How can we make a map with MapPoint and the Census Bureau?

March 6, 2008 3:52 PM

We've got Census data in Excel from the Census Bureau. We've got a state all mapped out by census tract (using the unprojected boundary files, as they don't provide the projected files). What we don't have is a way to download values from the data files into the census tracts they correspond to. Is there some way to do this that we don't know? Will we have to write a program?

I'm sorry, but I'm really NOT a programmer, so if my question on this topic sounds stupid, well, it's because I kind of am.

And I've seen this question, and while it's helpful, I don't think that that any of the responses offer what I need.

We've got the data. And we've got MapPoint 2006. But we don't have the jillions of hours it will take to hand-code each individual census tract (there's a LOT of them!!)

We've been trying with ArcGIS mapping onto GoogleMaps (which converst the SHP into KML, doesn't it?), but that's even worse (at least we can program the census tracts onto MapPoint). Are we hopeless? Should we just go back to colored markers and construction paper?

So what do we do? Hire laborers from the 3d world? Do we write a program? Or is there some special functionality on MapPoint that we're missing.

posted by deejay jaydee to computers & internet (9 comments total)

And feel free to MeFi mail me with any suggestions, snark, or simple mockery. I can take it!
posted by deejay jaydee at 3:54 PM on March 6, 2008

There should be a common data field in your Census data and the boundary file, most likely the census tract number. Do a JOIN on the two tables using the common field, which will append the census data to the boundary file table.
posted by InfidelZombie at 4:00 PM on March 6, 2008

What InfidelZombie said. Also, you can define the projection for a layer in ArcGIS under, I believe, Properties-->Source if you know what projection it ought to be in.
posted by agentofselection at 4:24 PM on March 6, 2008

Oh, for a join to work, the two columns will have to be the same variable type (string, double integer, etc.) If Arc is inferring the wrong type for your Excel data, try importing it into an access database and defining the variable type there, then loading the .dbf into Arc instead of the .xls
posted by agentofselection at 4:26 PM on March 6, 2008

One more: I was wrong about how to define a projection. Here's instructions.
posted by agentofselection at 4:36 PM on March 6, 2008

I've been recently taking a course on GIS in which we use census material as examples, and apparently there's a major problem with the boundary files provided by the census people because they don't have a common field between the shapefile for the boundaries and the excell table. The instructor said something about having to write a VBS[?] script to make a matching field.

That said, if you have a full version of ArcGIS, you may be able to download the shapefile for the relevant census track boundary data from ESRI - they produce a copy with a field that matches the data from the census.
posted by jb at 6:04 PM on March 6, 2008

Okay, I've just downloaded local Census track boundaries for Census 2000 - you can get them by county. You can download a whole state at once, but you get a different shapefile for each county. You can also get census block level data and boundary files. (I don't remember which is the bigger, tract or block).

Looking at the table for the SHP file, it has a field called STFID which should match a field in the census data called GeoID_2. You'll have to do a join, and export it as a new SHP file, etc, but the whole process takes about 10 minutes. It looks like the file also comes without it's projection system defines, but it's actually GCS North American Datum 1983 - you can just tell the file what it is suposed to be in ArcGIS.

There is a tutorial on how to do this HERE.

I'm not logged in as an ArcGIS user or anything, so this data should be freely available to anyone. Maybe it's meant to sell ArcGIS, since that's the format.

If you do have a copy of ArcGIS, is there a reason you want to use another map making program? ArcGIS makes okay looking maps - the only reason not to use it is cost of purchase.
posted by jb at 6:22 PM on March 6, 2008

More info on the ESRI shapefiles - generally they are GCS North American Datum 1983, unless you are working in Hawaii or Alaska.
posted by jb at 6:45 PM on March 6, 2008

Oops, I linked that already. Oh well, can't have too many links.
posted by jb at 6:46 PM on March 6, 2008