Adds support for contours (d3.geom.contour) and cardinal spline interpolation.
I've extended cardinal spline interpolation to d3.svg.area, and added closed
basis spline interpolation. The spline tension is now set using a named
method, and closed splines can be generated using basis-closed and
cardinal-closed, respectively.
This commit also includes Jeff's nifty clustered force-directed graph example!
If the same element were selected multiple times, then the transition would be
cleared on the associated node, causing `tx` to be undefined. We now abort the
transition in this case, rather than causing a JavaScript error.
The renaming of attributes is totally not worth the hassle of maintaining an
externs file (or using the awkward `foo["bar"]` syntax). The file size
reduction from the advanced optimizations was negligible, besides!
This computes the projected area (in square pixels) of the given GeoJSON
object. This is useful for producing choropleth maps that area normalized to
the visible area.
Two new XHR utilities are included in this commit for fetching XML and HTML
data. The latter can be used to scrape data from websites that don't support a
more suitable API (such as JSON or XML), conveniently using the W3C DOM API
including selectors.
Parsing HTML is surprisingly tricky, as browser support for it is poorly
standardized. It's possible to embed the HTML in the current document or an
iframe, but that runs embedded scripts and loads external resources (images,
stylesheets), which is a security hazard!
Our approach uses the DOM Level 2 Range API, and the nonstandard
createContextualFragment method, which is supported by major browsers.
Strangely, WebKit (Chrome & Safari) can only access the body of the loaded
HTML document, whereas Firefox parses the whole document.
We now use the same property accessors (startAngle, endAngle and radius) for
two source and target objects. Note that you don't have to structure your data
hierarchically; you can define a source and target accessor that restructures
the data on the fly.
These are symmetric operators for splitting and merging (blending) arrays. The
split operator is useful for line and area charts where some of the data
points may be undefined; split the data into subarrays and render each as its
own line or area. This commit also fixes a bug in d3.svg.line when the data
array is empty.
I'll add support for other types of splines shortly. These classes now also
support constants for the various x and y properties. Also, the area class can
now be used with a variable baseline (y0) for creating streamgraphs. I will
update the current streamgraph demo to use d3.svg.area in a future commit.
Transitions created within the end event of an earlier transition now reuse
the same transition ID, which allows staged transitions to continue in
parallel even if the a later transition has been scheduled. Now that
transitions support remove, we can dispatch transition end events even if the
active transition does not own the element.
Michael Bostock
Jeffrey Heer