Nest Tutorial and examples

参考网址以及API

d3.nest- 分层地分组数组元素。

nest.entries- 返回一组键-值元组

nest.key- 在嵌套层级中添加一个级别。

nest.map- 返回一个关联数组。

nest.rollup- 为叶子值指定一个汇总函数。

nest.sortKeys- 按照键排序叶子嵌套级别。

nest.sortValues- 按照值排序叶子嵌套级别。

Examples

data.csv

Symbol,Price,Date,Time,Change,Volume

"AA",39.48,"6/11/2007","9:36am",-0.18,181800

"AIG",71.38,"6/11/2007","9:36am",-0.15,195500

"CAT",62.58,"6/11/2007","9:36am",-0.46,935000

"AA",98.31,"6/11/2007","9:36am",+0.12,104800

"CAT",53.08,"6/11/2007","9:36am",-0.25,360900

"CAT",78.29,"6/11/2007","9:36am",-0.23,225400

Simple one level nest