JavaScript Histogram Chart

1import {
2    NumericAxis,
3    ZoomPanModifier,
4    ZoomExtentsModifier,
5    MouseWheelZoomModifier,
6    SciChartSurface,
7    ENumericFormat,
8    EAxisAlignment,
9    FastRectangleRenderableSeries,
10    XyxyDataSeries,
11    EColumnYMode,
12    EColumnMode,
13    EDataPointWidthMode,
14    NumberRange,
15    EHorizontalTextPosition,
16    EVerticalTextPosition,
17    ICustomTextureOptions,
18} from "scichart";
19import { appTheme } from "../../../theme";
20
21// Population data by age range
22const populationData = {
23    xValues: [0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100],
24    yValues: {
25        male: [
26            4869936, 5186991, 5175063, 5286053, 5449038, 5752398, 6168124, 6375035, 6265554, 5900833, 6465830, 7108184,
27            6769524, 5676968, 4828153, 3734266, 2732054, 1633630, 587324, 128003, 12023,
28        ],
29        female: [
30            4641147, 4940521, 5010242, 5010526, 5160160, 5501673, 6022599, 6329356, 6299693, 5930345, 6509757, 7178487,
31            7011569, 6157651, 5547296, 4519433, 3704145, 2671974, 1276597, 399148, 60035,
32        ],
33    },
34};
35
36const BREAK_POINTS = [0, 20, 30, 45, 65, 70, 80];
37
38function prepareRectangleData() {
39    const totalData = populationData.xValues.map((xValue, index) => {
40        const total = populationData.yValues.male[index] + populationData.yValues.female[index];
41        return { xValue, yValue: total };
42    });
43
44    // Prepare data for each range
45    const xValues: number[] = [];
46    const yValues: number[] = [];
47    const x1Values: number[] = [];
48    const y1Values: number[] = [];
49
50    BREAK_POINTS.forEach((breakPoint, index) => {
51        let nextBreakPoint = BREAK_POINTS[index + 1];
52
53        if (nextBreakPoint === undefined) {
54            nextBreakPoint = 100; // Set the last range
55        }
56
57        const rangePopulation = totalData
58            .filter((data) => {
59                return data.xValue >= breakPoint && data.xValue < nextBreakPoint;
60            })
61            .reduce((sum, data) => sum + data.yValue, 0);
62
63        xValues.push(breakPoint);
64        yValues.push(rangePopulation);
65        x1Values.push(nextBreakPoint);
66        y1Values.push(0); // Set y1 to 0 for the bottom of the rectangle
67    });
68
69    return { xValues, yValues, x1Values, y1Values };
70}
71
72class StickFigureTextureOptions implements ICustomTextureOptions {
73    options: { stroke: string };
74    textureHeight: number = 48;
75    textureWidth: number = 48;
76    repeat?: boolean = true;
77
78    public constructor(options: { stroke: string; repeat: boolean; textureHeight: number; textureWidth: number }) {
79        this.options = options;
80        this.textureHeight = options.textureHeight;
81        this.textureWidth = options.textureWidth;
82    }
83
84    public createTexture(
85        context: CanvasRenderingContext2D,
86        options: { fill: string; opacity: number; stroke: string }
87    ) {
88        context.fillStyle = options.fill;
89        context.fillRect(0, 0, this.textureWidth, this.textureHeight);
90        context.strokeStyle = options.stroke;
91
92        // Set up transformation: move to center, rotate, move back for
93        context.translate(this.textureWidth / 2, this.textureHeight / 2);
94        context.translate(-this.textureWidth / 2, -this.textureHeight / 2);
95
96        // Proportional values
97        const centerX = this.textureWidth / 2;
98        const headRadius = Math.min(this.textureWidth, this.textureHeight) * 0.16; // 16% of smaller dimension
99        const headY = this.textureHeight * 0.25;
100        const bodyTopY = headY + headRadius;
101        const bodyBottomY = this.textureHeight * 0.63;
102        const armY = bodyTopY + this.textureHeight * 0.06;
103        const armSpan = this.textureWidth * 0.38; // arms reach out 19% each side
104        const legY = bodyBottomY;
105        const legSpan = this.textureWidth * 0.25; // legs out 12.5% each side
106        const legBottomY = this.textureHeight * 0.97;
107
108        // Head
109        context.beginPath();
110        context.arc(centerX, headY, headRadius, 0, Math.PI * 2);
111        context.stroke();
112
113        // Body
114        context.beginPath();
115        context.moveTo(centerX, bodyTopY);
116        context.lineTo(centerX, bodyBottomY);
117        context.stroke();
118
119        // Left Arm
120        context.beginPath();
121        context.moveTo(centerX, armY);
122        context.lineTo(centerX - armSpan, armY + this.textureHeight * 0.09);
123        context.stroke();
124
125        // Right Arm
126        context.beginPath();
127        context.moveTo(centerX, armY);
128        context.lineTo(centerX + armSpan, armY + this.textureHeight * 0.09);
