chore: handle new values of loops argument of degree() and max_degree()

R/aaa-auto.R

@@ -59,6 +59,20 @@ vcount_impl <- function(graph) {
   res
 }
 
+degree_impl <- function(graph, vids=V(graph), mode=c("all", "out", "in", "total"), loops=c("twice", "none", "once")) {
+  # Argument checks
+  ensure_igraph(graph)
+  vids <- as_igraph_vs(graph, vids)
+  mode <- switch(igraph.match.arg(mode), "out"=1L, "in"=2L, "all"=3L, "total"=3L)
+  loops <- switch(igraph.match.arg(loops), "none"=0L, "twice"=1L, "once"=2L)
+
+  on.exit( .Call(R_igraph_finalizer) )
+  # Function call
+  res <- .Call(R_igraph_degree, graph, vids-1, mode, loops)
+
+  res
+}
+
 get_all_eids_between_impl <- function(graph, from, to, directed=TRUE) {
   # Argument checks
   ensure_igraph(graph)

R/structural-properties.R

@@ -865,7 +865,11 @@ mean_distance <- average_path_length_impl
 #' @param mode Character string, \dQuote{out} for out-degree, \dQuote{in} for
 #'   in-degree or \dQuote{total} for the sum of the two. For undirected graphs
 #'   this argument is ignored. \dQuote{all} is a synonym of \dQuote{total}.
-#' @param loops Logical; whether the loop edges are also counted.
+#' @param loops Character string,
+#' `"none"` ignores loop edges;
+#' `"once"` counts each loop edge only once;
+#' `"twice"` (the default) counts each loop edge twice in undirected graphs
+#' and once in directed graphs.
 #' @param normalized Logical scalar, whether to normalize the degree.  If
 #'   `TRUE` then the result is divided by \eqn{n-1}, where \eqn{n} is the
 #'   number of vertices in the graph.
@@ -896,22 +900,33 @@ degree <- function(
   graph,
   v = V(graph),
   mode = c("all", "out", "in", "total"),
-  loops = TRUE,
+  loops = c("twice", "none", "once"),
   normalized = FALSE
 ) {
   ensure_igraph(graph)
-  v <- as_igraph_vs(graph, v)
   mode <- igraph.match.arg(mode)
-  mode <- switch(mode, "out" = 1, "in" = 2, "all" = 3, "total" = 3)
 
-  on.exit(.Call(R_igraph_finalizer))
-  res <- .Call(
-    R_igraph_degree,
+  if (is.logical(loops)) {
+    lifecycle::deprecate_soft(
+      "2.2.0",
+      "degree(loops = 'must be a character string')"
+    )
+    if (loops) {
+      loops <- "twice"
+    } else {
+      loops <- "none"
+    }
+  }
+
+  loops <- igraph.match.arg(loops)
+
+  res <- degree_impl(
     graph,
-    v - 1,
-    as.numeric(mode),
-    as.logical(loops)
+    vids = v,
+    mode = mode,
+    loops = loops
   )
+
   if (normalized) {
     res <- res / (vcount(graph) - 1)
   }
@@ -924,8 +939,36 @@ degree <- function(
 #' @rdname degree
 #' @export
 #' @cdocs igraph_maxdegree
-max_degree <- maxdegree_impl
+max_degree <- function(
+  graph,
+  ...,
+  v = V(graph),
+  mode = c("all", "out", "in", "total"),
+  loops = c("twice", "none", "once")
+) {
+  ensure_igraph(graph)
+  mode <- igraph.match.arg(mode)
+
+  if (is.logical(loops)) {
+    lifecycle::deprecate_soft(
+      "2.2.0",
+      "max_degree(loops = 'must be a character string')"
+    )
+    if (loops) {
+      loops <- "twice"
+    } else {
+      loops <- "none"
+    }
+  }
+  loops <- igraph.match.arg(loops)
 
+  maxdegree_impl(
+    graph,
+    v = v,
+    mode = mode,
+    loops = loops
+  )
+}
 #' @rdname degree
 #' @param cumulative Logical; whether the cumulative degree distribution is to
 #'   be calculated.

