diff --git a/exps/algos/BOHB.py b/exps/algos/BOHB.py
index 5398f79..35532c2 100644
--- a/exps/algos/BOHB.py
+++ b/exps/algos/BOHB.py
@@ -5,18 +5,15 @@
 # required to install hpbandster ##################################
 # bash ./scripts-search/algos/BOHB.sh -1         ##################
 ###################################################################
-import os, sys, time, glob, random, argparse
-import numpy as np, collections
+import os, sys, time, random, argparse
 from copy import deepcopy
 from pathlib import Path
 import torch
-import torch.nn as nn
 lib_dir = (Path(__file__).parent / '..' / '..' / 'lib').resolve()
 if str(lib_dir) not in sys.path: sys.path.insert(0, str(lib_dir))
-from config_utils import load_config, dict2config, configure2str
+from config_utils import load_config
 from datasets     import get_datasets, SearchDataset
-from procedures   import prepare_seed, prepare_logger, save_checkpoint, copy_checkpoint, get_optim_scheduler
-from utils        import get_model_infos, obtain_accuracy
+from procedures   import prepare_seed, prepare_logger
 from log_utils    import AverageMeter, time_string, convert_secs2time
 from nas_201_api  import NASBench201API as API
 from models       import CellStructure, get_search_spaces
diff --git a/exps/algos/DARTS-V1.py b/exps/algos/DARTS-V1.py
index e033884..32f4b6b 100644
--- a/exps/algos/DARTS-V1.py
+++ b/exps/algos/DARTS-V1.py
@@ -3,11 +3,9 @@
 ########################################################
 # DARTS: Differentiable Architecture Search, ICLR 2019 #
 ########################################################
-import os, sys, time, glob, random, argparse
-import numpy as np
+import sys, time, random, argparse
 from copy import deepcopy
 import torch
-import torch.nn as nn
 from pathlib import Path
 lib_dir = (Path(__file__).parent / '..' / '..' / 'lib').resolve()
 if str(lib_dir) not in sys.path: sys.path.insert(0, str(lib_dir))
diff --git a/exps/experimental/test-ww.py b/exps/experimental/test-ww.py
new file mode 100644
index 0000000..5d2813f
--- /dev/null
+++ b/exps/experimental/test-ww.py
@@ -0,0 +1,21 @@
+import sys, time, random, argparse
+from copy import deepcopy
+import torchvision.models as models
+from pathlib import Path
+lib_dir = (Path(__file__).parent / '..' / '..' / 'lib').resolve()
+if str(lib_dir) not in sys.path: sys.path.insert(0, str(lib_dir))
+
+from utils import weight_watcher
+
+
+def main():
+  model = models.vgg19_bn(pretrained=True)
+  _, summary = weight_watcher.analyze(model, alphas=False)
+  # print(summary)
+  for key, value in summary.items():
+    print('{:10s} : {:}'.format(key, value))
+  # import pdb; pdb.set_trace()
+
+
+if __name__ == '__main__':
+  main()
\ No newline at end of file
diff --git a/lib/utils/nas_utils.py b/lib/utils/nas_utils.py
index bcab05e..c701935 100644
--- a/lib/utils/nas_utils.py
+++ b/lib/utils/nas_utils.py
@@ -1,11 +1,10 @@
 # This file is for experimental usage
-import os, sys, torch, random
+import torch, random
 import numpy as np
 from copy import deepcopy
-from tqdm import tqdm
 import torch.nn as nn
 
-from utils  import obtain_accuracy
+# from utils  import obtain_accuracy
 from models import CellStructure
 from log_utils import time_string
 
diff --git a/lib/utils/weight_watcher.py b/lib/utils/weight_watcher.py
new file mode 100644
index 0000000..f675c72
--- /dev/null
+++ b/lib/utils/weight_watcher.py
@@ -0,0 +1,319 @@
+#####################################################
+# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2020.03 #
+#####################################################
+# Reformulate the codes in https://github.com/CalculatedContent/WeightWatcher
+#####################################################
+import numpy as np
+from typing import List
+import torch.nn as nn
+from collections import OrderedDict
+from sklearn.decomposition import TruncatedSVD
+
+
+def available_module_types():
+  return (nn.Conv2d, nn.Linear)
+
+
+def get_conv2D_Wmats(tensor: np.ndarray) -> List[np.ndarray]:
+  """
+  Extract W slices from a 4 index conv2D tensor of shape: (N,M,i,j) or (M,N,i,j).
