blankblank blank


Archive for the 'data' Category Page 3 of 19



Easy Heat Maps From Spreadsheet Data With OpenHeatMap

The OpenHeatMap site lets you create heat maps and choropleths from uploaded spreadsheet data (CSV format), or Google Docs Spreadsheet data (which makes it continuously updatable). It supports location coding by latitude/longitude coordinates, or by a large number of name/code attributes (e.g. address, FIPS code, zip code, state, province, country). And as a bonus, you can also have time as a variable, letting you create animated heatmaps or choropleths. Here’s a snapshot of a time-animation of US unemployment by county (see the live map here):

ohm1

There’s a gallery of sample maps, some of which are embeddable, like the map below of fast-food locations in the US. It’s still a little buggy; the map on the gallery page lets you select between McDonalds, Subway, and Chik-Fil-A, while this embedded map doesn’t show those options.

If you’re willing to dive deep into Javascript, you can create fairly sophisticated online maps allowing the choice between hundreds or even thousands of datasets. Below is a snapshot of the World Data Bank Explorer map from the Gallery; this map lets you choose from over 1000 different demographic/economic datasets, and offers animated views over time:

ohm2

But you’ll need to dive deep into Javascript to create such a sophisticated map; there’s a documentation wiki, but the available documentation is a bit sparse. Basic maps are pretty simple to create, though, and the data upload page offers links to sample datasets (Google Docs spreadsheet links) that you can create sample maps with; copying and pasting the Google Docs spreadsheet link addresses into a browser will give you examples of how the data should be formatted.

Here’s a short video from Pete Warden, developer of the site, with a intro to the service:




Basic Google Maps Heat Map

Tixik Heatmaps – Lets you add a basic heat map to a simple Google Maps display. Create a “CSV” file of latitude/longitude pairs, with coordinates separated by a semi-colon, and each pair on a new line:

48.0043953135;0.2025604248

39.7117426603;3.4630966187

42.6976396896;2.8954124451

etc.

(Taken from the sample file).

Put the file online someplace, and then substitute its web address for “CSV_URL” in the Google Maps code below:

var tilelayer = new GTileLayer(new GCopyrightCollection(), 0, 17);
 tilelayer.getTileUrl = function(tile, zoom) {
   return 'http://api.tixik.com/scripts/tile.php?x='+tile.x+'&y='+tile.y+'&zoom='+zoom+'&csv=CSV_URL';
 };
 tilelayer.getOpacity = function() {return 0.7;}
 map.addOverlay(new GTileLayerOverlay(tilelayer));

Add this code to your Google Maps embed code, and get a basic heat map (sample map from Tixik website):

heat1

Fast, simple and basic – not a lot of options. Bit quirky/buggy, too – check out this zoomed-in area, which dropped some of the data (rest of the world looked fine:

heat2

Colors can also vary depending on the browser you use; the examples above are from Chrome, while the same map in Internet Explorer 8 looks like this:

ieheat

For quick and dirty heatmaps with Google Maps, Tixik Heatmaps seems like a decent option. But there’s an option for use with other map backgrounds that’s more flexible in display options, data format, and embeddability; more on that tomorrow.




SurveyMapper 1.2 – Now With Embeddable Polls

Posted not too long ago about SurveyMapper, a free site for geographically-enabled survey polls. Earlier versions only let you link to the poll page at SurveyMapper, but version 1.2 now lets you embed the poll on your own site, like this one I banged out in five minutes. The poll below is active; feel free to submit a response:

Had a problem with scroll bars in the original embed; you’ll need to play not only with the Width/Height inputs on the page that contains the embed code, but also in the embed code itself; try increasing the Width and Height by 50-75. You can also still link directly to the poll page at SurveyMapper if you like. Now if they’d only let you embed mapped poll results on your page …




New Version Of USGS dlgv32 Geodata Viewer Released

The old USGS geodata viewer dlgv32 was the code foundation for the excellent Global Mapper data viewer and format converter. Global Mapper has granted the USGS a license to continue to release a feature-limited version of Global Mapper under the dlgv32 Pro name, primarily as a data viewer.The latest version of dlgv32 Pro was released a few weeks ago, and includes both 32-bit and 64-bit versions.

The main limitations of dlgv32 are the inability to export data, and the limitation of four raster data files loaded at one time; you can get around this latter limitation by putting all the raster files into a single directory, and then using the File => Open All Files in a Directory Tree option. It has import support for virtually any vector and raster data format you can think of, as well as most projections/datums. There’s also access to online raster data sources, including high-resolution Digital Globe imagery (watermarked, with a daily quota), along with USGS topo maps and black-and-white ortho imagery. Additional features include GPS support, measurement tools, and data attribute query tools. The lack of any export capabilities (except perhaps by doing a screen capture), as well as no way to save a workspace, are big minuses, but it’s still worth a look.

