import numpy as np def loaddata(): X = np.array([[1,'S'],[1,'M'],[1,'M'],[1,'S'], [1, 'S'], [2, 'S'], [2, 'M'], [2, 'M'], [2, 'L'], [2, 'L'], [3, 'L'], [3, 'M'], [3, 'M'], [3, 'L'], [3, 'L']]) y = np.array([-1,-1,1,1,-1,-1,-1,1,1,1,1,1,1,1,-1]) return X, y def Train(trainset,train_labels): m = trainset.shape[0] n = trainset.shape[1] prior_probability = {}# 先验概率 key是类别值,value是类别的概率值 conditional_probability ={}# 条件概率 key的构造:类别,特征,特征值 #类别的可能取值 labels = set(train_labels) # 计算先验概率(此时没有除以总数据量m) for label in labels: prior_probability[label] = len(train_labels[train_labels == label])+1 #计算条件概率 for i in range(m): for j in range(n): # key的构造:类别,特征,特征值 #补充计算条件概率的代码-1; key = str(train_labels[i])+','+str(j)+','+str(trainset[i][j]) conditional_probability[key] = (conditional_probability[key]+1 if (key in conditional_probability) else 1) conditional_probability_final = {} for key in conditional_probability: #补充计算条件概率的代码-2; label = key.split(',')[0] conditional_probability[key]+=1 key1 = int(key.split(',')[1]) Ni = len(set(trainset[:,key1])) conditional_probability_final[key] =conditional_probability[key]/(prior_probability[int(label)]+Ni) # 最终的先验概率(此时除以总数据量m) for label in labels: prior_probability[label] = prior_probability[label]/ (m+len(labels)) return prior_probability,conditional_probability_final,labels def predict(data): result={} for label in train_labels_set: temp=1.0 #补充预测代码; print('result=',result) #排序返回标签值 result[label] = temp*prior_probability[label] for i in range (len(data)): key = str(label)+ ','+str(i)+','+str(data[i]) result[label]*=conditional_probability_final[key] print('result=',result) #排序返回标签值 return sorted(result.items(), key=lambda x: x[1],reverse=True)[0][0] X,y = loaddata() prior_probability,conditional_probability,train_labels_set = Train(X,y) r_label = predict([2,'S']) print(' r_label =', r_label)运行次python代码
时间: 2024-01-23 15:03:45 浏览: 37
这段代码的功能是实现朴素贝叶斯算法进行二分类(标签值为-1和1),对给定的测试数据进行分类预测。其中loaddata()函数载入训练数据集X和标签集y,Train()函数训练得到先验概率prior_probability和条件概率conditional_probability_final,predict()函数根据输入的测试数据进行分类预测。
具体来说,Train()函数中计算了先验概率和条件概率,先验概率是指某个类别在总样本中出现的概率,条件概率是指在给定类别的情况下某个特征出现的概率。predict()函数中根据输入测试数据计算不同类别的概率,并返回最有可能的类别。
该代码需要先调用loaddata()函数载入训练数据,然后调用Train()函数进行训练得到先验概率prior_probability和条件概率conditional_probability_final,最后调用predict()函数进行分类预测。
相关问题
import numpy as np import pickle import math f = open(r'C:\Users\sdnugeo\Desktop\target2.pkl','rb') bi = pickle.load(f) # bi = np.array(bi) data = np.arange(0, 156) print(data) data = data.tolist() # print(data) # 每次抽取1000个数值,共抽取10次 samples = [] c = [] a = 11 r = math.ceil(len(data)/a) print(r) for i in range(a): if len(data) > r : sample = np.random.choice(data, r, replace=False) else: sample = np.random.choice(data, len(data), replace=False) # for s in sample: # data.remove(s) # continue # print(type(sample)) # sample2 = np.array(sample) b = [bi[j] for j in list(sample)] # d = np.array(b) print(type(b)) c.append(b) # c = np.concatenate(c, axis=0) # c = bi[0] print(sample) # print(b) samples.append(sample) for s in sample: data.remove(s) # sample = [s for s in sample if s in data] samples = [np.array(s) for s in samples] samples = np.concatenate(samples, axis=0) c = [np.array(e) for e in c] c = np.concatenate(c, axis=0) # samples = np.array(samples).reshape(-1) print(samples) print(c.shape) 请帮我把这段代码修改成可调用的函数
