@allmaps/transform/dist/transformation-types/Polynomial2.js

Coordinate transformation functions

import { BasePolynomialTransformation } from './BasePolynomialTransformation.js';
/**
 * 2D Second-order Polynomial transformation
 */
export class Polynomial2 extends BasePolynomialTransformation {
    constructor(sourcePoints, destinationPoints) {
        super(sourcePoints, destinationPoints, 2);
    }
    getSourcePointCoefsArray(sourcePoint) {
        return Polynomial2.getPolynomial2SourcePointCoefsArray(sourcePoint);
    }
    /**
     * Get 1x3 coefsArray, populating the Nx3 coefsArrayMatrix
     * 1 x0 y0 x0^2 y0^2 x0*y0
     * ...
     *
     * @param sourcePoint
     */
    static getPolynomial2SourcePointCoefsArray(sourcePoint) {
        return [
            1,
            sourcePoint[0],
            sourcePoint[1],
            sourcePoint[0] ** 2,
            sourcePoint[1] ** 2,
            sourcePoint[0] * sourcePoint[1]
        ];
    }
    // Evaluate the transformation function at a new point
    evaluateFunction(newSourcePoint) {
        if (!this.weightsArrays) {
            this.solve();
        }
        if (!this.weightsArrays) {
            throw new Error('Weights not computed');
        }
        // Apply the helmert coefficients to the input point
        const newDestinationPoint = [0, 0];
        for (let i = 0; i < 2; i++) {
            newDestinationPoint[i] +=
                this.weightsArrays[i][0] +
                    this.weightsArrays[i][1] * newSourcePoint[0] +
                    this.weightsArrays[i][2] * newSourcePoint[1] +
                    this.weightsArrays[i][3] * newSourcePoint[0] ** 2 +
                    this.weightsArrays[i][4] * newSourcePoint[1] ** 2 +
                    this.weightsArrays[i][5] * newSourcePoint[0] * newSourcePoint[1];
        }
        return newDestinationPoint;
    }
    // Evaluate the transformation function's partial derivative to x at a new point
    evaluatePartialDerivativeX(newSourcePoint) {
        if (!this.weightsArrays) {
            this.solve();
        }
        if (!this.weightsArrays) {
            throw new Error('Weights not computed');
        }
        // Apply the helmert coefficients to the input point
        const newDestinationPointPartDerX = [0, 0];
        for (let i = 0; i < 2; i++) {
            newDestinationPointPartDerX[i] +=
                this.weightsArrays[i][1] +
                    2 * this.weightsArrays[i][3] * newSourcePoint[0] +
                    this.weightsArrays[i][5] * newSourcePoint[1];
        }
        return newDestinationPointPartDerX;
    }
    // Evaluate the transformation function's partial derivative to x at a new point
    evaluatePartialDerivativeY(newSourcePoint) {
        if (!this.weightsArrays) {
            this.solve();
        }
        if (!this.weightsArrays) {
            throw new Error('Weights not computed');
        }
        // Apply the helmert coefficients to the input point
        const newDestinationPointPartDerY = [0, 0];
        for (let i = 0; i < 2; i++) {
            newDestinationPointPartDerY[i] +=
                this.weightsArrays[i][2] +
                    2 * this.weightsArrays[i][4] * newSourcePoint[1] +
                    this.weightsArrays[i][5] * newSourcePoint[0];
        }
        return newDestinationPointPartDerY;
    }
}