Fix random graph generation.

DESCRIPTION

 Package: rsAnalysis
 Title: High-Level Tools for rsfMRI analysis
-Version: 0.4
+Version: 0.4.1
 Authors@R: 
     person(given = "Christian",
            family = "Hohenfeld",

R/make_random_graphs.R

@@ -6,28 +6,24 @@
 #' @param calc_mean_dist (logical) If TRUE calculates mean_distance for all
 #' graphs.
 #'
-#' If all reference graphs are of the same size, the random graphs will
-#' have a size ranging between size / 4 and size / 3.
-#'
 #' @return A list of tbl_graph objects of length `n`.
 #' @export
 make_random_graphs <- function(reference_graphs, n, calc_mean_dist = FALSE) {
-    sizes <- vapply(reference_graphs, igraph::gsize,
+    degree <- vapply(reference_graphs, function(x) mean(igraph::degree(x)),
                      numeric(1), USE.NAMES = FALSE)
+    degree <- round(mean(degree), 0)
     order <- vapply(reference_graphs, igraph::gorder,
                     numeric(1), USE.NAMES = FALSE)
     order <- round(mean(order), 0)
-
-    min_max_equal <- min(sizes) == max(sizes)
+    # use https://igraph.org/r/doc/sample_k_regular.html
 
     random_list <- lapply(1:n, function(x)
-        tidygraph::play_erdos_renyi(
-            n = order,
-            m = ifelse(min_max_equal,
-                       sample((sizes[1] / 4):(sizes[1] / 3), 1),
-                       sample(min(sizes):max(sizes), 1)),
-            directed = FALSE
-        )
+        igraph::sample_k_regular(
+            no.of.nodes = order,
+            k = degree,
+            directed = FALSE,
+            multiple = FALSE
+        ) %>% tidygraph::as_tbl_graph()
     )
 
     if (calc_mean_dist) {

man/make_random_graphs.Rd

@@ -13,10 +13,7 @@ determining the size of the random graphs.}
 \item{n}{(int) The amount of graphs to generate.}
 
 \item{calc_mean_dist}{(logical) If TRUE calculates mean_distance for all
-graphs.
-
-If all reference graphs are of the same size, the random graphs will
-have a size ranging between size / 4 and size / 3.}
+graphs.}
 }
 \value{
 A list of tbl_graph objects of length `n`.

tests/testthat/test-make_random_graphs.R

 describe("make_random_graphs", {
     data("graph_list")
-    gl <- lapply(graph_list, function(x) binarise_graph_fixed(x, weight, 0.05))
+    gl <- lapply(graph_list, function(x) {
+        x %>%
+            remove_loops() %>%
+            remove_duplicate_edges() %>%
+            binarise_graph_prop(weight, 0.5)
+    })
 
     it("creates a list of graphs with length n", {
         rand <- make_random_graphs(gl, 10)
         expect_length(rand, 10)
     })
 
-    it("creates graphs of varying size, even if input has all equal sizes", {
-        rand <- make_random_graphs(graph_list, 10)
+    it("creates graphs of equal size", {
+        rand <- make_random_graphs(gl, 10)
         sizes <- sapply(rand, igraph::gsize)
-        expect_gt(length(unique(sizes)), 1)
+        expect_equal(length(unique(sizes)), 1)
     })
 
     it("calculates mean distance if requested", {