@thi.ng/matrices/orthagonal.js

Matrix & quaternion operations for 2D/3D geometry processing

import { EPS } from "@thi.ng/math/api";
import { eqDelta } from "@thi.ng/math/eqdelta";
const isOrthagonal = (m, n, eps = EPS) => {
  for (let i = 0; i < n; i++) {
    const ii = i * n;
    for (let j = 0; j < n; j++) {
      const jj = j * n;
      let acc = 0;
      for (let k = 0; k < n; k++) {
        acc += m[ii + k] * m[jj + k];
      }
      if (i == j && !eqDelta(acc, 1, eps) || i != j && !eqDelta(acc, 0, eps)) {
        return false;
      }
    }
  }
  return true;
};
export {
  isOrthagonal
};