/**
 * Compute 2D affine transformation matrix from three point pairs
 *
 * @param newCoords - Transformed coordinates triad [Coord, Coord, Coord]
 * @param oldCoords - Original coordinates triad [Coord, Coord, Coord]
 *
 * @returns Matrix parameters [a, b, c, d, e, f] for equation:
 *   X = ax + cy + e
 *   Y = bx + dy + f
 *
 * @example
 * ```typescript
 * // Calculate 45-degree rotation matrix
 * const matrix = calcMatrix(
 *   [{x:0,y:0}, {x:0.707,y:0.707}, {x:-0.707,y:0.707}],
 *   [{x:0,y:0}, {x:1,y:0}, {x:0,y:1}]
 * ); // ≈ [0.707, 0.707, -0.707, 0.707, 0, 0]
 * ```
 *
 * @remarks
 * - Points must be non-collinear in both sets
 * - Input order must correspond between sets
 * - Includes safeFactor adjustment for zero values
 */
export declare const calcMatrix: (newCoords: [Coord, Coord, Coord], oldCoords: [Coord, Coord, Coord]) => number[];