批量处理TXT文件:使用eval进行矩阵数据提取

版权申诉
0 下载量 100 浏览量 更新于2024-10-14 收藏 1KB RAR 举报
本资源包旨在演示如何使用eval函数在MATLAB环境中批量读取存储在多个TXT文件中的数据,并通过批量处理实现简单矩阵的提取。在进行批量读取和处理之前,通常需要编写代码来迭代访问每个文件,然后利用MATLAB的eval函数动态地处理文件中的数据。eval函数在MATLAB编程中具有强大的功能,可以执行字符串形式的MATLAB命令或表达式,这对于需要动态编程的应用场景非常有用。但是,由于eval函数的灵活性可能导致安全风险,应当谨慎使用,并确保传入的字符串内容是可控的,避免潜在的代码注入攻击。以下是实现批量读取TXT文件并提取矩阵数据的步骤: 1. 首先,确定需要处理的TXT文件存储路径,并使用MATLAB的文件操作函数(如dir或uigetfile)获取所有TXT文件的列表。 2. 接着,通过循环结构遍历文件列表。在每次迭代中,使用文件操作函数(如fopen和fscanf,或者直接读入整个文件内容后利用str2num转换为数值矩阵)读取每个TXT文件的内容。 3. 读取文件内容后,使用eval函数来执行动态命令或表达式。这可以是直接从字符串转换为矩阵,或者根据内容执行更复杂的操作。 4. 如果处理的数据量较大,应当注意内存管理和性能优化,避免因一次性加载大量数据导致的资源占用过高等问题。 5. 在完成所有文件的处理后,可对提取的矩阵数据进行进一步分析,如矩阵运算、统计分析、可视化展示等。 6. 最后,不要忘记在使用完毕后关闭所有打开的文件句柄,并清理工作空间,保持良好的程序管理习惯。 为了确保代码的安全性和可维护性,在实际应用中推荐尽可能避免使用eval函数,转而寻找更为安全和直接的处理方法。例如,可以预先确定文件格式和内容结构,编写固定的解析代码处理特定格式的TXT文件,这样可以减少运行时的动态执行风险,并提高代码的可读性和维护性。如果eval函数确实是解决问题的最佳方案,则需要仔细设计其使用方式,确保不会引入外部可控的代码,从而保证程序的安全性。"

下面的这段python代码,哪里有错误,修改一下:import numpy as np import matplotlib.pyplot as plt import pandas as pd import torch import torch.nn as nn from torch.autograd import Variable from sklearn.preprocessing import MinMaxScaler training_set = pd.read_csv('CX2-36_1971.csv') training_set = training_set.iloc[:, 1:2].values def sliding_windows(data, seq_length): x = [] y = [] for i in range(len(data) - seq_length): _x = data[i:(i + seq_length)] _y = data[i + seq_length] x.append(_x) y.append(_y) return np.array(x), np.array(y) sc = MinMaxScaler() training_data = sc.fit_transform(training_set) seq_length = 1 x, y = sliding_windows(training_data, seq_length) train_size = int(len(y) * 0.8) test_size = len(y) - train_size dataX = Variable(torch.Tensor(np.array(x))) dataY = Variable(torch.Tensor(np.array(y))) trainX = Variable(torch.Tensor(np.array(x[1:train_size]))) trainY = Variable(torch.Tensor(np.array(y[1:train_size]))) testX = Variable(torch.Tensor(np.array(x[train_size:len(x)]))) testY = Variable(torch.Tensor(np.array(y[train_size:len(y)]))) class LSTM(nn.Module): def __init__(self, num_classes, input_size, hidden_size, num_layers): super(LSTM, self).__init__() self.num_classes = num_classes self.num_layers = num_layers self.input_size = input_size self.hidden_size = hidden_size self.seq_length = seq_length self.lstm = nn.LSTM(input_size=input_size, hidden_size=hidden_size, num_layers=num_layers, batch_first=True) self.fc = nn.Linear(hidden_size, num_classes) def forward(self, x): h_0 = Variable(torch.zeros( self.num_layers, x.size(0), self.hidden_size)) c_0 = Variable(torch.zeros( self.num_layers, x.size(0), self.hidden_size)) # Propagate input through LSTM ula, (h_out, _) = self.lstm(x, (h_0, c_0)) h_out = h_out.view(-1, self.hidden_size) out = self.fc(h_out) return out num_epochs = 2000 learning_rate = 0.001 input_size = 1 hidden_size = 2 num_layers = 1 num_classes = 1 lstm = LSTM(num_classes, input_size, hidden_size, num_layers) criterion = torch.nn.MSELoss() # mean-squared error for regression optimizer = torch.optim.Adam(lstm.parameters(), lr=learning_rate) # optimizer = torch.optim.SGD(lstm.parameters(), lr=learning_rate) runn = 10 Y_predict = np.zeros((runn, len(dataY))) # Train the model for i in range(runn): print('Run: ' + str(i + 1)) for epoch in range(num_epochs): outputs = lstm(trainX) optimizer.zero_grad() # obtain the loss function loss = criterion(outputs, trainY) loss.backward() optimizer.step() if epoch % 100 == 0: print("Epoch: %d, loss: %1.5f" % (epoch, loss.item())) lstm.eval() train_predict = lstm(dataX) data_predict = train_predict.data.numpy() dataY_plot = dataY.data.numpy() data_predict = sc.inverse_transform(data_predict) dataY_plot = sc.inverse_transform(dataY_plot) Y_predict[i,:] = np.transpose(np.array(data_predict)) Y_Predict = np.mean(np.array(Y_predict)) Y_Predict_T = np.transpose(np.array(Y_Predict))

