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# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019.08 #
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# Before run these commands, the files must be properly put.
# python exps/NAS-Bench-201/test-weights.py --base_path $HOME/.torch/NAS-Bench-201-v1_0-e61699
# python exps/NAS-Bench-201/test-weights.py --base_path $HOME/.torch/NAS-Bench-201-v1_1-096897
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import os, sys, time, glob, random, argparse
import numpy as np
import torch
import torch.nn as nn
from pathlib import Path
from tqdm import tqdm
lib_dir = (Path(__file__).parent / '..' / '..' / 'lib').resolve()
if str(lib_dir) not in sys.path: sys.path.insert(0, str(lib_dir))
from procedures import prepare_seed, prepare_logger, save_checkpoint, copy_checkpoint, get_optim_scheduler
from nas_201_api import NASBench201API as API
from log_utils import time_string
from models import get_cell_based_tiny_net
from utils import weight_watcher


def get_cor(A, B):
  return float(np.corrcoef(A, B)[0,1])


def evaluate(api, weight_dir, data: str, use_12epochs_result: bool, valid_or_test: bool):
  norms, accs = [], []
  for idx in tqdm(range(len(api))):
    info = api.get_more_info(idx, data, use_12epochs_result=use_12epochs_result, is_random=False)
    if valid_or_test:
      accs.append(info['valid-accuracy'])
    else:
      accs.append(info['test-accuracy'])
    config = api.get_net_config(idx, data)
    net = get_cell_based_tiny_net(config)
    api.reload(weight_dir, idx)
    params = api.get_net_param(idx, data, None)
    cur_norms = []
    for seed, param in params.items():
      net.load_state_dict(param)
      _, summary = weight_watcher.analyze(net, alphas=False)
      cur_norms.append( summary['lognorm'] )
    norms.append( float(np.mean(cur_norms)) )
    api.clear_params(idx, use_12epochs_result)
  correlation = get_cor(norms, accs)
  print('For {:} with {:} epochs on {:} : the correlation is {:}'.format(data, 12 if use_12epochs_result else 200, 'valid' if valid_or_test else 'test', correlation))


def main(meta_file: str, weight_dir, save_dir):
  api = API(meta_file)
  datasets = ['cifar10-valid', 'cifar10', 'cifar100', 'ImageNet16-120']
  print(time_string() + ' ' + '='*50)
  for data in datasets:
    nums = api.statistics(data, True)
    total = sum([k*v for k, v in nums.items()])
    print('Using 012 epochs, trained on {:20s} : {:} trials in total ({:}).'.format(data, total, nums))
  print(time_string() + ' ' + '='*50)
  for data in datasets:
    nums = api.statistics(data, False)
    total = sum([k*v for k, v in nums.items()])
    print('Using 200 epochs, trained on {:20s} : {:} trials in total ({:}).'.format(data, total, nums))
  print(time_string() + ' ' + '='*50)

  evaluate(api, weight_dir, 'cifar10-valid', False, True)
  
  print('{:} finish this test.'.format(time_string()))


if __name__ == '__main__':
  parser = argparse.ArgumentParser("Analysis of NAS-Bench-201")
  parser.add_argument('--save_dir',   type=str, default='./output/search-cell-nas-bench-201/visuals', help='The base-name of folder to save checkpoints and log.')
  parser.add_argument('--base_path',  type=str, default=None, help='The path to the NAS-Bench-201 benchmark file and weight dir.')
  args = parser.parse_args()

  save_dir = Path(args.save_dir)
  save_dir.mkdir(parents=True, exist_ok=True)
  meta_file = Path(args.base_path + '.pth')
  weight_dir = Path(args.base_path + '-archive')
  assert meta_file.exists(), 'invalid path for api : {:}'.format(meta_file)
  assert weight_dir.exists() and weight_dir.is_dir(), 'invalid path for weight dir : {:}'.format(weight_dir)

  main(str(meta_file), weight_dir, save_dir)