d3.nest- 分層地分組數組元素。
nest.entries- 返回一組鍵-值元組
nest.key- 在嵌套層級中添加一個級別。
nest.map- 返回一個關聯數組。
nest.rollup- 為葉子值指定一個匯總函數。
nest.sortKeys- 按照鍵排序葉子嵌套級別。
nest.sortValues- 按照值排序葉子嵌套級別。
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
