need help with social network empty graph

[nirmo]

hello , i have problome with my social network , idid get the network but icannot add legends to it please help
heres the instruction :
Each quake is characterized by a couple of integers which determine its position in space (latitude and longitude). Create an empty social network in which each quake is represented by a node (empty_graph() %>% plot.igraph()): • Node size depends on quake intensity (vertex.size = …) • Node color depends on quake depth (vertex.color = …) • Node position depends on latitude and longitude columns (layout = …) Adjust the different parameters to make your map readable (node size, color and latitude/longitude). Add a title and a legend explaining nodes’ color (legend())

my codes :
attach(quakes)
library(igraph)
eg=make_empty_graph(n=1000,directed = F)
plot.igraph(eg,layout=as.matrix(select(quakes,lat,long)),vertex.color=quakes$depth,vertex.size=quakes$mag*5, main="network of quakes")
legend("bottomleft", legend=levels(as.factor(V(eg) , col = coul , bty = "n", pch=20 , pt.cex = 3, cex = 1.5, text.col=coul , horiz = FALSE, inset = c(0.1, 0.1))
what am i doing wrong? without the legends i get the network but with it igot an error

[mara]

I'm not 100% sure without your data, but the igraph documentation on Drawing Graphs suggests you need to use one of its plotting functions (not base plot()):

The common bits of the three plotting functions plot.igraph , tkplot and rglplot are discussed in this manual page

Edit Actual answer in @Yarnabrina's response, below.

[Yarnabrina]

I think the choice of plotting function is not the reason of the problem.

The OP missed a , after the vertex.size argument. Also, the as.factor parts are not necessary.

The following works.

library(igraph)
#> 
#> Attaching package: 'igraph'
#> The following objects are masked from 'package:stats':
#> 
#>     decompose, spectrum
#> The following object is masked from 'package:base':
#> 
#>     union
eg <- make_empty_graph(n = 1000,
                       directed = FALSE) 
plot(x = eg,
     vertex.color = quakes$depth,
     vertex.size = quakes$mag, 
     vertex.frame.color = "gray",
     vertex.label.color = "black")

^{Created on 2019-03-12 by the reprex package (v0.2.1)}

[nirmo]

ty it did show me the empty graph but im not sure the nodes set by lat and long variables

[Yarnabrina]

I'm not sure I understand the reason for which the nodes will be set by lat and long of quakes dataset in an empty graph. Can you please explain what you want?

[nirmo]

yeha , my data "quakes" has 5 variable lat,long,depth,stations and mag .
lat- latitude of the earthquake
long - longtiude of the earthquke
depth- depth of the eqrthquke at km
stations- number of statinos who report the earthquake
and mag- the magntiude of the earthquke
i need to make an empty graph which the nodes are earthquke by their long and lat for example earthquker 1 has lat 5 and long 7
and i need each node to be coloer by his depth values and sized by his mag values

[Yarnabrina]

I'm not sure I understand you correctly. From what I understand, you're looking for just a scatterplot.

library(ggplot2)
ggplot(data = quakes) +
  geom_point(mapping = aes(x = lat,
                           y = long,
                           colour = depth,
                           size = mag))

^{Created on 2019-03-13 by the reprex package (v0.2.1)}

[nirmo]

i need to make an empty graph and the R program said error
the function :
attach(quakes)
library(dplyr)
library(igraph)
empty=make_empty_graph(quakes)
layouts=as.matrix(select(quakes,lat,long))
View(layouts)
plot(empty,vertex.color=quakes$depth,vertex.size=quakes$mag, main="network of quakes")
why is it not working ? and ps how do i add a graph key ?
ty

[Yarnabrina]

I'll suggest you go through the documentation of make_empty_graph. See the excerpt below:

Usage

make_empty_graph(n = 0, directed = TRUE) empty_graph(...)

Some more details from here.

#' A graph with no edges
#'
#' @aliases graph.empty
#' @concept Empty graph.
#' @param n Number of vertices.
#' @param directed Whether to create a directed graph.
#' @return An igraph graph.
#'
#' @family determimistic constructors
#' @export
#' @examples
#' make_empty_graph(n = 10)
#' make_empty_graph(n = 5, directed = FALSE)

make_empty_graph <- function(n=0, directed=TRUE) {
  # Argument checks
  n <- as.integer(n)
  directed <- as.logical(directed)
  
  on.exit( .Call(C_R_igraph_finalizer) )
  # Function call
  res <- .Call(C_R_igraph_empty, n, directed)
  
  res
}

You can only supply an integer to this function to the n argument. That's why you're getting an error.

What exactly do you want to plot? And, how does it differ from the scatterplot I provided before?

[nirmo]

this is actully no diffrent but at my home work assiment they asked for igraph specifcly