r=  4: pre-descent best E 0.7185 (acc 0.004) -> post-descent E 0.6493 acc 0.016
  r=  6: pre-descent best E 0.5638 (acc 0.117) -> post-descent E 0.5333 acc 0.148
  r=  8: pre-descent best E 0.4786 (acc 0.395) -> post-descent E 0.3597 acc 0.750
  r= 10: pre-descent best E 0.6224 (acc 0.180) -> post-descent E 0.5519 acc 0.172
  r= 12: pre-descent best E 0.3977 (acc 0.660) -> post-descent E 0.3396 acc 0.879
  r= 14: pre-descent best E 0.3671 (acc 0.707) -> post-descent E 0.3396 acc 0.836
  r= 16: pre-descent best E 0.6410 (acc 0.145) -> post-descent E 0.5474 acc 0.277