好的,你想要将这段代码封装成一个函数,可以尝试以下的实现:
```python
import numpy as np
import pickle
import math
def sample_data(filepath):
f = open(filepath, 'rb')
bi = pickle.load(f)
data = np.arange(0, 156)
data = data.tolist()
samples = []
c = []
a = 11
r = math.ceil(len(data)/a)
for i in range(a):
if len(data) > r:
sample = np.random.choice(data, r, replace=False)
else:
sample = np.random.choice(data, len(data), replace=False)
b = [bi[j] for j in list(sample)]
c.append(b)
samples.append(sample)
for s in sample:
data.remove(s)
samples = [np.array(s) for s in samples]
samples = np.concatenate(samples, axis=0)
c = [np.array(e) for e in c]
c = np.concatenate(c, axis=0)
return samples, c
```
你可以将这个函数保存在一个.py文件中,然后在其他的python文件中,通过import导入并调用该函数。调用方法如下:
```python
from your_module import sample_data
filepath = r'C:\Users\sdnugeo\Desktop\target2.pkl'
samples, c = sample_data(filepath)
```
其中,filepath是你想要读取的pickle文件的路径。函数返回两个变量,分别为samples和c。
import pickle import math import numpy as np from torch.utils.data import DataLoader, TensorDataset def sample_data(filepath, idx, path): f = open(filepath, 'rb') bi = pickle.load(f) data = np.arange(0, idx) data = data.tolist() samples = [] bs = [] a = path r = math.ceil(len(data) / a) for i in range(a): if len(data) > r: sample = np.random.choice(data, r, replace=False) else: sample = np.random.choice(data, len(data), replace=False) b = [bi[j] for j in list(sample)] bs.append(b) samples.append(sample) for s in sample: data.remove(s) samples = [np.array(s) for s in samples] samples = np.concatenate(samples, axis=0) bs = [np.array(e) for e in bs] bs = np.concatenate(bs, axis=0) return samples, bs如何让每一次for循环中的b值都能单独进行一次深度学习的dataloader,最后遍历完for循环中所有的b值
你可以在for循环中将每个b值转换为一个TensorDataset对象,并将它们放入一个列表中,最后使用DataLoader将它们组成一个batch。以下是示例代码:
```
import pickle
import math
import numpy as np
import torch
from torch.utils.data import DataLoader, TensorDataset
def sample_data(filepath, idx, path, batch_size):
f = open(filepath, 'rb')
bi = pickle.load(f)
data = np.arange(0, idx)
data = data.tolist()
samples = []
bs = []
dataloader_list = [] # 用于存放每个b值的dataloader
a = path
r = math.ceil(len(data) / a)
for i in range(a):
if len(data) > r:
sample = np.random.choice(data, r, replace=False)
else:
sample = np.random.choice(data, len(data), replace=False)
b = [bi[j] for j in list(sample)]
bs.append(b)
samples.append(sample)
for s in sample:
data.remove(s)
# 将b值转换为TensorDataset对象
dataset = TensorDataset(torch.Tensor(b))
# 创建dataloader
dataloader = DataLoader(dataset, batch_size=batch_size, shuffle=True)
dataloader_list.append(dataloader)
samples = [np.array(s) for s in samples]
samples = np.concatenate(samples, axis=0)
bs = [np.array(e) for e in bs]
bs = np.concatenate(bs, axis=0)
# 遍历dataloader_list中的所有dataloader
for dataloader in dataloader_list:
for batch in dataloader:
# 在这里对每个batch进行深度学习操作
pass
return samples, bs
```
在上面的代码中,我们使用`TensorDataset`将每个b值转换为一个数据集对象。然后,使用`DataLoader`将每个数据集组成一个batch,并将它们放入一个列表中。最后,我们遍历dataloader_list中的所有dataloader并对它们进行深度学习操作。注意,你需要根据你的具体情况设置batch_size参数。