SampledProperty

new Cesium.SampledProperty(type, derivativeTypes)
engine/Source/DataSources/SampledProperty.js 159

A Property whose value is interpolated for a given time from the provided set of samples and specified interpolation algorithm and degree.
Name Type Description
type number | Packable The type of property.
derivativeTypes Array.<Packable> optional When supplied, indicates that samples will contain derivative information of the specified types.
Examples:
//Create a linearly interpolated Cartesian2
const property = new Cesium.SampledProperty(Cesium.Cartesian2);

//Populate it with data
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:00:00.00Z'), new Cesium.Cartesian2(0, 0));
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-02T00:00:00.00Z'), new Cesium.Cartesian2(4, 7));

//Retrieve an interpolated value
const result = property.getValue(Cesium.JulianDate.fromIso8601('2012-08-01T12:00:00.00Z'));
//Create a simple numeric SampledProperty that uses third degree Hermite Polynomial Approximation
const property = new Cesium.SampledProperty(Number);
property.setInterpolationOptions({
    interpolationDegree : 3,
    interpolationAlgorithm : Cesium.HermitePolynomialApproximation
});

//Populate it with data
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:00:00.00Z'), 1.0);
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:01:00.00Z'), 6.0);
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:02:00.00Z'), 12.0);
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:03:30.00Z'), 5.0);
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:06:30.00Z'), 2.0);

//Samples can be added in any order.
property.addSample(Cesium.JulianDate.fromIso8601('2012-08-01T00:00:30.00Z'), 6.2);

//Retrieve an interpolated value
const result = property.getValue(Cesium.JulianDate.fromIso8601('2012-08-01T00:02:34.00Z'));
See:

Members

backwardExtrapolationDuration : number
engine/Source/DataSources/SampledProperty.js 349

Gets or sets the amount of time to extrapolate backward before the property becomes undefined. A value of 0 will extrapolate forever.
Default Value: 0

backwardExtrapolationType : ExtrapolationType
engine/Source/DataSources/SampledProperty.js 331

Gets or sets the type of extrapolation to perform when a value is requested at a time before any available samples.
Default Value: ExtrapolationType.NONE

readonly definitionChanged : Event
engine/Source/DataSources/SampledProperty.js 241

Gets the event that is raised whenever the definition of this property changes. The definition is considered to have changed if a call to getValue would return a different result for the same time.

derivativeTypes : Array.<Packable>
engine/Source/DataSources/SampledProperty.js 261

Gets the derivative types used by this property.

forwardExtrapolationDuration : number
engine/Source/DataSources/SampledProperty.js 313

Gets or sets the amount of time to extrapolate forward before the property becomes undefined. A value of 0 will extrapolate forever.
Default Value: 0

forwardExtrapolationType : ExtrapolationType
engine/Source/DataSources/SampledProperty.js 295

Gets or sets the type of extrapolation to perform when a value is requested at a time after any available samples.
Default Value: ExtrapolationType.NONE

interpolationAlgorithm : InterpolationAlgorithm
engine/Source/DataSources/SampledProperty.js 283

Gets the interpolation algorithm to use when retrieving a value.
Default Value: LinearApproximation

interpolationDegree : number
engine/Source/DataSources/SampledProperty.js 272

Gets the degree of interpolation to perform when retrieving a value.
Default Value: 1

readonly isConstant : boolean
engine/Source/DataSources/SampledProperty.js 227

Gets a value indicating if this property is constant. A property is considered constant if getValue always returns the same result for the current definition.

type : *
engine/Source/DataSources/SampledProperty.js 251

Gets the type of property.

Methods

addSample(time, value, derivatives)
engine/Source/DataSources/SampledProperty.js 583

Adds a new sample.
Name Type Description
time JulianDate The sample time.
value Packable The value at the provided time.
derivatives Array.<Packable> optional The array of derivatives at the provided time.

addSamples(times, values, derivativeValues)
engine/Source/DataSources/SampledProperty.js 627

Adds an array of samples.
Name Type Description
times Array.<JulianDate> An array of JulianDate instances where each index is a sample time.
values Array.<Packable> The array of values, where each value corresponds to the provided times index.
derivativeValues Array.<Array> optional An array where each item is the array of derivatives at the equivalent time index.
Throws:

addSamplesPackedArray(packedSamples, epoch)
engine/Source/DataSources/SampledProperty.js 708

Adds samples as a single packed array where each new sample is represented as a date, followed by the packed representation of the corresponding value and derivatives.
Name Type Description
packedSamples Array.<number> The array of packed samples.
epoch JulianDate optional If any of the dates in packedSamples are numbers, they are considered an offset from this epoch, in seconds.

equals(other) → boolean
engine/Source/DataSources/SampledProperty.js 791

Compares this property to the provided property and returns true if they are equal, false otherwise.
Name Type Description
other Property optional The other property.
Returns:
true if left and right are equal, false otherwise.

getSample(index) → JulianDate|undefined
engine/Source/DataSources/SampledProperty.js 683

Retrieves the time of the provided sample associated with the index. A negative index accesses the list of samples in reverse order.
Name Type Description
index number The index of samples list.
Returns:
The JulianDate time of the sample, or undefined if failed.

getValue(time, result) → object
engine/Source/DataSources/SampledProperty.js 371

Gets the value of the property at the provided time.
Name Type Default Description
time JulianDate JulianDate.now() optional The time for which to retrieve the value. If omitted, the current system time is used.
result object optional The object to store the value into, if omitted, a new instance is created and returned.
Returns:
The modified result parameter or a new instance if the result parameter was not supplied.

removeSample(time) → boolean
engine/Source/DataSources/SampledProperty.js 733

Removes a sample at the given time, if present.
Name Type Description
time JulianDate The sample time.
Returns:
true if a sample at time was removed, false otherwise.

removeSamples(time)
engine/Source/DataSources/SampledProperty.js 762

Removes all samples for the given time interval.
Name Type Description
time TimeInterval The time interval for which to remove all samples.

setInterpolationOptions(options)
engine/Source/DataSources/SampledProperty.js 544

Sets the algorithm and degree to use when interpolating a value.
Name Type Description
options object optional Object with the following properties:
Name Type Description
interpolationAlgorithm InterpolationAlgorithm optional The new interpolation algorithm. If undefined, the existing property will be unchanged.
interpolationDegree number optional The new interpolation degree. If undefined, the existing property will be unchanged.
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