From f44d8094e12a9162e490e6906e65ef3bcbad86b5 Mon Sep 17 00:00:00 2001
From: mpadge <mark.padgham@email.com>
Date: Thu, 11 Aug 2022 11:39:35 +0200
Subject: [PATCH] add add_nodes_to_graph fn; closes #103

---
 DESCRIPTION                            |  2 +-
 NAMESPACE                              |  1 +
 R/match-points.R                       | 97 ++++++++++++++++++++++++++
 codemeta.json                          |  2 +-
 man/add_nodes_to_graph.Rd              | 46 ++++++++++++
 man/compare_heaps.Rd                   |  1 +
 man/dodgr_flowmap.Rd                   |  1 +
 man/dodgr_full_cycles.Rd               |  1 +
 man/dodgr_fundamental_cycles.Rd        |  1 +
 man/dodgr_insert_vertex.Rd             |  1 +
 man/dodgr_sample.Rd                    |  1 +
 man/dodgr_sflines_to_poly.Rd           |  1 +
 man/dodgr_vertices.Rd                  |  1 +
 man/match_points_to_graph.Rd           |  1 +
 man/match_points_to_verts.Rd           |  1 +
 man/match_pts_to_graph.Rd              |  1 +
 man/match_pts_to_verts.Rd              |  1 +
 man/merge_directed_graph.Rd            |  1 +
 man/summary.dodgr_dists_categorical.Rd |  1 +
 man/write_dodgr_wt_profile.Rd          |  1 +
 20 files changed, 161 insertions(+), 2 deletions(-)
 create mode 100644 man/add_nodes_to_graph.Rd

diff --git a/DESCRIPTION b/DESCRIPTION
index 45a0f7760..cb2a9d68d 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: dodgr
 Title: Distances on Directed Graphs
-Version: 0.2.14.086
+Version: 0.2.14.087
 Authors@R: c(
     person("Mark", "Padgham", , "mark.padgham@email.com", role = c("aut", "cre")),
     person("Andreas", "Petutschnig", role = "aut"),
diff --git a/NAMESPACE b/NAMESPACE
index e50034a3b..5f8db9635 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -5,6 +5,7 @@ S3method(weight_streetnet,default)
 S3method(weight_streetnet,sc)
 S3method(weight_streetnet,sf)
 export("%>%")
+export(add_nodes_to_graph)
 export(clear_dodgr_cache)
 export(compare_heaps)
 export(dodgr_cache_off)
diff --git a/R/match-points.R b/R/match-points.R
index e2332ceba..21087e500 100644
--- a/R/match-points.R
+++ b/R/match-points.R
@@ -160,3 +160,100 @@ match_points_to_graph <- function (graph, xy, connected = FALSE) {
 
     match_pts_to_graph (graph, xy, connected = connected)
 }
+
+#' Insert new nodes into a graph, breaking edges at point of nearest
+#' intersection.
+#'
+#' The "id" value of each edge to be divided through insertion of new points is
+#' modified to produce two new "id" values with suffixes "_A" and "_B". This
+#' routine presumes graphs to be `dodgr_streetnet` object, with geographical
+#' coordinates.
+#'
+#' @inheritParams match_pts_to_graph
+#' @return A modified version of `graph`, with additional edges formed by
+#' breaking previous edges at nearest penpendicular intersections with the
+#' points, `xy`.
+#' @family misc
+#' @export
+add_nodes_to_graph <- function (graph, xy) {
+
+    index <- match_pts_to_graph (graph, xy)
+
+    gr_cols <- dodgr_graph_cols (graph)
+    gr_cols <- unlist (gr_cols [which (!is.na (gr_cols))])
+    graph_std <- graph [, gr_cols] # standardise column names
+    names (graph_std) <- names (gr_cols)
+
+    # Expand index to include all potentially duplicated edges:
+    index <- lapply (seq_along (index), function (i) {
+        out <- which (
+            (graph_std$from == graph_std$from [index [i]] &
+                graph_std$to == graph_std$to [index [i]]) |
+                (graph_std$from == graph_std$to [index [i]] &
+                    graph_std$to == graph_std$from [index [i]])
+        )
+        cbind (rep (i, length (out)), out)
+    })
+    index <- data.frame (do.call (rbind, index))
+    names (index) <- c ("n", "index")
