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Class: ChangeDecimalToValue

Defined in: src/animation/numbers/index.ts:139

ChangeDecimalToValue - Animate a DecimalNumber to a specific target value.

This is a convenience animation that automatically uses the DecimalNumber's current value as the starting point. It's equivalent to ChangingDecimal with startValue set to the current value.

Example​

// Create a decimal number at 42
const num = new DecimalNumber({ value: 42 });

// Animate to 100 (starts from current value 42)
timeline.add(new ChangeDecimalToValue(num, { targetValue: 100 }));

// With custom duration and rate function
timeline.add(new ChangeDecimalToValue(num, {
  targetValue: 0,
  duration: 2,
  rateFunc: easeInOut
}));

Extends​

Constructors​

Constructor​

new ChangeDecimalToValue(decimalNumber, options): ChangeDecimalToValue

Defined in: src/animation/numbers/index.ts:152

Parameters​

decimalNumber​

DecimalNumber

options​

ChangeDecimalToValueOptions

Returns​

ChangeDecimalToValue

Overrides​

Animation.constructor

Properties​

_hasBegun​

protected _hasBegun: boolean = false

Defined in: src/animation/Animation.ts:49

Track if begin() has been called

Inherited from​

Animation._hasBegun

_isFinished​

protected _isFinished: boolean = false

Defined in: src/animation/Animation.ts:46

Whether the animation has finished

Inherited from​

Animation._isFinished

_startTime​

protected _startTime: number = null

Defined in: src/animation/Animation.ts:43

Time when the animation started (set by Timeline)

Inherited from​

Animation._startTime

decimalNumber​

readonly decimalNumber: DecimalNumber

Defined in: src/animation/numbers/index.ts:141

The DecimalNumber being animated

duration​

readonly duration: number

Defined in: src/animation/Animation.ts:37

Duration of the animation in seconds

Inherited from​

Animation.duration

mobject​

readonly mobject: Mobject

Defined in: src/animation/Animation.ts:34

The mobject being animated

Inherited from​

Animation.mobject

rateFunc​

readonly rateFunc: RateFunction

Defined in: src/animation/Animation.ts:40

Rate function controlling the animation's pacing

Inherited from​

Animation.rateFunc

remover​

remover: boolean = false

Defined in: src/animation/Animation.ts:55

If true, the scene will remove this mobject after the animation finishes. Used by FadeOut (like Python manim's remover=True).

Inherited from​

Animation.remover

Accessors​

startTime​

Get Signature​

get startTime(): number

Defined in: src/animation/Animation.ts:236

Get the start time of this animation (set by Timeline)

Returns​

number

Set Signature​

set startTime(time): void

Defined in: src/animation/Animation.ts:243

Set the start time of this animation (used by Timeline)

Parameters​
time​

number

Returns​

void

Inherited from​

Animation.startTime

Methods​

begin()​

begin(): void

Defined in: src/animation/numbers/index.ts:165

Called when the animation starts. Captures the current value as the starting point.

Returns​

void

Overrides​

Animation.begin

cleanUpFromScene()​

cleanUpFromScene(scene): void

Defined in: src/animation/Animation.ts:141

Hook called by Scene after the animation finishes, before the next play(). Default: removes mobject if remover is set (FadeOut, Write({remover:true})). Override for animations that need to mutate scene membership — e.g. ReplacementTransform swaps source for target.

Parameters​

scene​

AnimationScene

Returns​

void

Inherited from​

Animation.cleanUpFromScene

finish()​

finish(): void

Defined in: src/animation/numbers/index.ts:188

Called when the animation ends. Ensures the final value is set exactly.

Returns​

void

Overrides​

Animation.finish

getStartValue()​

getStartValue(): number

Defined in: src/animation/numbers/index.ts:197

Get the start value of the animation

Returns​

number

getSubAlpha()​

protected getSubAlpha(alpha, index, count, lagRatio): number

Defined in: src/animation/Animation.ts:161

Manim CE's get_sub_alpha: remaps a global progress alpha into the local progress of family member index (of count) under a lagRatio stagger. With lagRatio <= 0 (or a single member), every member tracks alpha directly. Subclasses that stagger across a mobject's family (e.g. Create) should index this by familyMembersWithPoints(), never by rendering-layer primitives.

Parameters​

alpha​

number

index​

number

count​

number

lagRatio​

number

Returns​

number

Inherited from​

Animation.getSubAlpha

getTargetValue()​

getTargetValue(): number

Defined in: src/animation/numbers/index.ts:204

Get the target value of the animation

Returns​

number

interpolate()​

interpolate(alpha): void

Defined in: src/animation/numbers/index.ts:175

Interpolate the decimal value at the given alpha.

Parameters​

alpha​

number

Progress from 0 (start) to 1 (end), after rate function applied

Returns​

void

Overrides​

Animation.interpolate

isFinished()​

isFinished(): boolean

Defined in: src/animation/Animation.ts:197

Check if the animation has finished

Returns​

boolean

Inherited from​

Animation.isFinished

reset()​

reset(): void

Defined in: src/animation/Animation.ts:206

Reset the animation to its initial state. Restores the mobject to its pre-animation visual state so that re-seeking (especially backward) produces correct results.

Returns​

void

Inherited from​

Animation.reset

update()​

update(_dt, currentTime): void

Defined in: src/animation/Animation.ts:174

Update the animation for the current frame.

Parameters​

_dt​

number

Time delta since last frame (unused, but available for subclasses)

currentTime​

number

Current time in the timeline

Returns​

void

Inherited from​

Animation.update