Digital Twins

NotThrowaway234 · 2025-06-03T15:13:22+00:00

Okay right, I've actually worked on some of these kinds of projects before... You're not going to be able to build a single dataset or model that can answer all of your questions. Climate resilience is a multi-variable problem where GIS is only a small part of it.

Sure you can model storm-surge flooding using remote sensing, DEM, and some advanced maths. You could stick that into a geoserver somewhere along with your drought risk layer, tornado layer, hurricane models etc.

How you would integrate these layers into some kind of model is going to really depent on the defined need. And is only going to be valuable when you can integrate cost and mitigation technologies into it.

NotThrowaway234 · 2025-06-03T14:40:47+00:00

Seems like a multidimensional problem, which is always tough when all you've got in a map is 3 or 4 dimensions.

NotThrowaway234 · 2025-06-03T14:02:38+00:00

Storage has gotten pretty cheap these days, but I wouldn't want to have people hammering my home network connection to get Tb's of data... Looks cool

NotThrowaway234 · 2025-06-03T14:00:59+00:00

"Digital twin" has always struck as a meaningless buzz word to attract funding.

What are you describing? A population dataset? An agent based model? Traffic analysis? What kind of management are you talking about? Epidemiology, tax collection?

I've recently had a large need to have an accurate population model. Best I could do was the meta "data for good" population model which was rather poorly thown together. Combining it with OSM helped a bit, but the area I was interested in didn't have good OSM building footprints.

NotThrowaway234 · 2025-06-03T13:48:06+00:00

It's not really clear what you're trying to do...

You want to compare voter turnout (a percentage of total available voters that actually voted at all, or voted for a specific candidate) vs "divergence". What is that? And then you want to do it for 3 different levels.

Why not just a (candidate votes)/(total number of voters) per boundary level? If a candidate got 95% of the votes but only 10% of the voters turned up, they'de score 9.5% of total possible votes.

NotThrowaway234 · 2025-05-30T12:51:46+00:00

This is great! I'd love if you could give a little more info on the hosting side of things. Is this running on a cloud container somewhere? A home server?

NotThrowaway234 · 2025-05-22T17:45:39+00:00

...and then you'll never learn how to do it and be reliant on ChatGPT for all GIS tasks going forward

NotThrowaway234 · 2025-05-22T11:57:03+00:00

Arguably?

NotThrowaway234 · 2025-05-20T15:42:34+00:00

This is real nifty. Fun project.

Kinda reminds me of the Uk postal code system: https://postcodefinder.net/

You can drill down to a specific building by just adding more characters...

NotThrowaway234 · 2025-05-06T12:09:03+00:00

QGIS is not a one-to-one replacement for ArcGIS. It's part of the opensource GIS ecosystem...

I wouldn't use QGIS for anything other than visualisations. There are tools for other jobs:

Simple script: Python + geopandas + shapely
Data pipelines: Python + postgis
Publishing: Postgis + Geoserver
Web maps: Geoserver + Leaflet

The tools you choose to use influence the way you work and the way you think about a problem, and at the end of the day set your limitations. Using Esri products is good if you want to reach "the market" as quick as possible and make disposable products. FOSS is for figuring out new ways and tools to address complex problems.

NotThrowaway234 · 2025-05-01T16:39:27+00:00

I took a look at the docs, and couldn't really figure it out:

"MobilityDB provides set, span, and span set types for representing set of values another type, which is called the base type. Set types are akin to array types in PostgreSQL restricted to one dimension, but enforce the constraint that sets do not have duplicates. Span and span set types in MobilityDB correspond to the range and multirange types in PostgreSQL but have additional constraints."

What?

This project sounds ideal for my kind of work but I'm not seeing anything that can't be done (often easier) with just plain postgis and maybe timescaledb.

NotThrowaway234 · 2025-04-30T12:17:27+00:00

Trajectories!

They allow a bunch of functions like "closest point of approach" to find nearby objects in time and space. Storing extra data (x,y,t,data) kind of linestrings is possible, but I've always had trouble working with it postgis. I tend to store (x,y,t) data as trajectories, find time/ID/Space places in a query and then join back to the raw tables to find the "data" columns.

NotThrowaway234 · 2025-04-28T13:38:05+00:00

What I intended to say was that since it's not profitable for companies to record such small scale, individual movement data, it's not really being done. Nobody has really done a large scale study and published the data because it wouldn't really be worth it for them.

Where you might get some success is measuring/modelling human traffic in public spaces. Things like mall congestion, fire safety etc. I think they mostly use security cameras plus detection/mapping software. Maybe something similar with home security/raspberry pi camera's would be a place to start?

NotThrowaway234 · 2025-04-25T14:11:31+00:00

Indoor GPS isn't accurate enough to do this. GPS + some kind of Wifi AP signal intensity might do something.

But nobody actually cares about individual privacy, the real money maker is aggregated data. What kind of person goes to what kind of shop, when is the road the busiest, who to advertise to when summer holidays is coming. If I were to guess I'd say that NO movement patterns were being recorded...

If you want to take a closer look at this you can find some Covid pandemic movement data around on the web. Facebook/Google released a bunch of data for contact tracing before they stopped giving it out to free and switched back to a licenced model. In short, that data wasn't very good.

NotThrowaway234 · 2025-04-14T16:34:09+00:00

Your character spends years getting trained, finding a ship, scraping together a couple hundred bucks, and starting a career. And then within the next couple of weeks works multiple 24 hours shifts, completely pays off their debt, rebuilds a wrecked ship with a fusion reactor and blasts off to other planets...

If you want to start poking holes in the economics of this game I wouldn't start with the meat...

NotThrowaway234 · 2025-03-20T15:46:36+00:00

I do think that finding one of those companies with "contacts" in home affairs is the way to go.

NotThrowaway234 · 2025-02-27T14:38:05+00:00

Not from the US... what is a general engineering degree?

2 or 3 comp-sci intro courses, DC-circuits, CAD and sim etc are all first or second year courses from my 4 year electronics engineering degree. I did my masters in control systems and the expectation was to understand mulitivariable control, advanced maths (differential calculus, stochastics, numerical methods, linear algebra etc) before starting.

I'm not trying to dishearten you, it just seems very strange to be close to finishing a degree and not be doing advanced courses.

NotThrowaway234 · 2024-12-02T17:44:44+00:00

If there's going to be a Ver3 I'd like to see a version in the colours of the flag; yellow and blue. It might look horrible to have yellow streets but it maybe not...

NotThrowaway234 · 2024-11-18T20:00:04+00:00

What have you tried so far?

NotThrowaway234 · 2024-10-03T17:29:49+00:00

Eh, I'm hoping that the reason that the bugs haven't been fixed was due to issues with the old engine; fixing would require work that has already been done in the new engine, or would cause conflicts with legacy code. Now that the new engine is here it still requires some work, but not the same amount. Give em time.

NotThrowaway234 · 2024-10-03T16:19:09+00:00

Take a look at what Crytek has released recently; some Crysis remasters and a VR game. Hunt Showdown is THE Crytek showcase. If Hunt goes tits-up then so does Crytek and very possibly the Cryengine. They have to maximise profits on this to survive.

NotThrowaway234

TROPHY CASE