+  Return ij (N x M) matrices
+  """
+  mats = []
+  N, M, imax, jmax = tensor.shape
+  assert N + M >= imax + jmax, 'invalid tensor shape detected: {}x{} (NxM), {}x{} (i,j)'.format(N, M, imax, jmax)
+  for i in range(imax):
+    for j in range(jmax):
+      w = tensor[:, :, i, j]
+      if N < M: w = w.T
+      mats.append(w)
+  return mats
+
+
+def glorot_norm_check(W, N, M, rf_size, lower=0.5, upper=1.5):
+  """Check if this layer needs Glorot Normalization Fix"""
+
+  kappa = np.sqrt(2 / ((N + M) * rf_size))
+  norm = np.linalg.norm(W)
+
+  check1 = norm / np.sqrt(N * M)
+  check2 = norm / (kappa * np.sqrt(N * M))
+
+  if (rf_size > 1) and (check2 > lower) and (check2 < upper):
+    return check2, True
+  elif (check1 > lower) & (check1 < upper):
+    return check1, True
+  else:
+    if rf_size > 1: return check2, False
+    else: return check1, False
+
+def glorot_norm_fix(w, n, m, rf_size):
+  """Apply Glorot Normalization Fix."""
+  kappa = np.sqrt(2 / ((n + m) * rf_size))
+  w = w / kappa
+  return w
+
+
+def analyze_weights(weights, min_size, max_size, alphas, lognorms, spectralnorms, softranks, normalize, glorot_fix):
+  results = OrderedDict()
+  count = len(weights)
+  if count == 0: return results
+
+  for i, weight in enumerate(weights):
+    M, N = np.min(weight.shape), np.max(weight.shape)
+    Q = N / M
+    results[i] = cur_res = OrderedDict(N=N, M=M, Q=Q)
+    check, checkTF = glorot_norm_check(weight, N, M, count)
+    cur_res['check'] = check
+    cur_res['checkTF'] = checkTF
+    # assume receptive field size is count
+    if glorot_fix:
+      weight = glorot_norm_fix(weight, N, M, count)
+    else:
+      # probably never needed since we always fix for glorot
+      weight = weight * np.sqrt(count / 2.0)
+
+    if spectralnorms:  # spectralnorm is the max eigenvalues
+      svd = TruncatedSVD(n_components=1, n_iter=7, random_state=10)
+      svd.fit(weight)
+      sv = svd.singular_values_
+      sv_max = np.max(sv)
+      if normalize:
+        evals = sv * sv / N
+      else:
+        evals = sv * sv
+      lambda0 = evals[0]
+      cur_res["spectralnorm"] = lambda0
+      cur_res["logspectralnorm"] = np.log10(lambda0)
+    else:
+      lambda0 = None
+
+    if M < min_size:
+      summary = "Weight matrix {}/{} ({},{}): Skipping: too small (<{})".format(i + 1, count, M, N, min_size)
+      cur_res["summary"] = summary
+      continue
+    elif max_size > 0 and M > max_size:
+      summary = "Weight matrix {}/{} ({},{}): Skipping: too big (testing) (>{})".format(i + 1, count, M, N, max_size)
+      cur_res["summary"] = summary
+      continue
+    else:
+      summary = []
+    if alphas:
+      import powerlaw
+      svd = TruncatedSVD(n_components=M - 1, n_iter=7, random_state=10)
+      svd.fit(weight.astype(float))
+      sv = svd.singular_values_
+      if normalize: evals = sv * sv / N
+      else: evals = sv * sv
+
+      lambda_max = np.max(evals)
+      fit = powerlaw.Fit(evals, xmax=lambda_max, verbose=False)
+      alpha = fit.alpha
+      cur_res["alpha"] = alpha
+      D = fit.D
+      cur_res["D"] = D
+      cur_res["lambda_min"] = np.min(evals)
+      cur_res["lambda_max"] = lambda_max
+      alpha_weighted = alpha * np.log10(lambda_max)
+      cur_res["alpha_weighted"] = alpha_weighted
+      tolerance = lambda_max * M * np.finfo(np.max(sv)).eps
+      cur_res["rank_loss"] = np.count_nonzero(sv > tolerance, axis=-1)
+
+      logpnorm = np.log10(np.sum([ev ** alpha for ev in evals]))
+      cur_res["logpnorm"] = logpnorm
+
+      summary.append(
+        "Weight matrix {}/{} ({},{}): Alpha: {}, Alpha Weighted: {}, D: {}, pNorm {}".format(i + 1, count, M, N, alpha,
