Welcome to MapForums!

When you are signed in, this message, the ads in this row, and the red-underlined link ads all go away.

## Point interpolation

This is a discussion on Point interpolation within the MapPoint Desktop Discussion forums, part of the Map Forums category; I'm looking for a way to take two points with a road between, and use the roads in MapPoint to ...

1. Senior Member Black Belt
Join Date
Jul 2002
Posts
5,137

## Point interpolation

I'm looking for a way to take two points with a road between, and use the roads in MapPoint to fill in the road with either pushpins, or even better, directly outputted to a .csv file. Is this kind of thing possible?

Thanks,

2. You are skirting very close to the EULA conditions, depending on exactly what you are trying to do.

The road data is copyrighted. In order for it to be sold at such a low price (yes the cost of MapPoint is a bargain when you look at the data that is included), there have th be restrictions in how the data is used. Eg. you can't extract the road networks with a decent degree of accuracy.

How would I go about it?
Create a route between the two points. The route will have location points along it for each set of directions. These are not exactly on the route, but are a suitable location to zoom on for that leg of the journey. Performing a bit of maths can give you some points that are closer, but accuracy can still be a problem.
Another method is to scan convert the route by using the distance measuring method from the route to a series of test locations.

Richard

3. Senior Member Black Belt
Join Date
Jul 2002
Posts
5,137

Let me explain what I'm trying to do a little more. Part of what we do at our company is tracking vehicles with GPS units. We currently have in our system nodes at basically every intersection in the country. The problem comes when we get a ping from a vehicle that is on a road in our system, but instead of locking on to the proper node it will map to a node that is closer to the vehicle's position on the road, which is physically closer.

Linear interpolation will only go so far in this case, probably around 99% of the time it will be sufficient, but there are many cases where roads would then overlap.

In any case, I see what you mean about how to do it directly in MapPoint. Unfortunately we need to to do it for every road in our system I don't really have 10 years to finish things that way.

One more quick question; in case my superiors choose to open their wallets and purchase more detailed data, what would you recommend getting and what software would you use for it?

Thanks,

4. Yes it could be slow in MapPoint - even with a bit of clever programming!

I don't have much experience with road networks in the US, but I think ArcView/ArcGIS has some of this?

If you don't need a map, is there a national database you could buy?
If I was in the UK and didn't need a working off-the-shelf application, I would buy the Ordnance Survey (UK's national mapping agency)'s "MasterMap" product which includes road information. Load it into a relational database, and then query accordingly.

Richard