HT to Tyson Domer.




GeoCommons Relaunches

Been meaning to post about GeoCommons for quite a while now, and while I’d like to take credit for knowing that they had a major site reconstruction in order, it’s more like I just hadn’t gotten around to it yet. GeoCommons lets you upload and map data in a number of formats:

  • Shapefile
  • KML (upload or web link)
  • Comma-separated variable CSV
  • GeoRSS (upload or web link)
  • RSS / ATOM (web link)

The “Commons” part comes because any data you upload is freely available to anyone else, so this isn’t a site for those who want to keep their data private or control it. Once uploaded, you can plot it in a variety of styles (with help from a Color Brewer color picker), against any number of available backgrounds:

  • Road:OpenStreetMap, Google, Bing, Yahoo, World Bank, MapQuest
  • Aerial: Google, Bing, Yahoo, NASA Blue Marble
  • Hybrid (roads and aerial): Google, Bing, Yahoo
  • Terrain: Google
  • Or a solid background color

Multiple layers can be plotted if desired. Once completed, you can send people to a permanent link at the GeoCommons page to view it, or embed it into a website (like below; feel free to scroll and zoom):


View full map

You can also view the data in 3D using the Google Earth browser plug-in.

I found the map creation process incredibly easy, but the data upload process needs some work. It took me five tries to get this fairly small Arizona faults shapefile uploaded; hopefully these bugs will be ironed out soon. This shapefile data was in geographic coordinates, WGS84; if you have shapefile data in any other coordinate system, you’ll need to upload  a .prj file with it; and if you don’t upload the .shx and .dbf files with your .shp file, it will ask for them. All other data formats have to be in latitude/longitude, WGS84 datum. And it will ask you for a substantial amount of metadata to be associated with the actual data files, although much of that isn’t mandatory.

Any data uploaded to GeoCommons can also be exported in shapefile, KML and CSV formats (Beta ATOM, JSON and Spatialite format export available). The recent release has also added address geocoding, time animation, and “GeoJoining” (connecting names with common datasets). A paid version of the service called GeoIQ offers a bigger feature set, including advanced analytical tools.




Demographic Maps With DataPlace

DataPlace lets you plot one or more demographic factors in a Google Maps interface, and create an embeddable web page widget:

 

Data includes social/ethnic/economic/population/health/etc., and can be plotted at any detail level from census tract all the way up to national; plot multiple parameters on one map, or display two maps side by side with different parameters. Charts, rankings and metrics, too, all embeddable on any website in widget form (like above).

Be warned, though – site is labeled as “Beta” for good reason. Even with a decent help section, figuring out how to do anything is a real chore. And if you’re impatient, avoid this site – it can take several seconds for data selections or map/chart displays to refresh. Very much a work in progress, but there’s good stuff if you’re willing to slog through the difficulties.

Via Free GIS Data blog.




Compare Geographic Areas With “How Big Really”

The previously-covered “Move Outlines” site let you trace a border around a geographical feature, then compare that border size with any other area in the world. The BBC’s Dimensions website (aka How Big Really) is a nice companion site; while it doesn’t let you draw your own border, it has pre-drawn areas covering a number of different topics, like Environmental Disasters:

garbagepatch

Ancient Worlds…

pyramids

Festivals and Spectacles …

burningman

… plus Space, Depth, The War on Terror, The Industrial Age, Battle Of Britain, and Cities In History. Great for getting a sense of scale.

Via Digital Geography.




The Global Peace Index Map

Vision Of Humanity’s Global Peace Index Map displays a choropleth view of the “Global Peace Index” (GPI), a quasi-arbitrary composite index of 23 factors like military expenditure, level of violent crime, number of heavy weapons, and more. More meaningfully, you can also select individual factors for display on the map, along with a time slider that shows how they change from 2007 to 2010; passing your cursor over a country brings a pop-up with the country rank for that factor, along with the GPI rank. There’s also a table at the bottom listing countries listed by factor ranking; you can also download a PDF with a summary of the general data. Here’s the jailed population factor, number of jailed population per 100,000 people:

gpimap

USA is #1! But not in a good way …

There’s a list of 32 “Related Indicators”, economic/demographics/societal, you can plot as well, including some unusual ones like “Hostility to foreigners” , “Willingness to fight”, and “Corruption perceptions”. Coming soon is another section of “Stats on Life”, containing additional factors like “Water availability” and “Government efficiency”.

Via Download Squad.