+                                                                                             alpha_weighted, D,
+                                                                                             logpnorm))
+
+    if lognorms:
+      norm = np.linalg.norm(weight)  # Frobenius Norm
+      cur_res["norm"] = norm
+      lognorm = np.log10(norm)
+      cur_res["lognorm"] = lognorm
+
+      X = np.dot(weight.T, weight)
+      if normalize: X = X / N
+      normX = np.linalg.norm(X)  # Frobenius Norm
+      cur_res["normX"] = normX
+      lognormX = np.log10(normX)
+      cur_res["lognormX"] = lognormX
+
+      summary.append(
+        "Weight matrix {}/{} ({},{}): LogNorm: {} ; LogNormX: {}".format(i + 1, count, M, N, lognorm, lognormX))
+
+      if softranks:
+        softrank = norm ** 2 / sv_max ** 2
+        softranklog = np.log10(softrank)
+        softranklogratio = lognorm / np.log10(sv_max)
+        cur_res["softrank"] = softrank
+        cur_res["softranklog"] = softranklog
+        cur_res["softranklogratio"] = softranklogratio
+        summary += "{}. Softrank: {}. Softrank log: {}. Softrank log ratio: {}".format(summary, softrank, softranklog,
+                                                                                       softranklogratio)
+    cur_res["summary"] = "\n".join(summary)
+  return results
+
+
+def compute_details(results):
+  """
+  Return a pandas data frame.
+  """
+  final_summary = OrderedDict()
+
+  metrics = {
+    # key in "results" : pretty print name
+    "check": "Check",
+    "checkTF": "CheckTF",
+    "norm": "Norm",
+    "lognorm": "LogNorm",
+    "normX": "Norm X",
+    "lognormX": "LogNorm X",
+    "alpha": "Alpha",
+    "alpha_weighted": "Alpha Weighted",
+    "spectralnorm": "Spectral Norm",
+    "logspectralnorm": "Log Spectral Norm",
+    "softrank": "Softrank",
+    "softranklog": "Softrank Log",
+    "softranklogratio": "Softrank Log Ratio",
+    "sigma_mp": "Marchenko-Pastur (MP) fit sigma",
+    "numofSpikes": "Number of spikes per MP fit",
+    "ratio_numofSpikes": "aka, percent_mass, Number of spikes / total number of evals",
+    "softrank_mp": "Softrank for MP fit",
+    "logpnorm": "alpha pNorm"
+  }
+
+  metrics_stats = []
+  for metric in metrics:
+    metrics_stats.append("{}_min".format(metric))
+    metrics_stats.append("{}_max".format(metric))
+    metrics_stats.append("{}_avg".format(metric))
+
+    metrics_stats.append("{}_compound_min".format(metric))
+    metrics_stats.append("{}_compound_max".format(metric))
+    metrics_stats.append("{}_compound_avg".format(metric))
+
+  columns = ["layer_id", "layer_type", "N", "M", "layer_count", "slice",
+             "slice_count", "level", "comment"] + [*metrics] + metrics_stats
+
+  metrics_values = {}
+  metrics_values_compound = {}
+
+  for metric in metrics:
+    metrics_values[metric] = []
+    metrics_values_compound[metric] = []
+
+  layer_count = 0
+  for layer_id, result in results.items():
+    layer_count += 1
+
+    layer_type = np.NAN
+    if "layer_type" in result:
+      layer_type = str(result["layer_type"]).replace("LAYER_TYPE.", "")
+
+    compounds = {}  # temp var
+    for metric in metrics:
+      compounds[metric] = []
+
+    slice_count, Ntotal, Mtotal = 0, 0, 0
+    for slice_id, summary in result.items():
+      if not str(slice_id).isdigit():
+        continue
+      slice_count += 1
+
+      N = np.NAN
+      if "N" in summary:
+        N = summary["N"]
+        Ntotal += N
+
+      M = np.NAN
+      if "M" in summary:
+        M = summary["M"]
+        Mtotal += M
+
+      data = {"layer_id": layer_id, "layer_type": layer_type, "N": N, "M": M, "slice": slice_id, "level": "SLICE",
