Function eye

utils/array_utils.hpp:250–256

* @brief Populate a square matrix with the identity matrix. * @param a The array to populate. * @param N The number of rows and columns in the square matrix. */

 * @param N The number of rows and columns in the square matrix.
 */
inline void eye(float *a, size_t N) {
  for (size_t i = 0; i < N; i++) {
    for (size_t j = 0; j < N; j++) {
      a[i * N + j] = (i == j) ? 1.0 : 0.0;
    }
  }
}

// Note transformation operations here are purely for testing - they are not
// optimized to be used in hot paths.