D3 now supports Sizzle, preferring Sizzle to the native Selectors API if Sizzle
is available. Sizzle internally uses the native Selectors API and thus this
should have minimal performance implications; also, it allows you to use Sizzle
proprietary extensions such as ":first".
This commit also restricts the definition of the enter selection so that only
append and insert operations are defined. The other operations were generally
unsupported anyway, and it cleans up the code to have separate implementations
for insert and append. (I might enable additional operations in the future, such
as `filter`, `sort` and `each`, but this seems like a reasonable first pass.)
The `symbol` class can be used to generate dot symbols for scatterplots. This
commit also fixes a couple bugs with negative-domain log and pow scales, as well
as tick generation.
This method can be used for computing the bounding box of arbitrary GeoJSON
objects. This commit also fixes a bug in d3.geo.path, such that it will accept
any GeoJSON object, rather than requiring GeoJSON feature objects.
This uses d3.geo.path to compute the projected area (in square pixels) of each
county in the choropleth. It also usees d3.behavior.zoom to add geometric pan
and zoom.
Includes, as the first behavior, a pan & zoom behavior. The canvas can be panned
by dragging the mouse, and zoomed using the mousewheel (or by double-click). By
listening to redraw events, users can decide whether to implement geometric
zooming (such as by setting the "transform" attribute on an `svg:g` element) or
semantic zooming (by changing the domain of a scale object and repositioning
elements).
This commit also includes two bug fixes. The `d3.format` class now properly
groups thousands of negative numbers, and supports the sign specifier. The
unicode minus symbol \u2212 is used for negative values. The `d3.scale.pow`
class now properly handles negative numbers, as well.
First, always coerce the tween target value (the value of the style or attribute
at the end of the transition) to a string. This guarantees that the correct
interpolator is chosen, and avoids a null dereference.
Second, default color channels to zero rather than undefined, so as to avoid NaN
channel values if there is an error parsing the color. This can occur, say, if
the background color of a div is unset and defaults to "rgba(0, 0, 0, 0)".
The data join is now specified as a single function of data, as with all other
properties. This allows the key to be computed on the previously-bound data,
rather than requiring the key to be serialized into the DOM (say, as an
attribute). In the case that there is no previously-bound data, it is still
possible to access the associated node as the `this` context.
The `enter` operator no longer performs an append. For symmetry with the `exit`
operator, you must call `append` after obtaining the entering selection. This
requires a tiny bit more code, but should make the code more clear. Also, it
provides an opportunity to use a different instantiation operator, such as the
new `insert` operator. This takes a second argument, which is a selector for the
insert-before reference element. For example, the selector ":first-child" will
prepend nodes.
The `empty` operator allows you to query whether a selection is empty (i.e.,
contains zero matching nodes).
You can now override the scale interpolator by calling the `interpolate` method.
One particularly useful interpolator is the new `d3.interpolateRound`, which is
like `interpolateNumber`, except that it returns integers. This makes it easier
to produce a scale that outputs exact pixel values, and avoid antialiasing
artifacts.
For convenience, the quantitative scales have a `rangeRound` method which sets
the range and the interpolator at the same time. Similarly, a `rangeRoundBands`
has been added to the ordinal scale.
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.