node-red-contrib-tak-registration
Version:
A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK
87 lines • 3.39 kB
JavaScript
// index.ts
import { coordAll, featureEach } from "@turf/meta";
import { getCoords } from "@turf/invariant";
import { featureCollection, isObject, isNumber } from "@turf/helpers";
import { centerMean } from "@turf/center-mean";
import { pointsWithinPolygon } from "@turf/points-within-polygon";
import { ellipse } from "@turf/ellipse";
function standardDeviationalEllipse(points, options) {
var _a;
options = options || {};
if (!isObject(options)) throw new Error("options is invalid");
const steps = options.steps || 64;
const weightTerm = options.weight;
const properties = options.properties || {};
if (!isNumber(steps)) throw new Error("steps must be a number");
if (!isObject(properties)) throw new Error("properties must be a number");
const numberOfFeatures = coordAll(points).length;
const meanCenter = centerMean(points, { weight: weightTerm });
let xDeviationSquaredSum = 0;
let yDeviationSquaredSum = 0;
let xyDeviationSum = 0;
featureEach(points, function(point) {
var _a2;
const weight = weightTerm ? ((_a2 = point.properties) == null ? void 0 : _a2[weightTerm]) || 1 : 1;
const deviation = getDeviations(getCoords(point), getCoords(meanCenter));
xDeviationSquaredSum += Math.pow(deviation.x, 2) * weight;
yDeviationSquaredSum += Math.pow(deviation.y, 2) * weight;
xyDeviationSum += deviation.x * deviation.y * weight;
});
const bigA = xDeviationSquaredSum - yDeviationSquaredSum;
const bigB = Math.sqrt(Math.pow(bigA, 2) + 4 * Math.pow(xyDeviationSum, 2));
const bigC = 2 * xyDeviationSum;
const theta = Math.atan((bigA + bigB) / bigC);
const thetaDeg = theta * 180 / Math.PI;
let sigmaXsum = 0;
let sigmaYsum = 0;
let weightsum = 0;
featureEach(points, function(point) {
var _a2;
const weight = weightTerm ? ((_a2 = point.properties) == null ? void 0 : _a2[weightTerm]) || 1 : 1;
const deviation = getDeviations(getCoords(point), getCoords(meanCenter));
sigmaXsum += Math.pow(
deviation.x * Math.cos(theta) - deviation.y * Math.sin(theta),
2
) * weight;
sigmaYsum += Math.pow(
deviation.x * Math.sin(theta) + deviation.y * Math.cos(theta),
2
) * weight;
weightsum += weight;
});
const sigmaX = Math.sqrt(2 * sigmaXsum / weightsum);
const sigmaY = Math.sqrt(2 * sigmaYsum / weightsum);
const theEllipse = ellipse(meanCenter, sigmaX, sigmaY, {
units: "degrees",
angle: thetaDeg,
steps,
properties
});
const pointsWithinEllipse = pointsWithinPolygon(
points,
featureCollection([theEllipse])
);
const standardDeviationalEllipseProperties = {
meanCenterCoordinates: getCoords(meanCenter),
semiMajorAxis: sigmaX,
semiMinorAxis: sigmaY,
numberOfFeatures,
angle: thetaDeg,
percentageWithinEllipse: 100 * coordAll(pointsWithinEllipse).length / numberOfFeatures
};
theEllipse.properties = (_a = theEllipse.properties) != null ? _a : {};
theEllipse.properties.standardDeviationalEllipse = standardDeviationalEllipseProperties;
return theEllipse;
}
function getDeviations(coordinates, center) {
return {
x: coordinates[0] - center[0],
y: coordinates[1] - center[1]
};
}
var turf_standard_deviational_ellipse_default = standardDeviationalEllipse;
export {
turf_standard_deviational_ellipse_default as default,
standardDeviationalEllipse
};
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