135个数据作为训练集,15个数据为测试集,lookback=10,那batchsize是多少
时间: 2024-03-04 15:51:43 浏览: 21
由于 lookback=10,每个时间步需要10个数据作为输入,因此在训练集中,我们可以从第10个数据开始构建第一个样本,直到第126个数据。这样共有117个样本。对于测试集,同样地从第10个数据开始构建第一个样本,直到第15个数据。这样共有6个样本。
在确定 batchsize 时,我们需要考虑模型的内存限制和训练效率。一般来说,较大的 batchsize 可以加快训练速度,但可能会导致内存不足。而较小的 batchsize 虽然可以避免内存问题,但可能会导致训练速度变慢。
在这种情况下,我们可以根据内存限制和训练效率来选择一个适当的 batchsize。假设我们的内存限制为 128MB,每个数据点的大小为 4 字节(32 位浮点数),则每个 batch 的大小应该为:
batchsize = 内存限制 / (数据点大小 * (lookback + 1)) = 128MB / (4B * 11) ≈ 294
因此,我们可以选择 batchsize 为 294,这样可以保证内存充足,同时也可以加快训练速度。当然,实际选择的 batchsize 还需要根据具体情况进行调整。
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写一个python Flask销售预测系统中,有一个suanfa.py文件:先读取shuju.csv (共有24条数据,包含Date(object)(yyyy/mm)和TotalPrice(float64)两个属性), 然后用scaler将TotalPrice进行归一化处理,之后定义一个函数def split_data(data, lookback): 将数据集划分为测试集(0.2)和训练集(0.8),data_raw = data.to_numpy(),lookback = 4, 然后再将划分完成后的测试集和训练集转换为PyTorch张量,然后定义超参数, 定义算法模型model=LSTM()、损失函数和优化器(Adam)然后训练模型求出MSE, 将模型保存;有一个predict.html文件:里面有一个日期选择框和一个销售额预测按钮,用户选择好年月后 点击按钮系统就开始调用保存好的模型来预测所选月份的销售额,然后将预测结果返回到前端页面日期选择框下面的结果返回 框中;有一个app.py文件:定义路径。用flask和bootstrap、LayUI写出完整详细代码
suanfa.py代码:
```python
import pandas as pd
import numpy as np
import torch
import torch.nn as nn
from sklearn.preprocessing import MinMaxScaler
# 读取数据
data = pd.read_csv('shuju.csv')
# 归一化处理
scaler = MinMaxScaler()
data['TotalPrice'] = scaler.fit_transform(data['TotalPrice'].values.reshape(-1, 1))
# 划分数据集
def split_data(data, lookback):
data_raw = data.to_numpy()
data = []
for index in range(len(data_raw) - lookback):
data.append(data_raw[index: index + lookback])
data = np.array(data)
test_size = int(np.round(0.2 * data.shape[0]))
train_size = data.shape[0] - test_size
x_train = torch.tensor(data[:train_size, :-1, :])
y_train = torch.tensor(data[:train_size, -1, :])
x_test = torch.tensor(data[train_size:, :-1, :])
y_test = torch.tensor(data[train_size:, -1, :])
return x_train, y_train, x_test, y_test
# 超参数
input_size = 1
hidden_size = 32
num_layers = 2
output_size = 1
num_epochs = 100
learning_rate = 0.01
# 定义模型
class LSTM(nn.Module):
def __init__(self, input_size, hidden_size, num_layers, output_size):
super(LSTM, self).__init__()
self.hidden_size = hidden_size
self.num_layers = num_layers
self.lstm = nn.LSTM(input_size, hidden_size, num_layers, batch_first=True)
self.fc = nn.Linear(hidden_size, output_size)
def forward(self, x):
h0 = torch.zeros(self.num_layers, x.size(0), self.hidden_size).to(device)
c0 = torch.zeros(self.num_layers, x.size(0), self.hidden_size).to(device)
out, _ = self.lstm(x, (h0, c0))
out = out[:, -1, :]
out = self.fc(out)
return out
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model = LSTM(input_size, hidden_size, num_layers, output_size).to(device)
# 损失函数和优化器
criterion = nn.MSELoss()
optimizer = torch.optim.Adam(model.parameters(), lr=learning_rate)
# 训练模型
x_train, y_train, x_test, y_test = split_data(data, lookback=4)
for epoch in range(num_epochs):
inputs = x_train.to(device)
targets = y_train.to(device)
outputs = model(inputs)
loss = criterion(outputs, targets)
optimizer.zero_grad()
loss.backward()
optimizer.step()
if (epoch + 1) % 10 == 0:
print(f'Epoch [{epoch + 1}/{num_epochs}], Loss: {loss.item():.4f}')
# 保存模型
torch.save(model.state_dict(), 'model.pt')
```
predict.html代码:
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>销售预测系统</title>
<!-- 引入layui样式 -->
<link rel="stylesheet" href="https://www.layuicdn.com/layui/css/layui.css">
</head>
<body>
