text: import Cartesian3 from '../Core/Cartesian3.js';
  import Check from '../Core/Check.js';
  import defaultValue from '../Core/defaultValue.js';
  import defined from '../Core/defined.js';
  import DeveloperError from '../Core/DeveloperError.js';
  import Event from '../Core/Event.js';
  import ReferenceFrame from '../Core/ReferenceFrame.js';
  import PositionProperty from './PositionProperty.js';
  import Property from './Property.js';
  import SampledProperty from './SampledProperty.js';
  
      /**
       * A {@link SampledProperty} which is also a {@link PositionProperty}.
       *
       * @alias SampledPositionProperty
       * @constructor
       *
       * @param {ReferenceFrame} [referenceFrame=ReferenceFrame.FIXED] The reference frame in which the position is defined.
       * @param {Number} [numberOfDerivatives=0] The number of derivatives that accompany each position; i.e. velocity, acceleration, etc...
       */
      function SampledPositionProperty(referenceFrame, numberOfDerivatives) {
          numberOfDerivatives = defaultValue(numberOfDerivatives, 0);
  
          var derivativeTypes;
          if (numberOfDerivatives > 0) {
              derivativeTypes = new Array(numberOfDerivatives);
              for (var i = 0; i < numberOfDerivatives; i++) {
                  derivativeTypes[i] = Cartesian3;
              }
          }
  
          this._numberOfDerivatives = numberOfDerivatives;
          this._property = new SampledProperty(Cartesian3, derivativeTypes);
          this._definitionChanged = new Event();
          this._referenceFrame = defaultValue(referenceFrame, ReferenceFrame.FIXED);
  
          this._property._definitionChanged.addEventListener(function() {
              this._definitionChanged.raiseEvent(this);
          }, this);
      }
  
      Object.defineProperties(SampledPositionProperty.prototype, {
          /**
           * 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.
           * @memberof SampledPositionProperty.prototype
           *
           * @type {Boolean}
           * @readonly
           */
          isConstant : {
              get : function() {
                  return this._property.isConstant;
              }
          },
          /**
           * 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.
           * @memberof SampledPositionProperty.prototype
           *
           * @type {Event}
           * @readonly
           */
          definitionChanged : {
              get : function() {
                  return this._definitionChanged;
              }
          },
          /**
           * Gets the reference frame in which the position is defined.
           * @memberof SampledPositionProperty.prototype
           * @type {ReferenceFrame}
           * @default ReferenceFrame.FIXED;
           */
          referenceFrame : {
              get : function() {
                  return this._referenceFrame;
              }
          },
          /**
           * Gets the degree of interpolation to perform when retrieving a value.
           * @memberof SampledPositionProperty.prototype
           *
           * @type {Number}
           * @default 1
           */
          interpolationDegree : {
              get : function() {
                  return this._property.interpolationDegree;
              }
          },
          /**
           * Gets the interpolation algorithm to use when retrieving a value.
           * @memberof SampledPositionProperty.prototype
           *
           * @type {InterpolationAlgorithm}
           * @default LinearApproximation
           */
          interpolationAlgorithm : {
              get : function() {
                  return this._property.interpolationAlgorithm;
              }
          },
          /**
           * The number of derivatives contained by this property; i.e. 0 for just position, 1 for velocity, etc.
           * @memberof SampledPositionProperty.prototype
           *
           * @type {Boolean}
           * @default false
           */
          numberOfDerivatives : {
              get : function() {
                  return this._numberOfDerivatives;
              }
          },
          /**
           * Gets or sets the type of extrapolation to perform when a value
           * is requested at a time after any available samples.
           * @memberof SampledPositionProperty.prototype
           * @type {ExtrapolationType}
           * @default ExtrapolationType.NONE
           */
          forwardExtrapolationType : {
              get : function() {
                  return this._property.forwardExtrapolationType;
              },
              set : function(value) {
                  this._property.forwardExtrapolationType = value;
              }
          },
          /**
           * Gets or sets the amount of time to extrapolate forward before
           * the property becomes undefined.  A value of 0 will extrapolate forever.
           * @memberof SampledPositionProperty.prototype
           * @type {Number}
           * @default 0
           */
          forwardExtrapolationDuration : {
              get : function() {
                  return this._property.forwardExtrapolationDuration;
              },
              set : function(value) {
                  this._property.forwardExtrapolationDuration = value;
              }
          },
          /**
           * Gets or sets the type of extrapolation to perform when a value
           * is requested at a time before any available samples.
           * @memberof SampledPositionProperty.prototype
           * @type {ExtrapolationType}
           * @default ExtrapolationType.NONE
           */
          backwardExtrapolationType : {
              get : function() {
                  return this._property.backwardExtrapolationType;
              },
              set : function(value) {
                  this._property.backwardExtrapolationType = value;
              }
          },
          /**
           * Gets or sets the amount of time to extrapolate backward
           * before the property becomes undefined.  A value of 0 will extrapolate forever.
           * @memberof SampledPositionProperty.prototype
           * @type {Number}
           * @default 0
           */
          backwardExtrapolationDuration : {
              get : function() {
                  return this._property.backwardExtrapolationDuration;
              },
              set : function(value) {
                  this._property.backwardExtrapolationDuration = value;
              }
          }
      });
  
