layout_with_drl: fixing nodes is not working

[vtraag]

Using the fixed argument does not work as intended. According to the C core documentation, the fixed argument is also not properly implemented, this should also be clarified in the R documentation.

[SimonMontfort]

I would like to have the first node set in a two mode network fixed while optimising the positions of the second node set. Is there any way of doing this? I have tried the following and more which I document in the igraph forum (see link below):

I noticed this error when running this example:

library(igraph)
## data
# sample graph and transform to two-mode network
g <- sample_pa(26, m=2)
tm <- get.adjacency(g, names=FALSE)
g <- graph_from_incidence_matrix(as.matrix(tm, time = max(events$time)))
# lon lat data for the first node-set of the two-mode network
lon <- c(8.156847,9.416345,9.368596,7.625363,7.702396,7.615194,7.073961,6.133073,9.06578,9.628154,7.156132,8.110061,6.780079,8.405384,8.24331,9.275258,8.591709,7.639228,8.756584,9.092979,8.808903,8.628586,6.657902,7.604754, 8.537324, 8.655167)
lat <-c(47.40973,47.31729,47.36624,46.82192,47.45168,47.56484,46.71842,46.22047,46.9811,46.65624,47.3507,47.06778,46.99553,46.92681,46.85235,47.23359,47.71354,47.30422,47.06192,47.56883,46.29559,46.77191,46.57009,46.20956,47.1573,47.41282)

# problem:
co <- layout_with_drl(g, use.seed = T, seed = cbind(lon, lat), fixed = T)

error:

Error in layout_with_drl(g, use.seed = T, seed = cbind(lon, lat), fixed = T) : 
  At DensityGrid.cpp:228 : Exceeded density grid in DrL, Internal DrL error

I would like to plot:

plot(g, layout=co, vertex.size=30, edge.arrow.size=0.2,
 vertex.label="", rescale=FALSE,
 xlim=range(co[,1]), ylim=range(co[,2]), vertex.label.dist=0,
 vertex.label.color="red", vertex.color = ifelse(V(g)$type == F, "red", "blue"))

link to igraph forum on the question: https://igraph.discourse.group/t/fix-position-of-nodes-with-layout-with-fr/290/13

[szhorvat]

fixed argument is removed in C core now, should be removed in R too (at least deprecated in 1.3)