<div class="layui-container">
<div class="layui-row">
<div class="layui-col-md-offset3 layui-col-md-6">
<form class="layui-form">
<div class="layui-form-item">
<label class="layui-form-label">选择日期</label>
<div class="layui-input-block">
<input type="text" name="date" id="date" placeholder="yyyy/mm" autocomplete="off" class="layui-input">
</div>
</div>
<div class="layui-form-item">
<div class="layui-input-block">
<button type="button" class="layui-btn" onclick="predict()">销售额预测</button>
</div>
</div>
</form>
</div>
</div>
<div class="layui-row">
<div class="layui-col-md-offset3 layui-col-md-6">
<div class="layui-form-item">
<label class="layui-form-label">销售额预测结果</label>
<div class="layui-input-block">
<input type="text" name="result" id="result" readonly="readonly" autocomplete="off" class="layui-input">
</div>
</div>
</div>
</div>
</div>
<!-- 引入layui JS -->
<script src="https://www.layuicdn.com/layui/layui.js"></script>
<script>
function predict() {
var date = $("#date").val();
$.ajax({
type: "POST",
url: "/predict",
data: {"date": date},
success: function (data) {
$("#result").val(data);
}
});
}
</script>
</body>
</html>
```
app.py代码:
```python
from flask import Flask, render_template, request, jsonify
import pandas as pd
import numpy as np
import torch
from sklearn.preprocessing import MinMaxScaler
from suanfa import LSTM
app = Flask(__name__)
# 加载模型
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model = LSTM(input_size=1, hidden_size=32, num_layers=2, output_size=1).to(device)
model.load_state_dict(torch.load('model.pt'))
# 读取数据并归一化处理
data = pd.read_csv('shuju.csv')
scaler = MinMaxScaler()
data['TotalPrice'] = scaler.fit_transform(data['TotalPrice'].values.reshape(-1, 1))
# 定义预测函数
def predict(date):
# 获取前4个月的销售额数据
last_4_month = []
for i in range(4):
year, month = date.split('/')
month = int(month) - i
if month <= 0:
year = str(int(year) - 1)
month = 12 + month
if month < 10:
month = '0' + str(month)
else:
month = str(month)
date_str = year + '/' + month
last_4_month.append(data[data['Date'] == date_str]['TotalPrice'].values[0])
last_4_month.reverse()
input_data = torch.tensor(last_4_month).view(1, 4, 1).float().to(device)
# 模型预测
with torch.no_grad():
output = model(input_data)
output = scaler.inverse_transform(output.cpu().numpy())[0][0]
return round(output, 2)
# 定义路由
@app.route('/')
def index():
return render_template('predict.html')
@app.route('/predict', methods=['POST'])
def predict_result():
date = request.form.get('date')
result = predict(date)
return jsonify(result)
if __name__ == '__main__':
app.run(debug=True)
```
在运行完以上代码后,通过访问http://localhost:5000/即可进入销售预测系统。用户选择好年月后点击预测按钮,系统就会调用保存好的模型来预测所选月份的销售额,并将预测结果显示在页面下方的结果返回框中。
python操作resultym.csv数据表(有Date(YYYY/MM)、TotalPrice两列数据),数据表第一行为表头信息,数据表中前27行都有数据,以此为基础,python调用resultym.csv表进行操作:循环调用以resultym.csv为数据集构建的pytorch lstm预测模型(模型实现过程:先读取shuju.csv(共有24条数据,包含Year、Month和TotalPrice三个属性),然后用scaler将TotalPrice进行归一化处理,之后定义一个函数def split_data(data, lookback):将数据集划分为测试集(0.2)和训练集(0.8),data_raw = data.to_numpy(),lookback = 4,然后再将划分完成后的测试集和训练集转换为PyTorch张量,然后定义超参数,定义算法模型model=LSTM()、损失函数和优化器(Adam)然后训练模型),该模型能够根据Date值来预测TotalPrice值,然后将第一次预测出的y_test_pred赋值给B26、将第二次预测出的值赋给B27、将第三次预测出的值赋给B28,一直循环直到求出B50的数值。每预测出一个值就在表的最后一行插入一组数据,插入的数据为:Date插入的值按照前面的年月往下延(即按照2023/03、2023/04、2023/05········2025/01的顺序),TotalPrice插入的值定义为2222222.5。直到求出第50行的数值,脚本停止运行。
首先,我们需要导入相关的库和模块:
```python
import pandas as pd
import numpy as np
from sklearn.preprocessing import MinMaxScaler
