Database Reference
In-Depth Information
domain:[0,29] },
{name:"y",range:"height",nice:true,
domain:{data:"values",field:"data"}},
],
axes:[
{type:"x",scale:"x"},
{type:"y",scale:"y"}
],
The primary element of note in this last section is the linking of the data
series to the scale in the
domain
element. This structure is called a
DataRef
, and it usually consists of a data series, identified by the
data
element, and a field accessor that is defined by the
field
element. When
data is added to Vega an array that looks like this:
[0,1]
It is translated into a “Vega compatible” format that looks like this:
[{index:0,data:0},{index:1,data:1}]
The field accessors operate on this transformed data and expect the
inclusion of the
index
and
data
fields to operate correctly. More
complicated data structures can be accessed using the usual JavaScript dot
notation.
Defining “marks” in the specification specifies the type of chart drawn for a
given series. Like NVD3, defining multiple marks draws multiple elements
within a single chart. In this case, only a
rect
mark is rendered to draw the
bar chart:
marks:[{
type:"rect",
from:{data:"values"},
properties:{
enter:{
fill:{value:"#ccc"},
stroke:{value:"#aaa"}
},
update:{