数组

• d3.ascending - compare two values for sorting.
• d3.descending - compare two values for sorting.
• d3.min - find the minimum value in an array.
• d3.max - find the maximum value in an array.
• d3.extent - find the minimum and maximum value in an array.
• d3.sum - compute the sum of an array of numbers.
• d3.mean - compute the arithmetic mean of an array of numbers.
• d3.median - compute the median of an array of numbers (the 0.5-quantile).
• d3.quantile - compute a quantile for a sorted array of numbers.
• d3.variance - compute the variance of an array of numbers.
• d3.deviation - compute the standard deviation of an array of numbers.
• d3.bisect - search for a value in a sorted array.
• d3.bisectRight - search for a value in a sorted array.
• d3.bisectLeft - search for a value in a sorted array.
• d3.bisector - bisect using an accessor or comparator.
• d3.shuffle - randomize the order of an array.
• d3.permute - reorder an array of elements according to an array of indexes.
• d3.zip - transpose a variable number of arrays.
• d3.transpose - transpose an array of arrays.
• d3.pairs - returns an array of adjacent pairs of elements.
• d3.keys - list the keys of an associative array.
• d3.values - list the values of an associated array.
• d3.entries - list the key-value entries of an associative array.
• d3.merge - merge multiple arrays into one array.
• d3.range - generate a range of numeric values.
• d3.nest - group array elements hierarchically.
• nest.key - add a level to the nest hierarchy.
• nest.sortKeys - sort the current nest level by key.
• nest.sortValues - sort the leaf nest level by value.
• nest.rollup - specify a rollup function for leaf values.
• nest.map - evaluate the nest operator, returning an associative array.
• nest.entries - evaluate the nest operator, returning an array of key-values tuples.
• d3.map - a shim for ES6 maps, since objects are not hashes!
• map.has - returns true if the map contains the specified key.
• map.get - returns the value for the specified key.
• map.set - sets the value for the specified key.
• map.remove - removes the entry for specified key.
• map.keys - returns the map’s array of keys.
• map.values - returns the map’s array of values.
• map.entries - returns the map’s array of entries (key-values objects).
• map.forEach - calls the specified function for each entry in the map.
• map.empty - returns false if the map has at least one entry.
• map.size - returns the number of entries in the map.
• d3.set - a shim for ES6 sets, since objects are not hashes!
• set.has - returns true if the set contains the specified value.
• set.add - adds the specified value.
• set.remove - removes the specified value.
• set.values - returns the set’s array of values.
• set.forEach - calls the specified function for each value in the set.
• set.empty - returns true if the set has at least one value.
• set.size - returns the number of values in the set.