Implemented an EgoStat for absdiffcat(), and added tests for it.

R/EgoStat.R

@@ -192,6 +192,7 @@ split_aaties_by_ego <- function(x, egor){
 #' * `nodematch`
 #' * `nodemix`
 #' * `absdiff`
+#' * `absdiffcat`
 #' * `degree`
 #' * `degrange`
 #' * `concurrent`
@@ -397,6 +398,36 @@ EgoStat.absdiff <- function(egor, attr, pow=1){
   h
 }
 
+EgoStat.absdiffcat <- function(egor, attr, base=NULL, levels=NULL){
+  if(!missing(base)) message("In term `absdiffcat' in package `ergm.ego': Argument \"base\" has been superseded by \"levels\" and it is recommended to use the latter.  Note that its interpretation may be different.")
+
+  egos <- as_tibble(egor$ego)
+  alters <- egor$alter
+
+  xe <- ergm.ego_get_vattr(attr, egos)
+  xa <- ergm.ego_get_vattr(attr, alters)
+
+  attrname <- attributes(xe)$name
+
+  ux <- unique(c(xe,xa))
+  u <- sort(unique(as.vector(abs(outer(ux,ux,"-")))),na.last=NA)
+  u <- u[u>0]
+  if(missing(levels) && any(NVL(base,0)!=0)) u <- u[-base]
+
+  levs <- ergm.ego_attr_levels(levels, u, egor)
+  nlevs <- length(levs)
+
+  if (nlevs==0)
+    stop("Argument to `absdiffcat' has too few distinct differences.")
+
+  xal <- split_alters_by_ego(xa, egor)
+
+  h <- .mapply_col(function(e,a) .extabulate(.matchNA(abs(e-a), levs, 0), nbins=nlevs)/2, xe, xal, SIMPLIFY=TRUE)
+  colnames(h) <- paste("absdiff",attrname,levs,sep=".")
+  attr(h, "order") <- 1
+  h
+}
+
 EgoStat.degree <- function(egor, d, by=NULL, homophily=FALSE, levels=NULL){
   ## if(any(d==0)) warning("degree(0) (isolate) count statistic depends strongly on the specified population network size.")
 

tests/testthat/test-EgoStat.R

@@ -40,7 +40,9 @@ test_that("egostats are close to complete network stats", {
 
     absdiff("a") + absdiff("a", 2) + absdiff(~a + 2*c - exp(d)) + 
     absdiff(function(x) if(is(x, "data.frame")) x[["a"]] + 2*x[["c"]] - exp(x[["d"]]) else (x %v% "a") + 2*(x %v% "c") - exp(x %v% "d")) + 
-
+
+    absdiffcat("a") + absdiffcat("a", levels=-1) + absdiffcat("a", levels=2) +
+
     degree(0) + degree(3) + degree(0:6) +
     degree(0, by="a") + degree(3, by="a") + degree(0:6, by="a") +
     degree(0, by="a", homophily=TRUE) + degree(3, by="a", homophily=TRUE) + degree(0:6, by="a", homophily=TRUE) + degree(0:6, by="a", homophily=FALSE, levels = -1) + 
@@ -132,11 +134,12 @@ test_that("egostats with alter missing data are close to complete network stats"
   f <- ~ edges +
     nodecov("a") +
 
-    nodefactor("a", 0) + nodefactor("a", 1) + nodefactor("a", 2) +
+    nodefactor("a", levels=TRUE) + nodefactor("a", levels=-1) + nodefactor("a", levels=-2) +
 
-    nodematch("a") + nodematch("a", TRUE) + nodematch("a", TRUE, 2) +
+    nodematch("a") + nodematch("a", TRUE) + nodematch("a", TRUE, levels=-2) +
 
     absdiff("a") + absdiff("a", 2) +
+    absdiffcat("a") + absdiffcat("a", levels=-1) + absdiffcat("a", levels=I(2)) +
 
     degree(0) + degree(3) + degree(0:6) +
     degree(0, by="a") + degree(3, by="a") + degree(0:6, by="a") +