Convert Graph to Linestrings

Convert a graph data frame with node coordinates to an sf object with LINESTRING geometries.

Usage

linestrings_from_graph(graph_df, crs = 4326)

Arguments

graph_df

A data frame representing a graph with columns: FX, FY, TX, TY (starting and ending node coordinates), and optionally other columns to preserve.

crs

Numeric or character (default: 4326). Coordinate reference system to assign to the output sf object.

Value

An sf data frame with LINESTRING geometry, containing all columns from graph_df except FX, FY, TX, and TY. Each row represents an edge as a LINESTRING connecting the from-node (FX, FY) to the to-node (TX, TY).

Details

This function is the inverse operation of linestrings_to_graph. It:

• Creates LINESTRING geometries from node coordinates (FX, FY, TX, TY)

• Removes the coordinate columns from the output

• Preserves all other columns from the input graph data frame

• Returns an sf object suitable for spatial operations and visualization

See also

linestrings_to_graph flownet-package

Examples

library(flownet)
library(sf)

# Convert segments data frame to sf LINESTRING object
segments_sf <- linestrings_from_graph(africa_segments)
class(segments_sf)
#> [1] "sf"         "data.frame"
head(segments_sf)
#> Simple feature collection with 6 features and 3 fields
#> Geometry type: LINESTRING
#> Dimension:     XY
#> Bounding box:  xmin: -17.44759 ymin: 14.40844 xmax: -16.63849 ymax: 21.28569
#> Geodetic CRS:  WGS 84
#>   passes  gravity gravity_rd                       geometry
#> 1     59 93.20669  67.218731 LINESTRING (-17.44759 14.69...
#> 2      6 59.98582  45.491608 LINESTRING (-17.44759 14.69...
#> 3     48 61.68941  42.121072 LINESTRING (-17.04861 14.70...
#> 4     11 31.51728  25.097660 LINESTRING (-17.04861 14.70...
#> 5     63  4.09779   2.981159 LINESTRING (-17.03345 20.93...
#> 6     10 20.13822  14.737626 LINESTRING (-16.96602 14.72...

# \donttest{
# Plot segments colored by route importance
plot(segments_sf["passes"])

# }