+              "comment": "Slice level"}
+      for metric in metrics:
+        if metric in summary:
+          value = summary[metric]
+          if value is not None:
+            metrics_values[metric].append(value)
+            compounds[metric].append(value)
+            data[metric] = value
+
+    data = {"layer_id": layer_id, "layer_type": layer_type, "N": Ntotal, "M": Mtotal, "slice_count": slice_count,
+            "level": "LAYER", "comment": "Layer level"}
+    # Compute the compound value over the slices
+    for metric, value in compounds.items():
+      count = len(value)
+      if count == 0:
+        continue
+
+      compound = np.mean(value)
+      metrics_values_compound[metric].append(compound)
+      data[metric] = compound
+
+  data = {"layer_count": layer_count, "level": "NETWORK", "comment": "Network Level"}
+  for metric, metric_name in metrics.items():
+    if metric not in metrics_values or len(metrics_values[metric]) == 0:
+      continue
+
+    values = metrics_values[metric]
+    minimum = min(values)
+    maximum = max(values)
+    avg = np.mean(values)
+    final_summary[metric] = avg
+    # print("{}: min: {}, max: {}, avg: {}".format(metric_name, minimum, maximum, avg))
+    data["{}_min".format(metric)] = minimum
+    data["{}_max".format(metric)] = maximum
+    data["{}_avg".format(metric)] = avg
+
+    values = metrics_values_compound[metric]
+    minimum = min(values)
+    maximum = max(values)
+    avg = np.mean(values)
+    final_summary["{}_compound".format(metric)] = avg
+    # print("{} compound: min: {}, max: {}, avg: {}".format(metric_name, minimum, maximum, avg))
+    data["{}_compound_min".format(metric)] = minimum
+    data["{}_compound_max".format(metric)] = maximum
+    data["{}_compound_avg".format(metric)] = avg
+
+  return final_summary
+
+
+def analyze(model: nn.Module, min_size=50, max_size=0,
+            alphas: bool = False, lognorms: bool = True, spectralnorms: bool = False,
+            softranks: bool = False, normalize: bool = False, glorot_fix: bool = False):
+  """
+  Analyze the weight matrices of a model.
+  :param model: A PyTorch model
+  :param min_size: The minimum weight matrix size to analyze.
+  :param max_size: The maximum weight matrix size to analyze (0 = no limit).
+  :param alphas: Compute the power laws (alpha) of the weight matrices.
+    Time consuming so disabled by default (use lognorm if you want speed)
+  :param lognorms: Compute the log norms of the weight matrices.
+  :param spectralnorms: Compute the spectral norm (max eigenvalue) of the weight matrices.
+  :param softranks: Compute the soft norm (i.e. StableRank) of the weight matrices.
+  :param normalize: Normalize or not.
+  :param glorot_fix:
+  :return: (a dict of all layers' results, a dict of the summarized info)
+  """
+  names, modules = [], []
+  for name, module in model.named_modules():
+    if isinstance(module, available_module_types()):
+      names.append(name)
+      modules.append(module)
+  print('There are {:} layers to be analyzed in this model.'.format(len(modules)))
+  all_results = OrderedDict()
+  for index, module in enumerate(modules):
+    if isinstance(module, nn.Linear):
+      weights = [module.weight.cpu().detach().numpy()]
+    else:
+      weights = get_conv2D_Wmats(module.weight.cpu().detach().numpy())
+    results = analyze_weights(weights, min_size, max_size, alphas, lognorms, spectralnorms, softranks, normalize, glorot_fix)
+    results['id'] = index
+    results['type'] = type(module)
+    all_results[index] = results
+  summary = compute_details(all_results)
+  return all_results, summary
\ No newline at end of file