enhanced graph shifting

src/app/services/math.service.ts

@@ -0,0 +1,122 @@
+/**
+ * Copyright (C) 2018 Michael Czechowski <mail@dailysh.it>
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+import { Inject, Injectable } from '@angular/core';
+import * as Selection from 'd3-selection';
+import * as Random from 'd3-random';
+
+import { Point } from './../models/point.model';
+import { Graph } from './../models/graph.model';
+
+@Injectable()
+export class MathService {
+
+  /**
+   * Calculate distance between to points with coordinates.
+   * @param a
+   * @param b
+   */
+  public Δ(a: Point, b: Point) {
+    return Math.pow(Math.pow(a.x - b.x, 2) + Math.pow(a.y - b.y, 2), 0.5);
+  }
+
+  public getClosestCenter(point: Point, matrix: any) {
+    if (this.Δ(point, matrix.start) < this.Δ(point, matrix.end)) {
+      return matrix.start;
+    } else {
+      return matrix.end;
+    }
+  }
+
+  public getFarestCenter(point: Point, matrix: any) {
+    if (this.Δ(point, matrix.start) > this.Δ(point, matrix.end)) {
+      return matrix.start;
+    } else {
+      return matrix.end;
+    }
+  }
+
+  public randomPoint(matrix: any, overlap: number) {
+    const x = {
+      min: matrix.center.x - matrix.width * overlap,
+      max: matrix.center.x + matrix.width * overlap
+    };
+    const y = {
+      min: matrix.center.y - matrix.height * overlap,
+      max: matrix.center.y + matrix.height * overlap
+    };
+
+    return {
+      x: Random.randomUniform(x.min, x.max)(),
+      y: Random.randomUniform(y.min, y.max)()
+    };
+  }
+
+  public centerOfArea(width, height): Point {
+    return {
+      x: width * 0.5,
+      y: height * 0.5
+    };
+  }
+
+  public centerOfPoints(p1: Point, p2: Point) {
+    return {
+      x: (p1.x + p2.x) * 0.5,
+      y: (p1.y + p2.y) * 0.5
+    };
+  }
+
+  public centerOfCurve(curve: Point[]) {
+    const genMedian = this.medianPoint(curve);
+    const p1 = genMedian.next().value;
+    const p2 = genMedian.next().value;
+    const radians = this.angleRadians(p1, p2);
+
+    return Object.assign(this.centerOfPoints(p1, p2), { ascent: radians });
+  }
+
+  public angleRadians(p1: Point, p2: Point) {
+    return Math.atan2(p2.y - p1.y, p2.x - p1.x);
+  }
+
+  public angleDegree(p1: Point, p2: Point) {
+    return this.angleRadians(p1, p2) * 180 / Math.PI;
+  }
+
+  public medianIndex(list: any): number {
+    return Math.floor(list.length * 0.5);
+  }
+
+  public *medianPoint(points: Point[]) {
+    let index: number;
+    const list: Point[] = points.slice();
+
+    while (list) {
+      index = this.medianIndex(points);
+      yield list[index];
+
+      list.splice(index, 1);
+    }
+  }
+
+  public *flipSign() {
+    let sign = 1;
+
+    while (true) {
+      yield sign = sign * (-1);
+    }
+  }
+}