Hotspot heatmap for event clusters

[Mattkmmr]

It would be interesting to plot event clusters for a family or ancestors or descendants or just a filter match result in form of a hotspot heatmap. Currently in the map view category the views only show markers for the events, but not the density of the event clusters. I think it would allow new and interesting ways to represent areas of interest or event clusters.

Sample picture of what I mean with a hotspot heatmap:

@SNoiraud You worked a lot on the map views, right? Do you know if this would be possible to implement/render in Gramps?

[PLegoux]

Good idea. This kind of plot of event clusters could allow to plot another kind of map like this one I’ve seen yesterday in a video from French Genealogy Federation (FFG) virtual symposium:

From: https://youtu.be/zG7PV1MuWog

It links ancient family event clusters to current clusters (industrial migration from countries to cities) viewing this only using big arrows between clusters (time logic).

[Mattkmmr]

Yes a combination of a heatmap and arrows added with GIMP/Photoshop would be a nice way to explain movements. I have researched some lines where I have already found most or all descendants.

[SNoiraud]

@Mattkmmr

You worked a lot on the map views, right? Do you know if this would be possible to implement/render in Gramps?

All is possible. The problems are the resources (developers, time, …)

[Mattkmmr]

@SNoiraud

All is possible. The problems are the resources (developers, time, …)

Well I meant is it reasonable possible to create for Gramps? I don’t know which libraries could be used for that or already being used and would allow that. Like if everything would have to be created from scratch, it’s probably a better idea to create some export and use an external program, since nice maps are cool, but not the main focus of Gramps.

[StoltHD]

Just a tip for a workaround…

You might export the places to a CSV file, import them to SAGA (GIS) or QGIS, and create the map overlay there and save them in the right format for Gramps…

I don’t know if the module in Gramps read all of the settings from those files, but it should be possible?

[Mattkmmr]

@StoltHD

You might export the places to a CSV file, import them to SAGA (GIS) or QGIS, and create the map overlay there and save them in the right format for Gramps…

Thank you for the tip. I’ll try that.

[GeorgeWilmes]

The python package “folium” can create heat maps, optionally with time sliders. Here is an example.

[Mattkmmr]

@GeorgeWilmes

The python package “folium” can create heat maps, optionally with time sliders

The folium package is great, but I recognized a problem with the heat maps: They only show the density of places, not the density of the events. I tried to change the weight for the places depending on the number of events, but it seems to have no to very little effect.

I afraid I probably need chloropleth maps with devision on municipal or parish level to create what I was looking for, but it is much more difficult to get geodata for them as well as exporting the event places from my place hierarchy instead of using the coordinates.

My current workaround is using circle markers colored depending on the number of events.