mark padgham

Reprex of the new function in action: ``` r library(dodgr) # load the Accra street network from somewhere else, then ... net % dodgr_contract_graph () v

I had to write this function, because I just couldn't calculate all the layers for our [current work](https://github.com/atfutures/who3) the old way - R kept on violently crashing. It wasn't (directly)...

TODO: - [ ] Document this function properly in the main [`dodgr_flows` vignette](https://atfutures.github.io/dodgr/articles/flows.html) Issue can then be closed, as the functionality is fully developed

There's a conference paper [here](http://sss9sejong.or.kr/paperpdf/mmd/SSS9_2013_REF057_P.pdf), which shows how this really is a purely spatial syntax phenomenon, requiring initial conversion of a graph into its dual representation. Bill Hillier's fabulously compelling...

So maybe "angular betweenness" is not actually the thing we want; rather an option to route paths between two points based on sum of angular change, as in [`sDNA`](https://sdna-open.readthedocs.io/en/latest/analysis-spec.html#distance-metric). That...

The short answer is that that graph can't be contracted in the `dodgr` sense. There is nothing that lies between the termini and the junction vertices. This results in the...

Make current top-left (`gkZcTf`) redundant by inserting extra `from("gcKcTf") - to("a")` ``` > edges dodgr::dodgr_contract_graph(edges) $graph # A tibble: 5 x 4 from_id to_id edge_id d 1 SpeI4O a a123461...

That last point is really important: The way I see it, there would / should be a general need for an independent `sanitize_graph()` function to insert implicit vertices. This shouldn't...

"Absolutely agree." The question is the underlying graph representation fed to `sanitize_graph`. And I guess and hope that the answer there is `SC`. So maybe for the moment I'll park...

Centrality can already be calculated with `dodgr_flows` and a unit flow matrix, but this is **not** the same as `igraph::centrality`, because the latter simply uses the graph with unit edge...