void CLASS pseudoinverse (double (*in)[3], double (*out)[3], int size)
{
  double work[3][6], num;
  int i, j, k;

  for (i=0; i < 3; i++) {
    for (j=0; j < 6; j++)
      work[i][j] = j == i+3;
    for (j=0; j < 3; j++)
      for (k=0; k < size; k++)
	work[i][j] += in[k][i] * in[k][j];
  }
  for (i=0; i < 3; i++) {
    num = work[i][i];
    for (j=0; j < 6; j++)
      work[i][j] /= num;
    for (k=0; k < 3; k++) {
      if (k==i) continue;
      num = work[k][i];
      for (j=0; j < 6; j++)
	work[k][j] -= work[i][j] * num;
    }
  }
  for (i=0; i < size; i++)
    for (j=0; j < 3; j++)
      for (out[i][j]=k=0; k < 3; k++)
	out[i][j] += work[j][k+3] * in[i][k];
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.