Rather than producing separate files for each module, the default build now
produces a single file. This should encourage better page-load performance as
the files were relatively small. Also, it's easier to deal with only one file
rather than many, especially if you're not quite sure what the dependencies are.
You may still create minimized builds, if you don't want every feature.
This commit also demotes the chart components to the examples directory, rather
than keeping them as part of the core library. As always, D3 is not a charting
library, and these were ever only intended to serve as examples.
The greatArc class is the new name for greatCircle, which actually represents
great arcs. Meanwhile, a new greatCircle class is for great circles. The new
greatCircle class replaces the old clip class, providing clipping and resampling
functionality (using greatArc internally). This isn't backwards-compatible, but
I may forgo the major version number bump in light of the fact that greatCircle
was just added, and not used in any (official) examples or documented.
Note that the Werner projection is a special case with standard parallel
at 90°N, and the Sinusoidal projection is also a special case with
standard parallel at 0°N.
This can be used to process output from d3.geo.clip to ensure clipped
polygons are correctly curved.
The "n" option has been replaced with precision, which denotes the
approximate angular length of great-circle segments. This is much
faster than using a fixed number of segments, particularly when
processing a large number of polygons, only a few of which may have
edges long enough to warrant being converted into a geodesic.
This can be used with d3.geo.path.clip to clip the input coordinates of
geographical shapes using a given origin and angular radius, e.g. for
hemispherical or near-hemispherical views. Geodesics are inserted as
necessary.
This also includes a minor bugfix and test for d3.geo.path: the last
coordinate of Polygon features was being included unnecessarily
(MultiPolygon already handled this correctly).
Higher-order programming! This makes it more akin to d3.svg.chord i.e.
it can take "d" and "i" arguments. Thanks for the suggestion, Mike!
Also made "n" and "radius" configurable, too.
Can be used to generate great circle paths. Similar to R's
geosphere.gcIntermediate (in which I discovered a bug, while writing the
test case for this!)
Includes d3.geo.greatcircle().distance for computing the shortest geo
path distance using the Haversine formula.
For a tutorial on using great circles, see:
http://flowingdata.com/2011/05/11/how-to-map-connections-with-great-circles/
Mike Bostock
Jason Davies