Stack<K, T> class Stacks

Stacking converts lengths into contiguous position intervals.

For example, a bar chart of monthly sales might be broken down into a multi-series bar chart by category, stacking bars vertically and applying a categorical color encoding. Stacked charts can show overall value and per-category value simultaneously; however, it is typically harder to compare across categories as only the bottom layer of the stack is aligned. So, chose the stack order carefully, and consider a streamgraph (see stackOffsetWiggle). (See also grouped charts.)

Like the Pie generator, the stack generator does not produce a shape directly. Instead it computes positions which you can then pass to an Area generator or use directly, say to position bars.

Constructors

Stack.new(num value(T, K, int, Iterable<T>))

Constructs a new stack generator with the given value accessor.

Stack.withConstants(num value)

Constructs a new stack generator with the given value number.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

keys ↔ List<K> Function(Stack<K, T>, Iterable<T>, [List<Object?>?])

The keys accessor;

getter/setter pair

offset ↔ void Function(List<List<List<num>>>, List<int>)

Given the generated series list and the order index list, it is then responsible for updating the lower and upper values in the series list.

getter/setter pair

order ↔ Iterable<int> Function(List<List<List<num>>>)

Given the generated series list, it must return an list of numeric indices representing the stack order.

getter/setter pair

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

value ↔ num Function(T, K, int, Iterable<T>)

The value accessor.

getter/setter pair

Methods

call(Iterable<T> data, [List<Object?>? args]) → List<StackSeries<K, T>>

Generates a stack for the given list of data and returns an list representing each series.

constKeys(List<K> keys) → void

Defines the Stack.keys-accessor as a constant function that always returns the specified value.

constValue(num value) → void

Defines the Stack.value-accessor as a constant function that always returns the specified value.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

withDefaults<K>([num value(Map<K, num>, K, int, Iterable<Map<K, num>>)?]) → Stack<K, Map<K, num>>

Equivalent to Stack.new, except that if value is not specified, its default is used.