src/rinterface.c

@@ -188,6 +188,42 @@ SEXP R_igraph_vcount(SEXP graph) {
   return(r_result);
 }
 
+/*-------------------------------------------/
+/ igraph_degree                              /
+/-------------------------------------------*/
+SEXP R_igraph_degree(SEXP graph, SEXP vids, SEXP mode, SEXP loops) {
+                                        /* Declarations */
+  igraph_t c_graph;
+  igraph_vector_int_t c_res;
+  igraph_vs_t c_vids;
+  igraph_neimode_t c_mode;
+  igraph_loops_t c_loops;
+  SEXP res;
+
+  SEXP r_result;
+                                        /* Convert input */
+  R_SEXP_to_igraph(graph, &c_graph);
+  IGRAPH_R_CHECK(igraph_vector_int_init(&c_res, 0));
+  IGRAPH_FINALLY(igraph_vector_int_destroy, &c_res);
+  igraph_vector_int_t c_vids_data;
+  R_SEXP_to_igraph_vs(vids, &c_graph, &c_vids, &c_vids_data);
+  c_mode = (igraph_neimode_t) Rf_asInteger(mode);
+  c_loops = (igraph_loops_t) Rf_asInteger(loops);
+                                        /* Call igraph */
+  IGRAPH_R_CHECK(igraph_degree(&c_graph, &c_res, c_vids, c_mode, c_loops));
+
+                                        /* Convert output */
+  PROTECT(res=R_igraph_vector_int_to_SEXP(&c_res));
+  igraph_vector_int_destroy(&c_res);
+  IGRAPH_FINALLY_CLEAN(1);
+  igraph_vector_int_destroy(&c_vids_data);
+  igraph_vs_destroy(&c_vids);
+  r_result = res;
+
+  UNPROTECT(1);
+  return(r_result);
+}
+
 /*-------------------------------------------/
 / igraph_get_all_eids_between                /
 /-------------------------------------------*/

src/rinterface_extra.c

@@ -3983,30 +3983,6 @@ SEXP R_igraph_create(SEXP edges, SEXP pn, SEXP pdirected) {
   return result;
 }
 
-SEXP R_igraph_degree(SEXP graph, SEXP vids, SEXP pmode, SEXP ploops) {
-
-  igraph_t g;
-  igraph_vs_t vs;
-  igraph_vector_int_t vs_data;
-  igraph_vector_int_t res;
-  igraph_neimode_t mode = (igraph_neimode_t) Rf_asInteger(pmode);
-  igraph_bool_t loops=LOGICAL(ploops)[0];
-  SEXP result;
-
-  R_SEXP_to_igraph(graph, &g);
-  R_SEXP_to_igraph_vs(vids, &g, &vs, &vs_data);
-  igraph_vector_int_init(&res, 0);
-  IGRAPH_R_CHECK(igraph_degree(&g, &res, vs, mode, loops));
-
-  PROTECT(result=R_igraph_vector_int_to_SEXP(&res));
-  igraph_vector_int_destroy(&res);
-  igraph_vector_int_destroy(&vs_data);
-  igraph_vs_destroy(&vs);
-
-  UNPROTECT(1);
-  return result;
-}
-
 SEXP R_igraph_get_diameter(SEXP graph, SEXP pdirected, SEXP punconnected,
                            SEXP pweights) {
 

tests/testthat/test-structural-properties.R

@@ -65,9 +65,9 @@ test_that("max_degree() works", {
   g <- make_graph(c(1, 2, 2, 2, 2, 3), directed = TRUE)
   expect_equal(max_degree(g), 4)
   expect_equal(max_degree(g, mode = "out"), 2)
-  expect_equal(max_degree(g, loops = FALSE), 2)
-  expect_equal(max_degree(g, mode = "out", loops = FALSE), 1)
-  expect_equal(max_degree(g, mode = "in", loops = FALSE), 1)
+  expect_equal(max_degree(g, loops = "none"), 2)
+  expect_equal(max_degree(g, mode = "out", loops = "none"), 1)
+  expect_equal(max_degree(g, mode = "in", loops = "none"), 1)
   expect_equal(max_degree(g, v = c()), 0)
   expect_equal(max_degree(make_empty_graph()), 0)
 })

tools/stimulus/functions-R.yaml

@@ -34,9 +34,6 @@ igraph_neighbors:
 igraph_is_directed:
     IGNORE: RR, RC
 
-igraph_degree:
-    IGNORE: RR, RC
-
 igraph_edge:
     IGNORE: RR, RC, RInit