Hot answers tagged visualisation
22
I played with this topic a lot some time ago.
You can find some examples here:
Dobrou extensions plugin examples
Dobrou extensions plugin homepage
Using Sporttracks and this plugin, gps tracks can be converted to KML and displayed in Google Earth.
It supports some ideas mentioned here - track coloring based on color gradient, direction arrows and much more.
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21
I've always done it as width. For example you create a buffer around each point that represents speed and then dissolve the buffers into one. Narrow areas indicate bottlenecks.
For an example see: http://www.fmepedia.com/index.php/Bufferer
Of course, you can even color code the buffers before merging them.
For an example see: ...
20
This video should give you a general idea of how to create nice line styles in QGIS with new symbology: "Video tutorial #1: Creating a custom railway style"
More related posts:
"Vector rule editor and polygon line styles in QGIS"
"Advanced Layer Styles in QGIS"
In Tomtom data for example, you have an attribute called frc that can be used to classify ...
19
Good question.
Geography, and later GISc have been struggling to incorporate 4th dimension since Torsten Hägerstrand brought time into geographic research.
Couple of things from the top of my head:
One of the solutions is to use 'space time aquarium' where in 3D space you can use X and Y to represent location in space and Y to represent time.
Two names ...
18
As always, it depends on your objectives and the nature of the data. For completely mapped data, a powerful tool is Ripley's L function, a close relative of Ripley's K function. Lots of software can compute this. ArcGIS might do it by now; I haven't checked. CrimeStat does it. So do GeoDa and R. An example of its use, with associated maps, appears in
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17
A simple and efficient way is to color the segments depending on their speed. For example, "fast" segments can be displayed in green and "slow" segments in red (other colors can be chosen of course).
Example on an orienteering-running GPS trace using the software Chmuk:
Another example with the software quickroute:
The parts of the route where the ...
17
The INSPIRE data specifications define some standard styles for portrayal of topographic data (transport network, hydrography, administrative units, etc.). See for example the section "11.Portrayal" of this document for hydrography.
If you are looking for standards for the representation of style, see SLD and GSS.
17
I would say you can't include all that data on one map and have it make any sense. I'd recommend you think along the lines of Tufte's principle of small multiples, having multiple smaller maps of the same area, each using a different variable. Example: http://www.juiceanalytics.com/writing/better-know-visualization-small-multiples/
Even then, you have ...
15
The problem is to figure out how much to bend the arcs to enhance their visual resolution.
Here's one solution (among the many possible). Let's consider all the arcs emanating from a common origin. The arcs get most crowded here. To separate them the best, let's arrange it so they spread out in equally-spaced angles. It's a problem if we draw straight ...
13
The OpenStreetMap .osm XML data type can be parsed and rendered in a number of software packages. For a somewhat turnkey custom map tile drawer, I suggest: http://tiledrawer.com
--- a product that uses Amazon's EC2 and by Michal Migurski -- who provides other pointers in this thread :)
You might also check out "Build your own OpenStreetMap Server"
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13
Noise mapping a good example of such visualization at the building-level (it is even more detailed, at the facade level). The advantage is obvious: mapping such phenomenon is not possible in 2D. The disadvantage is that is is hard to see the overall noise repartition.
Sources: Noise map of Paris municipality (left) and MITHRA-SIG (right).
13
I'd have to guess that the bottom one was done in some form of Microsoft Visio - which of course is not free. Here are some of those shapes from Visio 2010 that I just found on my install, and they look very similar to the graphic you show:
I have used InkScape for making all sorts of technical diagrams, posters, and flyers. It's completely FOSS, and if ...
12
I think you may be interested in work described as time geography, and you may want to use search terms such as space-time-path or space-time-cube. In the space-time-cube technique I would imagine you could still use color to represent velocity of the movements, although it is inherently represented in the space/time distance between nodes on your path.
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12
Creating great circles could give you the desired effect.
Maybe something like discussed on http://postgis.refractions.net/pipermail/postgis-users/2008-February/018620.html
Update:
I've followed up on this idea in "Visualizing Global Connections". It's a purely PostGIS-based solution using reprojection to create arcs.
