flows visualisation with arcs or flowmaps

[e-kotov]

Hello @walkerke , I wonder if it is possible to add support for flow visualisation with both or either of:

• arcs https://svelte-maplibre.vercel.app/examples/deckgl-arcs , implemented in https://symbolixau.github.io/mapdeck/reference/add_arc.html

• flowmaps https://github.com/FlowmapBlue/FlowmapBlue ; https://github.com/FlowmapBlue/flowmapblue.R

[bt-maps]

See also https://github.com/JohMast/flowmapper

[e-kotov]

See also https://github.com/JohMast/flowmapper

yes, see also, but these are static. I do not suggest implementing the algorithm used in {flowmapper}.

I was thinking since the underlying tech of {mapgl}, {deckgl}, {mapdeck}, {flowmapblue} are essentially the same (correct me if i'm wrong, but it's all based on deck.gl one way or another), adding arcs or even better, flowmaps, to {mapgl} (which to me seems like the most ergonomic solution with many nice features) may be relatively easy.

[bt-maps]

Agreed that deck.gl/flowmap.gl is preferred. Deck.gl layer sources would be a great feature. Py-maplibregl has this functionality for shiny for python. https://eodagmbh.github.io/py-maplibregl/ flowmapper algorithm is from flowmapblue, so some additional work would be needed to visualize with mapgl using sf objects

…

On Thu, Sep 5, 2024, 6:23 PM Egor Kotov ***@***.***> wrote: See also https://github.com/JohMast/flowmapper yes, see also, but these are static. I do not suggest implementing the algorithm used in {flowmapper}. I was thinking since the underlying tech of {mapgl}, {deckgl}, {mapdeck}, {flowmapblue} are essentially the same (correct me if i'm wrong, but it's all based on deck.gl one way or another), adding arcs or even better, flowmaps, to {mapgl} (which to me seems like the most ergonomic solution with many nice features) may be relatively easy. — Reply to this email directly, view it on GitHub <#37 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABALIN3ZHIC6FHUBXKXRQZ3ZVDKU7AVCNFSM6AAAAABNOUABAWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGMZSG4ZTAMZQGY> . You are receiving this because you commented.Message ID: ***@***.***>

[walkerke]

This would be interesting to consider. Those types of maps are available in deck.gl, which is not part of Mapbox GL JS or MapLibre GL JS by default. So we'd need to build out a deck.gl interface to accomplish that (which is what py-maplibregl has done). I'm not sure what the development lift for that would be.

In the meantime, the rdeck package (https://github.com/qfes/rdeck) is also a really nice interface to deck.gl (though unfortunately not on CRAN). You might consider taking a look at it for flow mapping.

[walkerke]

Arc visualization support may be coming soon to Mapbox, which means we'll be able to support it here. See: mapbox/mapbox-gl-js#3993 (comment)

[e-kotov]

Non-interactive flows are now mappable with {mapgl}, thanks to the latest update in {flowmapper} by @JohMast!

Code and discussion over here:
JohMast/flowmapper#7 (comment)

[walkerke]

This is excellent @e-kotov!

[e-kotov]

@walkerke

draft implementation here: https://github.com/e-kotov/mapgl/tree/flow

# remotes::install_github("e-kotov/mapgl")
# install.packages("flowmapblue")
library(flowmapblue)
data(ch_locations)
data(ch_flows)
library(mapgl)


ch_locations_sf <- sf::st_as_sf(
  ch_locations,
  coords = c("lon", "lat"),
  crs = 4326
)

# Create a map with flowmap layer
map <- maplibre(
  bounds = ch_locations_sf,
  zoom = 3
) %>%
  add_flowmap(
    id = "us-flows",
    locations = ch_locations,
    flows = ch_flows,
    color_scheme = "Teal",
    dark_mode = TRUE,
    animation_enabled = FALSE,
    fade_enabled = TRUE,
    clustering_enabled = TRUE,
    location_labels_enabled = FALSE
  )

# Display the map
map

fl2.mp4

There's still quite a lot of work needs to be done to make it work well and be fully customizeable (e.g. like here https://visgl.github.io/flowmap.gl/ ), but I think this is a good start.

[e-kotov]

Some more progress on this - better blending modes to match the beauty of https://visgl.github.io/flowmap.gl/ , yet this is optional, as to not interfere with other layers users might want to use with flow maps.

progress.mp4

cc FYI @ilyabo @JohMast

[walkerke]

looking great!

[walkerke]

closing this as @e-kotov your implementation is looking quite impressive externally!

[e-kotov]

closing this as @e-kotov your implementation is looking quite impressive externally!

But it's not finished yet... There's still some cleanup work to do before PR.