calculating q value

src/calculations/qvalue.ts

@@ -0,0 +1,30 @@
+import { Beamstop } from "../utils/types";
+import { Ray } from "./ray";
+import { Vector2 } from "three";
+
+export const calculateQValue = (distance: number, cameraLength: number, wavelength: number): number | null => {
+    if (cameraLength === 0 || wavelength == 0) {
+        return null;
+    }
+    if (cameraLength < 0 || distance < 0 || wavelength < 0) {
+        return null;
+    }
+    return 4 * Math.PI * Math.sin(Math.atan(distance / cameraLength) / 2) / wavelength;
+};
+
+export const calculateDistanceFromQValue = (qValue: number, cameraLength: number, wavelength: number): number | null => {
+    if (qValue < 0 || cameraLength < 0 || wavelength < 0) {
+        return null;
+    }
+    const temp = wavelength * qValue / (4 * Math.PI);
+
+    if (Math.abs(temp) >= Math.sqrt(2) / 2) {
+        return null;
+    }
+    return Math.tan(2 * Math.asin(temp)) * cameraLength;
+};
+
+export const getPointForQ = (qValue: number, angle: number, cameralength: number, wavelength: number, beamstop: Beamstop): Vector2 => {
+    const ray = new Ray(new Vector2(Math.cos(angle), Math.sin(angle)), new Vector2(beamstop.centre.x ?? 0, beamstop.centre.y ?? 0));
+    return ray.getPointAtDistance(1.0e3 * (calculateDistanceFromQValue(qValue, cameralength, wavelength) ?? 0));
+};

src/calculations/ray.ts

@@ -13,11 +13,6 @@ export class Ray {
     this.initial_point = initial_point;
   }
 
-  /**
-   * Returns a point in the ray
-   * @param scalar
-   * @returns
-   */
   getPoint(scalar: number): Vector2 {
     const result = new Vector2(this.direction.x, this.direction.y);
     result.multiplyScalar(scalar);
@@ -56,8 +51,8 @@ export class Ray {
     const b =
       2 * coeffOfx2 * this.direction.x * this.initial_point.x +
       coeffOfxy *
-        (this.direction.x * this.initial_point.y +
-          this.direction.y * this.initial_point.x) +
+      (this.direction.x * this.initial_point.y +
+        this.direction.y * this.initial_point.x) +
       2 * coeffOfy2 * this.direction.y * this.initial_point.y +
       coeffOfx * this.direction.x +
       coeffOfy * this.direction.y;

src/plot/centrePlot.tsx

@@ -31,6 +31,7 @@ export default function CentrePlot(): JSX.Element {
     }
     return state.current;
   });
+
   const beamstop = useBeamstopStore((state): Beamstop => {
     if (plotConfig.plotAxes === PlotAxes.milimeter) {
       return {
@@ -65,7 +66,6 @@ export default function CentrePlot(): JSX.Element {
     };
   });
 
-  //unit miss alignment
   const domains = getDomains(detector, cameraTube);
 
   return (