JavaScript Polar Ultrasound Heatmap

1import {
2    PolarMouseWheelZoomModifier,
3    PolarZoomExtentsModifier,
4    PolarPanModifier,
5    PolarNumericAxis,
6    SciChartPolarSurface,
7    EPolarAxisMode, 
8    EAxisAlignment, 
9    Thickness,
10    HeatmapColorMap,
11    UniformHeatmapDataSeries,
12    PolarUniformHeatmapRenderableSeries,
13    LineArrowAnnotation,
14    EArrowHeadPosition,
15    ELegendPlacement,
16    ELabelPlacement
17} from "scichart";
18import { appTheme } from "../../../theme";
19
20const FETAL_DATA_PATH = "heatmap_data.csv";
21
22async function parseCSV(): Promise<number[][]> {
23    const fileData = await fetch(FETAL_DATA_PATH);
24    const rows = (await fileData.text()).split("\n");
25
26    const zValues = rows.map(row => {
27        return row.split(",")
28            // from base 16 to decimal value
29            .map(value => parseInt(value, 16))
30    });
31
32    return zValues;
33}
34
35export const drawExample = async (rootElement: string | HTMLDivElement) => {
36    const { sciChartSurface, wasmContext } = await SciChartPolarSurface.create(rootElement, {
37        theme: appTheme.SciChartJsTheme,
38        title: "Fetal ultrasound at 31 weeks",
39        titleStyle: {
40            fontSize: 32
41        }
42    });
43
44    const angularAxisX = new PolarNumericAxis(wasmContext, {
45        polarAxisMode: EPolarAxisMode.Angular,
46        axisAlignment: EAxisAlignment.Top,
47        useNativeText: false,
48        labelPrecision: 0,
49        drawMajorBands: false,
50        drawMajorGridLines: false,
51        drawMinorGridLines: false,
52        totalAngle: Math.PI / 3,
53        startAngle: (Math.PI * 3 / 2) - (Math.PI / 6), 
54        // (start at 270deg) - (half of totalAngle) = 240deg
55        // could be simplified to `Math.PI * 4 / 3`
56    });
57    sciChartSurface.xAxes.add(angularAxisX);
58
59    const radialAxisY = new PolarNumericAxis(wasmContext, {
60        polarAxisMode: EPolarAxisMode.Radial,
61        axisAlignment: EAxisAlignment.Left,
62        useNativeText: false,
63        labelPrecision: 0,
64        drawMajorBands: false,
65        drawMajorGridLines: false,
66        drawMinorGridLines: false,
67        innerRadius: 0.4,
68        startAngle: Math.PI * 3 / 2 - Math.PI / 6, 
69    });
70    sciChartSurface.yAxes.add(radialAxisY);
71
72    // Heatmap
73    const heatmapSeries = new PolarUniformHeatmapRenderableSeries(wasmContext, {
74        opacity: 0.8,
75        dataSeries: new UniformHeatmapDataSeries(wasmContext, {
76            xStart: 0,
77            xStep: 1,
78            yStart: 0,
79            yStep: 1,
80            zValues: await parseCSV()
81        }),
82        colorMap: new HeatmapColorMap({
83            minimum: 0,
84            maximum: 255,
85            gradientStops: [
86                { offset: 0, color: "transparent" },
87                { offset: 1, color: "white" }
88            ]
89        })
90    });
91    sciChartSurface.renderableSeries.add(heatmapSeries);
92
93    // Optional Annotations
94    const headLine = new LineArrowAnnotation({
95        x1: 165.9,
96        y1: 74.5,
97        x2: 219.2,
98        y2: 136.5,
99        stroke: "white",
100        strokeThickness: 2,
101        arrowHeadPosition: EArrowHeadPosition.StartEnd,
102        arrowStyle: {
103            headWidth: 18,
104            headLength: 14
105        },
106        isEditable: true,
107        // strokeDashArray: [6, 30],
108        // labelValue: "Head diameter",
109        // axisLabelFill: appTheme.VividTeal,
110        // labelPlacement: ELabelPlacement.Auto,
111    });
112    const femurLine = new LineArrowAnnotation({
113        x1: 61, 
114        y1: 166,
115        x2: 82,
116        y2: 127,
117        stroke: "white",
118        strokeThickness: 2,
119        arrowHeadPosition: EArrowHeadPosition.StartEnd,
120        arrowStyle: {
121            headWidth: 10
122        },
123        // strokeDashArray: [6, 30],
124        // labelValue: "Head diameter",
125        // axisLabelFill: appTheme.VividTeal,
126        // labelPlacement: ELabelPlacement.Auto,
127    });
128    sciChartSurface.annotations.add(
129        headLine, 
130        femurLine
131    );
132
133    sciChartSurface.chartModifiers.add(
134        new PolarMouseWheelZoomModifier(),
135        new PolarZoomExtentsModifier(),
136        new PolarPanModifier()
137    );
138
139    return { sciChartSurface, wasmContext };
140};