Minor improvements to bloch sphere, see #54

phetsims · Jan 2, 2025 · bc6e5ea · bc6e5ea
1 parent e3d2853
commit bc6e5ea
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Showing 2 changed files with 25 additions and 25 deletions.
diff --git a/js/bloch-sphere/model/BlochSphereModel.ts b/js/bloch-sphere/model/BlochSphereModel.ts
@@ -7,6 +7,7 @@
  * @author Agustín Vallejo (PhET Interactive Simulations)
  */
 
+import Multilink from '../../../../axon/js/Multilink.js';
 import NumberProperty from '../../../../axon/js/NumberProperty.js';
 import Property from '../../../../axon/js/Property.js';
 import TModel from '../../../../joist/js/TModel.js';
@@ -27,9 +28,9 @@ export default class BlochSphereModel implements TModel {
 
   public readonly selectedSceneProperty: Property<BlochSphereScene>;
 
-  public readonly blochSphere: ComplexBlochSphere;
+  public readonly preparationBlochSphere: ComplexBlochSphere;
 
-  // Coefficients of the state equation
+  // Coefficients of the state equation. They are derived from the Bloch Sphere representation on the multilink below.
   // |psi> = upCoefficient |up> + downCoefficient * exp( i * phase * PI ) |down>
   public readonly upCoefficientProperty: NumberProperty;
   public readonly downCoefficientProperty: NumberProperty;
@@ -46,8 +47,8 @@ export default class BlochSphereModel implements TModel {
       phetioValueType: EnumerationIO( BlochSphereScene )
     } );
 
-    this.blochSphere = new ComplexBlochSphere( {
-      tandem: providedOptions.tandem.createTandem( 'blochSphere' )
+    this.preparationBlochSphere = new ComplexBlochSphere( {
+      tandem: providedOptions.tandem.createTandem( 'preparationBlochSphere' )
     } );
 
     this.upCoefficientProperty = new NumberProperty( 1, {
@@ -75,28 +76,27 @@ export default class BlochSphereModel implements TModel {
     this.selectedStateDirectionProperty.link( stateDirection => {
       if ( stateDirection !== StateDirection.CUSTOM ) {
         selectingStateDirection = true;
-        this.blochSphere.polarAngleProperty.value = stateDirection.polarAngle;
-        this.blochSphere.azimuthalAngleProperty.value = stateDirection.azimuthalAngle;
+        this.preparationBlochSphere.polarAngleProperty.value = stateDirection.polarAngle;
+        this.preparationBlochSphere.azimuthalAngleProperty.value = stateDirection.azimuthalAngle;
         selectingStateDirection = false;
       }
     } );
 
-    this.blochSphere.polarAngleProperty.link( theta => {
-      this.upCoefficientProperty.value = Math.cos( theta / 2 );
-      this.downCoefficientProperty.value = Math.sin( theta / 2 );
-
-      if ( !selectingStateDirection ) {
-        this.selectedStateDirectionProperty.value = StateDirection.CUSTOM;
-      }
-    } );
-
-    this.blochSphere.azimuthalAngleProperty.link( phi => {
-      this.phaseFactorProperty.value = phi / Math.PI;
-
-      if ( !selectingStateDirection ) {
-        this.selectedStateDirectionProperty.value = StateDirection.CUSTOM;
+    Multilink.multilink(
+      [
+        this.preparationBlochSphere.polarAngleProperty,
+        this.preparationBlochSphere.azimuthalAngleProperty
+      ],
+      ( polarAngle, azimuthalAngle ) => {
+        this.upCoefficientProperty.value = Math.cos( polarAngle / 2 );
+        this.downCoefficientProperty.value = Math.sin( polarAngle / 2 );
+        this.phaseFactorProperty.value = azimuthalAngle / Math.PI;
+
+        if ( !selectingStateDirection ) {
+          this.selectedStateDirectionProperty.value = StateDirection.CUSTOM;
+        }
       }
-    } );
+    );
   }
 
   /**
@@ -111,7 +111,7 @@ export default class BlochSphereModel implements TModel {
    * @param dt - time step, in seconds
    */
   public step( dt: number ): void {
-    this.blochSphere.step( dt );
+    this.preparationBlochSphere.step( dt );
   }
 }
 

diff --git a/js/bloch-sphere/view/BlochSpherePreparationArea.ts b/js/bloch-sphere/view/BlochSpherePreparationArea.ts
@@ -32,14 +32,14 @@ export default class BlochSpherePreparationArea extends VBox {
 
   public constructor( model: BlochSphereModel, parentNode: Node, providedOptions: BlochSpherePreparationAreaOptions ) {
 
-    const polarSlider = new Slider( model.blochSphere.polarAngleProperty, model.blochSphere.polarAngleProperty.range, {
+    const polarSlider = new Slider( model.preparationBlochSphere.polarAngleProperty, model.preparationBlochSphere.polarAngleProperty.range, {
       center: new Vector2( 100, 200 ),
       tandem: providedOptions.tandem.createTandem( 'polarSlider' ),
       thumbFill: '#444',
       trackSize: new Dimension2( 150, 0.5 ),
       majorTickLength: 10
     } );
-    const azimuthSlider = new Slider( model.blochSphere.azimuthalAngleProperty, model.blochSphere.azimuthalAngleProperty.range, {
+    const azimuthSlider = new Slider( model.preparationBlochSphere.azimuthalAngleProperty, model.preparationBlochSphere.azimuthalAngleProperty.range, {
       center: new Vector2( 100, 100 ),
       tandem: providedOptions.tandem.createTandem( 'azimuthSlider' ),
       thumbFill: '#444',
@@ -80,7 +80,7 @@ export default class BlochSpherePreparationArea extends VBox {
     } );
 
     const blochSphereNode = new BlochSphereNode(
-      model.blochSphere, {
+      model.preparationBlochSphere, {
         tandem: providedOptions.tandem.createTandem( 'blochSphereNode' ),
         expandBounds: false,
         drawTitle: false,