osgschl.R

library(sf)

## Linking to GEOS 3.5.1, GDAL 2.2.1, proj.4 4.9.2

## multipolygon, not the greatest example for real world path data
## but gets the idea
x <- read_sf(system.file("shape/nc.shp", package="sf"))[1:2, ]
library(spbabel)

## basically fortify but in a broader context ...
d <- spbabel::sptable(x)
library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

## want attributes from x?
d <- inner_join(as_tibble(x) %>% 
                  ## put desired x attributes here
                  dplyr::transmute(NAME, object_ = row_number()), 
                d)

## Joining, by = "object_"

library(ggplot2)
## note the coordinate attributes are x_, y_, object_, branch_ 
## which are analogs of gg's  x, y, id, group 
ggplot(d, aes(x_, y_, group = branch_, colour = NAME)) + 
  geom_path(arrow = arrow(length=unit(0.30,"cm"), ends="first", type = "closed"))