+
+    genhash <- function (len = 10) {
+        paste0 (sample (c (0:9, letters, LETTERS), size = len), collapse = "")
+    }
+
+    edges_to_split <- graph_std [index$index, ]
+    graph_to_add <- graph [index$index, ]
+
+    graph_std <- graph_std [-index$index, ]
+    graph <- graph [-index$index, ]
+
+    edges_to_split$n <- index$n
+
+    edges_split <- lapply (unique (index$n), function (i) {
+
+        edges_to_split_i <- edges_to_split [which (edges_to_split$n == i), ]
+
+        d_wt <- edges_to_split_i$d_weighted / edges_to_split_i$d
+        t_wt <- edges_to_split_i$time_weighted / edges_to_split_i$time
+        t_scale <- edges_to_split_i$time / edges_to_split_i$d
+
+        new_edges_i <- lapply (seq (nrow (edges_to_split_i)), function (e) {
+
+            edge_i <- rbind (edges_to_split_i [e, ], edges_to_split_i [e, ])
+            edge_i$to [1] <- edge_i$from [2] <- genhash ()
+            edge_i$xto [1] <- xy$x [i]
+            edge_i$yto [1] <- xy$y [i]
+            edge_i$xfr [2] <- xy$x [i]
+            edge_i$yfr [2] <- xy$y [i]
+
+            xy_i <- data.frame (
+                x = c (edge_i [1, "xfr"], edge_i [1, "xto"], edge_i [2, "xto"]),
+                y = c (edge_i [1, "yfr"], edge_i [1, "yto"], edge_i [2, "yto"])
+            )
+            dmat <- geodist::geodist (xy_i)
+            edge_i$d [1] <- dmat [1, 2]
+            edge_i$d [2] <- dmat [2, 3]
+
+            edge_i$d_weighted <- edge_i$d * d_wt
+            edge_i$time <- edge_i$d * t_scale
+            edge_i$time_weighted <- edge_i$time * t_wt
+
+            edge_i$edge_id <- paste0 (edge_i$edge_id, "_", LETTERS [e])
+
+            return (edge_i)
+        })
+
+        return (do.call (rbind, new_edges_i))
+    })
+
+    edges_split <- do.call (rbind, edges_split)
+
+    # Then match edges_split back on to original graph:
+    graph_to_add <- graph_to_add [edges_split$n, ]
+    gr_cols <- gr_cols [which (!is.na (gr_cols))]
+    for (g in seq_along (gr_cols)) {
+        graph_to_add [, gr_cols [g]] <- edges_split [[names (gr_cols) [g]]]
+    }
+
+    return (rbind (graph, graph_to_add))
+}
diff --git a/codemeta.json b/codemeta.json
index 1c32b48d7..b708d42ad 100644
--- a/codemeta.json
+++ b/codemeta.json
@@ -7,7 +7,7 @@
   "codeRepository": "https://github.com/ATFutures/dodgr",
   "issueTracker": "https://github.com/ATFutures/dodgr/issues",
   "license": "https://spdx.org/licenses/GPL-3.0",
-  "version": "0.2.14.086",
+  "version": "0.2.14.087",
   "programmingLanguage": {
     "@type": "ComputerLanguage",
     "name": "R",
diff --git a/man/add_nodes_to_graph.Rd b/man/add_nodes_to_graph.Rd
new file mode 100644
index 000000000..25a655a81
--- /dev/null
+++ b/man/add_nodes_to_graph.Rd
@@ -0,0 +1,46 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/match-points.R
+\name{add_nodes_to_graph}
+\alias{add_nodes_to_graph}
+\title{Insert new nodes into a graph, breaking edges at point of nearest
+intersection.}
+\usage{
+add_nodes_to_graph(graph, xy)
+}
+\arguments{
+\item{graph}{A \code{dodgr} graph with spatial coordinates, such as a
+\code{dodgr_streetnet} object.}
+
+\item{xy}{coordinates of points to be matched to the vertices, either as
+matrix or \pkg{sf}-formatted \code{data.frame}.}
+}
+\value{
+A modified version of \code{graph}, with additional edges formed by
+breaking previous edges at nearest penpendicular intersections with the
+points, \code{xy}.
+}
+\description{
+The "id" value of each edge to be divided through insertion of new points is
+modified to produce two new "id" values with suffixes "_A" and "_B". This
+routine presumes graphs to be \code{dodgr_streetnet} object, with geographical
+coordinates.
