler_4.3.3     rlang_1.1.3       
[13] progress_1.2.3     tools_4.3.3        utf8_1.2.4         ggsignif_0.6.4    
[17] prettyunits_1.2.0  labeling_0.4.3     graphlayouts_1.1.1 bit_4.0.5         
[21] classInt_0.4-10    curl_5.2.1         abind_1.4-5        KernSmooth_2.23-22
[25] withr_3.0.0        grid_4.3.3         polyclip_1.10-6    fansi_1.0.6       
[29] ggpubr_0.6.0       e1071_1.7-14       colorspace_2.1-0   scales_1.3.0      
[33] MASS_7.3-60.0.1    cli_3.6.2          crayon_1.5.2       generics_0.1.3    
[37] rstudioapi_0.15.0  httr_1.4.7         tzdb_0.4.0         DBI_1.2.2         
[41] cachem_1.0.8       ggforce_0.4.2      proxy_0.4-27       parallel_4.3.3    
[45] cellranger_1.1.0   vctrs_0.6.5        carData_3.0-5      car_3.1-2         
[49] hms_1.1.3          bit64_4.0.5        rstatix_0.7.2      ggrepel_0.9.5     
[53] units_0.8-5        glue_1.7.0         stringi_1.8.3      gtable_0.3.4      
[57] munsell_0.5.0      pillar_1.9.0       R6_2.5.1           tidygraph_1.3.1   
[61] vroom_1.6.5        backports_1.4.1    memoise_2.0.1      broom_1.0.5       
[65] class_7.3-22       Rcpp_1.0.12        gridExtra_2.3      pkgconfig_2.0.3

[schochastics]

No need to turn the colours to a factor. You can use the I() function to use the colour that is explicitely saved as an attribute

library(ggraph)
library(igraph)

g <- make_graph("zachary")
E(g)$colour <- "red"
E(g)$colour[incident(g, 1)] <- "blue"
layout_matrix <- graphlayouts::layout_with_stress(g)
V(g)$size <- degree(g)
V(g)$color <- as.character(membership(cluster_louvain(g)))

#not working
ggraph(g, layout = layout_matrix) +
    geom_edge_link(aes(edge_colour = factor(E(g)$colour), colour = factor(E(g)$colour)), show.legend = FALSE) +
    geom_node_point(aes(size = size, colour = color), show.legend = FALSE)

#working
ggraph(g, layout = layout_matrix) +
    geom_edge_link(aes(edge_colour = I(E(g)$colour), colour = I(E(g)$colour)), show.legend = FALSE) +
    geom_node_point(aes(size = size, colour = color), show.legend = FALSE)

^{Created on 2024-05-30 with reprex v2.1.0}