      /**
       * Gets the position at the provided time.
       *
       * @param {JulianDate} time The time for which to retrieve the value.
       * @param {Cartesian3} [result] The object to store the value into, if omitted, a new instance is created and returned.
       * @returns {Cartesian3} The modified result parameter or a new instance if the result parameter was not supplied.
       */
      SampledPositionProperty.prototype.getValue = function(time, result) {
          return this.getValueInReferenceFrame(time, ReferenceFrame.FIXED, result);
      };
  
      /**
       * Gets the position at the provided time and in the provided reference frame.
       *
       * @param {JulianDate} time The time for which to retrieve the value.
       * @param {ReferenceFrame} referenceFrame The desired referenceFrame of the result.
       * @param {Cartesian3} [result] The object to store the value into, if omitted, a new instance is created and returned.
       * @returns {Cartesian3} The modified result parameter or a new instance if the result parameter was not supplied.
       */
      SampledPositionProperty.prototype.getValueInReferenceFrame = function(time, referenceFrame, result) {
          //>>includeStart('debug', pragmas.debug);
          Check.defined('time', time);
          Check.defined('referenceFrame', referenceFrame);
          //>>includeEnd('debug');
  
          result = this._property.getValue(time, result);
          if (defined(result)) {
              return PositionProperty.convertToReferenceFrame(time, result, this._referenceFrame, referenceFrame, result);
          }
          return undefined;
      };
  
      /**
       * Sets the algorithm and degree to use when interpolating a position.
       *
       * @param {Object} [options] Object with the following properties:
       * @param {InterpolationAlgorithm} [options.interpolationAlgorithm] The new interpolation algorithm.  If undefined, the existing property will be unchanged.
       * @param {Number} [options.interpolationDegree] The new interpolation degree.  If undefined, the existing property will be unchanged.
       */
      SampledPositionProperty.prototype.setInterpolationOptions = function(options) {
          this._property.setInterpolationOptions(options);
      };
  
      /**
       * Adds a new sample.
       *
       * @param {JulianDate} time The sample time.
       * @param {Cartesian3} position The position at the provided time.
       * @param {Cartesian3[]} [derivatives] The array of derivative values at the provided time.
       */
      SampledPositionProperty.prototype.addSample = function(time, position, derivatives) {
          var numberOfDerivatives = this._numberOfDerivatives;
          //>>includeStart('debug', pragmas.debug);
          if (numberOfDerivatives > 0 && (!defined(derivatives) || derivatives.length !== numberOfDerivatives)) {
              throw new DeveloperError('derivatives length must be equal to the number of derivatives.');
          }
          //>>includeEnd('debug');
          this._property.addSample(time, position, derivatives);
      };
  
      /**
       * Adds multiple samples via parallel arrays.
       *
       * @param {JulianDate[]} times An array of JulianDate instances where each index is a sample time.
       * @param {Cartesian3[]} positions An array of Cartesian3 position instances, where each value corresponds to the provided time index.
       * @param {Array[]} [derivatives] An array where each value is another array containing derivatives for the corresponding time index.
       *
       * @exception {DeveloperError} All arrays must be the same length.
       */
      SampledPositionProperty.prototype.addSamples = function(times, positions, derivatives) {
          this._property.addSamples(times, positions, derivatives);
      };
  
      /**
       * 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.
       *
       * @param {Number[]} packedSamples The array of packed samples.
       * @param {JulianDate} [epoch] If any of the dates in packedSamples are numbers, they are considered an offset from this epoch, in seconds.
       */
      SampledPositionProperty.prototype.addSamplesPackedArray = function(packedSamples, epoch) {
          this._property.addSamplesPackedArray(packedSamples, epoch);
      };
  
      /**
       * Removes a sample at the given time, if present.
       *
       * @param {JulianDate} time The sample time.
       * @returns {Boolean} <code>true</code> if a sample at time was removed, <code>false</code> otherwise.
       */
      SampledPositionProperty.prototype.removeSample = function(time) {
          this._property.removeSample(time);
      };
  
      /**
       * Removes all samples for the given time interval.
       *
       * @param {TimeInterval} time The time interval for which to remove all samples.
       */
      SampledPositionProperty.prototype.removeSamples = function(timeInterval) {
          this._property.removeSamples(timeInterval);
      };
  
      /**
       * Compares this property to the provided property and returns
       * <code>true</code> if they are equal, <code>false</code> otherwise.
       *
       * @param {Property} [other] The other property.
       * @returns {Boolean} <code>true</code> if left and right are equal, <code>false</code> otherwise.
       */
      SampledPositionProperty.prototype.equals = function(other) {
          return this === other || //
                 (other instanceof SampledPositionProperty &&
                  Property.equals(this._property, other._property) && //
                  this._referenceFrame === other._referenceFrame);
      };
  export default SampledPositionProperty;
  