+}
+\seealso{
+Other misc: 
+\code{\link{compare_heaps}()},
+\code{\link{dodgr_flowmap}()},
+\code{\link{dodgr_full_cycles}()},
+\code{\link{dodgr_fundamental_cycles}()},
+\code{\link{dodgr_insert_vertex}()},
+\code{\link{dodgr_sample}()},
+\code{\link{dodgr_sflines_to_poly}()},
+\code{\link{dodgr_vertices}()},
+\code{\link{match_points_to_graph}()},
+\code{\link{match_points_to_verts}()},
+\code{\link{match_pts_to_graph}()},
+\code{\link{match_pts_to_verts}()},
+\code{\link{merge_directed_graph}()},
+\code{\link{summary.dodgr_dists_categorical}()},
+\code{\link{write_dodgr_wt_profile}()}
+}
+\concept{misc}
diff --git a/man/compare_heaps.Rd b/man/compare_heaps.Rd
index 57f827798..a6c175c74 100644
--- a/man/compare_heaps.Rd
+++ b/man/compare_heaps.Rd
@@ -38,6 +38,7 @@ compare_heaps (graph, nverts = 1000, replications = 1)
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
 \code{\link{dodgr_fundamental_cycles}()},
diff --git a/man/dodgr_flowmap.Rd b/man/dodgr_flowmap.Rd
index 5df6521ef..85b527cdd 100644
--- a/man/dodgr_flowmap.Rd
+++ b/man/dodgr_flowmap.Rd
@@ -42,6 +42,7 @@ dodgr_flowmap (graph_undir)
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_full_cycles}()},
 \code{\link{dodgr_fundamental_cycles}()},
diff --git a/man/dodgr_full_cycles.Rd b/man/dodgr_full_cycles.Rd
index 56c11e873..ff156b54b 100644
--- a/man/dodgr_full_cycles.Rd
+++ b/man/dodgr_full_cycles.Rd
@@ -39,6 +39,7 @@ cyc2 <- dodgr_full_cycles (net)
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_fundamental_cycles}()},
diff --git a/man/dodgr_fundamental_cycles.Rd b/man/dodgr_fundamental_cycles.Rd
index 8e7aa0dad..fdd7dd7f2 100644
--- a/man/dodgr_fundamental_cycles.Rd
+++ b/man/dodgr_fundamental_cycles.Rd
@@ -58,6 +58,7 @@ cyc <- dodgr_fundamental_cycles (graph, verts)
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/dodgr_insert_vertex.Rd b/man/dodgr_insert_vertex.Rd
index 9d7718d49..e0b4ec7db 100644
--- a/man/dodgr_insert_vertex.Rd
+++ b/man/dodgr_insert_vertex.Rd
@@ -43,6 +43,7 @@ nrow (graph2) # new edges added to graph2
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/dodgr_sample.Rd b/man/dodgr_sample.Rd
index 8686d27ed..d6d936b0c 100644
--- a/man/dodgr_sample.Rd
+++ b/man/dodgr_sample.Rd
@@ -33,6 +33,7 @@ nrow (dodgr_vertices (graph)) # 200
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/dodgr_sflines_to_poly.Rd b/man/dodgr_sflines_to_poly.Rd
index 67960e7c5..45ee24c4d 100644
--- a/man/dodgr_sflines_to_poly.Rd
+++ b/man/dodgr_sflines_to_poly.Rd
@@ -25,6 +25,7 @@ fundamental cycles within the \code{LINESTRING} objects.
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/dodgr_vertices.Rd b/man/dodgr_vertices.Rd
index d3c9c69fc..8ff3880d0 100644
--- a/man/dodgr_vertices.Rd
+++ b/man/dodgr_vertices.Rd
@@ -27,6 +27,7 @@ v <- dodgr_vertices (graph)
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/match_points_to_graph.Rd b/man/match_points_to_graph.Rd
index 8fbb28190..74dcdd1c0 100644
--- a/man/match_points_to_graph.Rd
+++ b/man/match_points_to_graph.Rd
@@ -42,6 +42,7 @@ graph [edges, ] # The edges of the graph closest to `xy`
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/match_points_to_verts.Rd b/man/match_points_to_verts.Rd
index 07024c3a5..46785bc7e 100644
--- a/man/match_points_to_verts.Rd
+++ b/man/match_points_to_verts.Rd
@@ -43,6 +43,7 @@ pts # names of those vertices
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/match_pts_to_graph.Rd b/man/match_pts_to_graph.Rd
index 62fc404b0..f494ebb6b 100644
--- a/man/match_pts_to_graph.Rd
+++ b/man/match_pts_to_graph.Rd
@@ -48,6 +48,7 @@ graph [edges, ] # The edges of the graph closest to `xy`
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/match_pts_to_verts.Rd b/man/match_pts_to_verts.Rd
index 8f120f5c8..21924339b 100644
--- a/man/match_pts_to_verts.Rd
+++ b/man/match_pts_to_verts.Rd
@@ -43,6 +43,7 @@ pts # names of those vertices
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/merge_directed_graph.Rd b/man/merge_directed_graph.Rd
index 8e00a0f4b..65ab3b7bc 100644
--- a/man/merge_directed_graph.Rd
+++ b/man/merge_directed_graph.Rd
@@ -46,6 +46,7 @@ nrow (graph_undir) # the latter is much smaller
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/summary.dodgr_dists_categorical.Rd b/man/summary.dodgr_dists_categorical.Rd
index 4b031c517..98b7f0216 100644
--- a/man/summary.dodgr_dists_categorical.Rd
+++ b/man/summary.dodgr_dists_categorical.Rd
@@ -19,6 +19,7 @@ Transform a result from 'dodgr_dists_categorical' to summary statistics
 }
 \seealso{
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},
diff --git a/man/write_dodgr_wt_profile.Rd b/man/write_dodgr_wt_profile.Rd
index ccc60bd92..d4e37d1c4 100644
--- a/man/write_dodgr_wt_profile.Rd
+++ b/man/write_dodgr_wt_profile.Rd
@@ -21,6 +21,7 @@ Write the \code{dodgr} street network weighting profiles to a local
 \link{weight_streetnet}
 
 Other misc: 
+\code{\link{add_nodes_to_graph}()},
 \code{\link{compare_heaps}()},
 \code{\link{dodgr_flowmap}()},
 \code{\link{dodgr_full_cycles}()},