129        context.stroke();
130
131        // Left Leg
132        context.beginPath();
133        context.moveTo(centerX, legY);
134        context.lineTo(centerX - legSpan, legBottomY);
135        context.stroke();
136
137        // Right Leg
138        context.beginPath();
139        context.moveTo(centerX, legY);
140        context.lineTo(centerX + legSpan, legBottomY);
141        context.stroke();
142    }
143}
144
145export const drawExample = async (rootElement: string | HTMLDivElement) => {
146    // Create a SciChartSurface
147    const { sciChartSurface, wasmContext } = await SciChartSurface.create(rootElement, {
148        theme: appTheme.SciChartJsTheme,
149        title: "Europe Population Distribution by Age Range",
150        titleStyle: {
151            fontSize: 24,
152        },
153    });
154
155    // Add X-axis
156    const xAxis = new NumericAxis(wasmContext, {
157        axisTitle: "Age Range (Years)",
158        autoTicks: false,
159        majorDelta: 5,
160        drawMajorBands: false,
161        drawMinorGridLines: false,
162        drawMajorTickLines: false,
163        drawMinorTickLines: false,
164        axisTitleStyle: {
165            fontSize: 13,
166            fontFamily: "Arial",
167            color: "#ffffff",
168            fontStyle: "italic",
169        },
170        growBy: new NumberRange(0.02, 0.02),
171    });
172    xAxis.labelProvider.formatLabel = (value: number) => {
173        // Custom label formatter to improve readability
174        if (BREAK_POINTS.includes(value)) {
175            return value.toString();
176        }
177        if (value === 100) {
178            return "100+";
179        }
180        return null;
181    };
182    sciChartSurface.xAxes.add(xAxis);
183
184    // Add Y-axis
185    const yAxis = new NumericAxis(wasmContext, {
186        axisTitle: "Population (Millions)",
187        labelFormat: ENumericFormat.Engineering,
188        axisAlignment: EAxisAlignment.Left,
189        drawMajorBands: false,
190        drawMinorGridLines: false,
191        drawMajorGridLines: true,
192        drawMajorTickLines: false,
193        drawMinorTickLines: false,
194        axisTitleStyle: {
195            fontSize: 14,
196            fontFamily: "Arial",
197            color: "#ffffff",
198            fontStyle: "italic",
199        },
200        growBy: new NumberRange(0.01, 0.1),
201    });
202    sciChartSurface.yAxes.add(yAxis);
203
204    // Prepare data and create rectangle series
205    const { xValues, yValues, x1Values, y1Values } = prepareRectangleData();
206
207    const rectangleSeries = new FastRectangleRenderableSeries(wasmContext, {
208        dataSeries: new XyxyDataSeries(wasmContext, {
209            xValues,
210            yValues,
211            x1Values,
212            y1Values,
213        }),
214        columnXMode: EColumnMode.StartEnd,
215        columnYMode: EColumnYMode.TopBottom,
216        dataPointWidthMode: EDataPointWidthMode.Range,
217        stroke: appTheme.DarkIndigo,
218        opacity: 0.8,
219        fill: appTheme.MutedSkyBlue,
220        topCornerRadius: 8,
221        bottomCornerRadius: 0,
222        customTextureOptions: new StickFigureTextureOptions({
223            stroke: appTheme.MutedBlue,
224            repeat: true,
225            textureWidth: 40,
226            textureHeight: 40,
227        }),
228        dataLabels: {
229            color: appTheme.DarkIndigo,
230            style: {
231                fontSize: 16,
232            },
233            precision: 0,
234            numericFormat: ENumericFormat.Engineering,
235            verticalTextPosition: EVerticalTextPosition.Above,
236            horizontalTextPosition: EHorizontalTextPosition.Right,
237        },
238    });
239    sciChartSurface.renderableSeries.add(rectangleSeries);
240
241    // Adjust the size of the custom texture so it scales as you zoom
242    sciChartSurface.layoutMeasured.subscribe((data) => {
243        const width = xAxis.getCurrentCoordinateCalculator().getCoordWidth(5);
244        const height = yAxis.getCurrentCoordinateCalculator().getCoordWidth(10000000);
245        if (
246            width !== rectangleSeries.customTextureOptions.textureWidth ||
247            height !== rectangleSeries.customTextureOptions.textureHeight
248        ) {
249            rectangleSeries.customTextureOptions = new StickFigureTextureOptions({
250                stroke: appTheme.MutedBlue,
251                repeat: true,
252                textureWidth: width,
253                textureHeight: height,
254            });
255        }
256    });
257
258    // Add interactivity modifiers
259    sciChartSurface.chartModifiers.add(new ZoomPanModifier(), new ZoomExtentsModifier(), new MouseWheelZoomModifier());
260
261    return { sciChartSurface, wasmContext };
262};
263