import torch
import torch.nn as nn
import torch.optim as optim
from torch.autograd import Variable
```
然后,我们需要读取resultym.csv文件,获取前27行数据,以及读取shuju.csv文件,获取24条数据:
```python
# 读取resultym.csv文件
data = pd.read_csv('resultym.csv', header=0, usecols=[0, 1])
data = data.iloc[:27]
# 读取shuju.csv文件
data_raw = pd.read_csv('shuju.csv', header=0, usecols=[1, 2])
```
接下来,我们需要对TotalPrice进行归一化处理,并定义split_data函数,将数据集划分为测试集和训练集:
```python
# 对TotalPrice进行归一化处理
scaler = MinMaxScaler()
data['TotalPrice'] = scaler.fit_transform(data['TotalPrice'].values.reshape(-1, 1))
# 定义split_data函数,将数据集划分为测试集和训练集
def split_data(data, lookback):
# 生成输入序列和输出序列
X, y = [], []
for i in range(len(data)-lookback-1):
a = data[i:(i+lookback), 0]
X.append(a)
y.append(data[i + lookback, 0])
return np.array(X), np.array(y)
# 将数据集划分为测试集和训练集
lookback = 4
X_train, y_train = split_data(data['TotalPrice'].values.reshape(-1, 1), lookback)
X_test, y_test = split_data(data_raw['TotalPrice'].values.reshape(-1, 1), lookback)
# 将划分完成后的测试集和训练集转换为PyTorch张量
X_train = torch.from_numpy(X_train).type(torch.Tensor)
X_test = torch.from_numpy(X_test).type(torch.Tensor)
y_train = torch.from_numpy(y_train).type(torch.Tensor)
y_test = torch.from_numpy(y_test).type(torch.Tensor)
# 对张量进行reshape操作
X_train = Variable(X_train.view(-1, 1, lookback))
X_test = Variable(X_test.view(-1, 1, lookback))
y_train = Variable(y_train)
y_test = Variable(y_test)
```
然后,我们需要定义超参数、算法模型、损失函数和优化器:
```python
# 定义超参数
input_dim = 1
hidden_dim = 2
num_layers = 1
output_dim = 1
num_epochs = 1000
learning_rate = 0.01
# 定义算法模型
class LSTM(nn.Module):
def __init__(self, input_dim, hidden_dim, num_layers, output_dim):
super(LSTM, self).__init__()
self.hidden_dim = hidden_dim
self.num_layers = num_layers
self.lstm = nn.LSTM(input_dim, hidden_dim, num_layers, batch_first=True)
self.fc = nn.Linear(hidden_dim, output_dim)
def forward(self, x):
h0 = Variable(torch.zeros(self.num_layers, x.size(0), self.hidden_dim))
c0 = Variable(torch.zeros(self.num_layers, x.size(0), self.hidden_dim))
out, (hn, cn) = self.lstm(x, (h0.detach(), c0.detach()))
out = self.fc(out[:, -1, :])
return out
model = LSTM(input_dim=input_dim, hidden_dim=hidden_dim, output_dim=output_dim, num_layers=num_layers)
# 定义损失函数和优化器
criterion = nn.MSELoss()
optimizer = optim.Adam(model.parameters(), lr=learning_rate)
```
接下来,我们需要训练模型,并循环调用模型进行预测,将预测出的值插入到resultym.csv表格的最后一行:
```python
# 训练模型
for epoch in range(num_epochs):
outputs = model(X_train)
optimizer.zero_grad()
loss = criterion(outputs, y_train)
loss.backward()
optimizer.step()
if epoch % 100 == 0:
print("Epoch: %d, loss: %1.5f" % (epoch, loss.item()))
# 循环调用模型进行预测
for i in range(24):
x = X_test[i].unsqueeze(0)
y_test_pred = model(x).item()
y_test = torch.cat([y_test, torch.Tensor([y_test_pred])])
data = data.append({'Date': '2023/'+str(int(data_raw.iloc[i, 1])+1).zfill(2), 'TotalPrice': 2222222.5}, ignore_index=True)
# 将预测出的值插入到resultym.csv表格的最后一行
for i in range(26, 51):
x = data['TotalPrice'][i-lookback:i].values.reshape(-1, 1)
x = scaler.transform(x)
x = torch.from_numpy(x).type(torch.Tensor)
x = Variable(x.view(-1, 1, lookback))
y_pred = model(x).item()
y_pred = scaler.inverse_transform(np.array([[y_pred]]))
data = data.append({'Date': '2023/'+str(int(data_raw.iloc[i-lookback, 1])+1).zfill(2), 'TotalPrice': y_pred[0][0]}, ignore_index=True)
```
最后,我们将处理后的结果保存到resultym.csv文件中:
```python
# 将处理后的结果保存到resultym.csv文件中
data.to_csv('resultym.csv', index=False)
```