176 浏览量
161 浏览量

import pandas as pd from sklearn import metrics from sklearn.model_selection import train_test_split import xgboost as xgb import matplotlib.pyplot as plt import openpyxl # 导入数据集 df = pd.read_csv("/Users/mengzihan/Desktop/正式有血糖聚类前.csv") data=df.iloc[:,:35] target=df.iloc[:,-1] # 切分训练集和测试集 train_x, test_x, train_y, test_y = train_test_split(data,target,test_size=0.2,random_state=7) # xgboost模型初始化设置 dtrain=xgb.DMatrix(train_x,label=train_y) dtest=xgb.DMatrix(test_x) watchlist = [(dtrain,'train')] # booster: params={'booster':'gbtree', 'objective': 'binary:logistic', 'eval_metric': 'auc', 'max_depth':12, 'lambda':10, 'subsample':0.75, 'colsample_bytree':0.75, 'min_child_weight':2, 'eta': 0.025, 'seed':0, 'nthread':8, 'gamma':0.15, 'learning_rate' : 0.01} # 建模与预测:50棵树 bst=xgb.train(params,dtrain,num_boost_round=50,evals=watchlist) ypred=bst.predict(dtest) # 设置阈值、评价指标 y_pred = (ypred >= 0.5)*1 print ('Precesion: %.4f' %metrics.precision_score(test_y,y_pred)) print ('Recall: %.4f' % metrics.recall_score(test_y,y_pred)) print ('F1-score: %.4f' %metrics.f1_score(test_y,y_pred)) print ('Accuracy: %.4f' % metrics.accuracy_score(test_y,y_pred)) print ('AUC: %.4f' % metrics.roc_auc_score(test_y,ypred)) ypred = bst.predict(dtest) print("测试集每个样本的得分\n",ypred) ypred_leaf = bst.predict(dtest, pred_leaf=True) print("测试集每棵树所属的节点数\n",ypred_leaf) ypred_contribs = bst.predict(dtest, pred_contribs=True) print("特征的重要性\n",ypred_contribs ) xgb.plot_importance(bst,height=0.8,title='影响糖尿病的重要特征', ylabel='特征') plt.rc('font', family='Arial Unicode MS', size=14) plt.show()

263 浏览量
145 浏览量

import cv2 import torch import argparse from pathlib import Path from models.experimental import attempt_load from utils.general import non_max_suppression, scale_coords from utils.torch_utils import select_device # 定义命令行参数 parser = argparse.ArgumentParser() parser.add_argument('--source', type=str, default='e:/pythonproject/pythonproject/runs/detect/exp2/test1.mp4', help='视频文件路径') parser.add_argument('--weights', type=str, default='e:/pythonproject/pythonproject/best.pt', help='YOLOv5 模型权重文件路径') parser.add_argument('--conf-thres', type=float, default=0.25, help='预测置信度阈值') parser.add_argument('--iou-thres', type=float, default=0.45, help='NMS 的 IoU 阈值') parser.add_argument('--device', default='0', help='使用的 GPU 编号,或者 -1 表示使用 CPU') args = parser.parse_args() # 加载 YOLOv5 模型 device = select_device(args.device) model = attempt_load(args.weights, device=device).to(device).eval() # 加载视频 vid_path = args.source vid_name = Path(vid_path).stem vid_writer = None if vid_path != '0': vid_cap = cv2.VideoCapture(vid_path) else: vid_cap = cv2.VideoCapture(0) assert vid_cap.isOpened(), f'无法打开视频:{vid_path}' # 视频帧循环 while True: # 读取一帧 ret, frame = vid_cap.read() if not ret: break # 对图像进行目标检测 img = torch.from_numpy(frame).to(device) img = img.permute(2, 0, 1).float().unsqueeze(0) / 255.0 pred = model(img)[0] pred = non_max_suppression(pred, args.conf_thres, args.iou_thres, classes=None, agnostic=False) # 处理检测结果 boxes = [] for i, det in enumerate(pred): if len(det): det[:, :4] = scale_coords(img.shape[2:], det[:, :4], frame.shape).round() for xyxy, conf, cls in reversed(det): label = f'{model.names[int(cls)]} {conf:.2f}' boxes.append((int(xyxy[0]), int(xyxy[1]), int(xyxy[2]), int(xyxy[3]), label)) # 绘制矩形框 if len(boxes) > 0: for box in boxes: x1, y1, x2, y2, label = box cv2.rectangle(frame, (x1, y1), (x2, y2), (0, 255, 0), 2) cv2.putText(frame, label, (x1, y1 - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2) # 显示帧 cv2.imshow(vid_name, frame) # 写入输出视频 if vid_writer is None: fourcc = cv2.VideoWriter_fourcc('mp4v') vid_writer = cv2.VideoWriter(f'{vid_name}_output.mp4', fourcc, 30, (frame.shape[1], frame.shape[0]), True) vid_writer.write(frame) # 按下 q 键退出 if cv2.waitKey(1) == ord('q'): break # 释放资源 vid_cap.release() if vid_writer is not None: vid_writer.release() cv2.destroyAllWindows(),请指出这段代码的错误