SELECT ST_Transform(
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11
It is not possible to show efficiently so much data on a single map. Two possibilities:
Produce 6 maps,
Analyse your data to classify your regions, and display the result of the classification. A principal component analysis can help to determine the most important correlations within your variable. This method has been used to produce this synthetic map:
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11
It's a great question. One standard set of iconic markers with which everyone in the world is familiar is their country's set of street signs: stop, yield, crossing ahead, etc. I hope the point of such standardization is immediately obvious.
Note that the actual meanings of many of the highway symbols are not intrinsic: they must be learned (especially ...
10
For thematic maps, the handy Colorbrewer has an ArcGIS plug-in, ColorTool
The built-in styles also contain lots of professionally selected color palettes and ramps that you could repurpose for other needs. To look at the styles without having to dink around in ArcMap, you can view them in PDF form
10
Since you have multiple objects being tracked I would go with using color to differentiate objects and instead of colour to show speed, I'd use thin lines perpendicular to the direction of movement illustrating 10 second intervals (say). Closer lines = slower. Not the best sketch below, but you get the idea:
10
You can record the position of the vehicle with a regular time interval and gradually fade out old time points. Adding a line at each point whose length is representative of the speed can help too. Below is an example from Microsoft Research. It's quite easy to see the relative speed of different countries in this graph.
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10
Polygonize your raster shape via the Raster-to-polygon tool in the raster menu. Use your field value as category
Click on categorized styling, classify and double click on the symbol. Then select "SVG-FILL" and the following dialog should appear with some basic SVG icons coming with QGIS.
Choose an icon and remember to set the border line ("simple line") ...
9
There are different methods depending on what you want to accomplish, how much data you have, and how pretty you want it. Your idea is a good idea and would probably work well. Of course another obvious answer is to show all of the relationships all the time but that would add a lot of visual clutter. Perhaps a nice compromise is to always show all of the ...
9
From someone who is part of the "GE Generation"
Atmospheric Data
When you are visualizing atmospheric features, it is important to see a vertical profile of the atmosphere.
Sub-surface data
When working sub-surface (bore holes, or earthquakes as shown below). In the image below, magnitude is mapped to pin size, but depth is mapped (inverted) to ...
9
Usually, choropleth maps display densities and not populations. Displaying population makes the result too dependent on the subdivision. So, option 2 is certainly the most appropriate one.
To define the density classes, this document describes common methodologies. The quantile method is usually applied for choropleth maps.
8
Two possibilities, depending on how much of the OSM data itself you want to edit.
One is to host your own OSM server, with a copy of the data that you can freely edit. The software for this is known as "The Rails Port", can be found here: http://wiki.openstreetmap.org/wiki/The_Rails_Port
Another is to use OSM's tiled cartography as a background for your ...
8
You might be interested in my slides from a SXSW panel on geotemporal visualization. While they don't cover every single approach, they do a pretty good job of offering examples for the most common approaches (note that many of these examples require a browser with SVG or Canvas support, so not IE<9):
Showing time as a line on a map
Showing time as map ...
8
How about arrow symbols? Length of arrow = speed of the object at that location. You also get direction for free. And the whole thing is very intuitive -- no need to glance over at the legend to remind yourself of the interpretation.
It's used all the time for wind-speed maps, but there's nothing saying you can't symbolize objects this way too: ...
8
I think I would go for something in the direction of Trevesys suggestion but only with dots instead. Longer between the dots means faster and closer between them means slower.
It is easy to think of the speed like, high speed should get a more powerful visualization, but I am tempted to think the reverse because the symbol is bounded to a special place on ...
8
I think both your points sum up the A to the Q quite well.
Some examples where its useful:
Flood Analysis
Viewshed Analysis (including shadow analysis)
Sub-terrain analysis (Geology, oil exploration)
I think a key problem with 3D is the 'Google Earth Generation' (I just made that up), think that displaying everything in 3D is a good idea.
This kind of ...
8
Environmental investigations are inherently three dimensional. As a simple illustration of what some environmental data might look like, here is an image from a simple 3D GIS I created (using VRML) in the '90s.
The box-like structures are buildings in an office park. The multi-colored "straws" display subsurface geologic readings taken every one to five ...
8
I agree that small multiples are probably a good way to approach this problem. To supplement the map I would also suggest a scatterplot matrix of your variables, which would identify bivariate correlations. While you lose the geographic aspect of your data, it is much simpler to visualize the relationships between variables in a scatterplot than it is to ...
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