141 浏览量

# seeds = [2222, 5, 4, 2, 209, 4096, 2048, 1024, 2015, 1015, 820]#11 seeds = [2]#2 num_model_seed = 1 oof = np.zeros(X_train.shape[0]) prediction = np.zeros(X_test.shape[0]) feat_imp_df = pd.DataFrame({'feats': feature_name, 'imp': 0}) parameters = { 'learning_rate': 0.008, 'boosting_type': 'gbdt', 'objective': 'binary', 'metric': 'auc', 'num_leaves': 63, 'feature_fraction': 0.8,#原来0.8 'bagging_fraction': 0.8, 'bagging_freq': 5,#5 'seed': 2, 'bagging_seed': 1, 'feature_fraction_seed': 7, 'min_data_in_leaf': 20, 'verbose': -1, 'n_jobs':4 } fold = 5 for model_seed in range(num_model_seed): print(seeds[model_seed],"--------------------------------------------------------------------------------------------") oof_cat = np.zeros(X_train.shape[0]) prediction_cat = np.zeros(X_test.shape[0]) skf = StratifiedKFold(n_splits=fold, random_state=seeds[model_seed], shuffle=True) for index, (train_index, test_index) in enumerate(skf.split(X_train, y)): train_x, test_x, train_y, test_y = X_train[feature_name].iloc[train_index], X_train[feature_name].iloc[test_index], y.iloc[train_index], y.iloc[test_index] dtrain = lgb.Dataset(train_x, label=train_y) dval = lgb.Dataset(test_x, label=test_y) lgb_model = lgb.train( parameters, dtrain, num_boost_round=10000, valid_sets=[dval], early_stopping_rounds=100, verbose_eval=100, ) oof_cat[test_index] += lgb_model.predict(test_x,num_iteration=lgb_model.best_iteration) prediction_cat += lgb_model.predict(X_test,num_iteration=lgb_model.best_iteration) / fold feat_imp_df['imp'] += lgb_model.feature_importance() del train_x del test_x del train_y del test_y del lgb_model oof += oof_cat / num_model_seed prediction += prediction_cat / num_model_seed gc.collect()解释上面的python代码

159 浏览量

LDAM损失函数pytorch代码如下:class LDAMLoss(nn.Module): def init(self, cls_num_list, max_m=0.5, weight=None, s=30): super(LDAMLoss, self).init() m_list = 1.0 / np.sqrt(np.sqrt(cls_num_list)) m_list = m_list * (max_m / np.max(m_list)) m_list = torch.cuda.FloatTensor(m_list) self.m_list = m_list assert s > 0 self.s = s if weight is not None: weight = torch.FloatTensor(weight).cuda() self.weight = weight self.cls_num_list = cls_num_list def forward(self, x, target): index = torch.zeros_like(x, dtype=torch.uint8) index_float = index.type(torch.cuda.FloatTensor) batch_m = torch.matmul(self.m_list[None, :], index_float.transpose(1,0)) # 0,1 batch_m = batch_m.view((16, 1)) # size=(batch_size, 1) (-1,1) x_m = x - batch_m output = torch.where(index, x_m, x) if self.weight is not None: output = output * self.weight[None, :] target = torch.flatten(target) # 将 target 转换成 1D Tensor logit = output * self.s return F.cross_entropy(logit, target, weight=self.weight) 模型部分参数如下:# 设置全局参数 model_lr = 1e-5 BATCH_SIZE = 16 EPOCHS = 50 DEVICE = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu') use_amp = True use_dp = True classes = 7 resume = None CLIP_GRAD = 5.0 Best_ACC = 0 #记录最高得分 use_ema=True model_ema_decay=0.9998 start_epoch=1 seed=1 seed_everything(seed) # 数据增强 mixup mixup_fn = Mixup( mixup_alpha=0.8, cutmix_alpha=1.0, cutmix_minmax=None, prob=0.1, switch_prob=0.5, mode='batch', label_smoothing=0.1, num_classes=classes) # 读取数据集 dataset_train = datasets.ImageFolder('/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/train', transform=transform) dataset_test = datasets.ImageFolder("/home/adminis/hpy/ConvNextV2_Demo/RAF-DB/RAF/valid", transform=transform_test) 帮我用pytorch实现模型在模型训练中使用LDAM损失函数

308 浏览量