Convert MLPRegressor of scikit-learn to pytorch model
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Q:How to convert sklearn's MLPRegressor to pytorch's MLP model which has the same weights?
To convert a scikit-learn MLPRegressor model to a PyTorch MLP model with the same weights, you can follow these steps:
First, you will need to install PyTorch. You can do this by following the instructions on the PyTorch website (https://pytorch.org/).
Next, you will need to extract the weights and biases of the scikit-learn MLPRegressor model. You can do this by accessing the coefs_ and intercepts_ attributes of the model. These attributes contain the weights and biases of the model, respectively.
Once you have the weights and biases, you can create a PyTorch MLP model with the same architecture as the scikit-learn MLPRegressor model. You can do this by defining a PyTorch model class that inherits from nn.Module and implementing the __init__ and forward methods. In the __init__ method, you can define the layers of the MLP model and initialize the weights and biases with the values extracted from the scikit-learn model.
After you have defined the PyTorch MLP model, you can use it just like any other PyTorch model. You can train it, evaluate it, and make predictions with it.
Here is an example of how you might implement this in code:
code:Python
import torch
import torch.nn as nn
class MLP(nn.Module):
def __init__(self, input_size, hidden_sizes, output_size, weights, biases):
super().__init__()
self.input_size = input_size
self.output_size = output_size
self.hidden_sizes = hidden_sizes
self.layers = nn.ModuleList()
self.layers.append(nn.Linear(input_size, hidden_sizes0))
self.activation = nn.Sigmoid()
for i in range(1,len(hidden_sizes)-1):
self.layers.append(nn.Linear(hidden_sizesi, hidden_sizesi+1))
self.layers.append(nn.Linear(hidden_sizes-1, output_size))
for i, layer in enumerate(self.layers):
layer.weight.data = torch.Tensor(weightsi.T)
layer.bias.data = torch.Tensor(biasesi)
def forward(self, x):
for i, layer in enumerate(self.layers:-1):
x = self.activation(layer(x))
return self.layers-1(x)
# Load the scikit-learn MLPRegressor model
from sklearn.neural_network import MLPRegressor
sklearn_model = MLPRegressor(...)
# Extract the weights and biases from the scikit-learn model
weights = sklearn_model.coefs_
biases = sklearn_model.intercepts_
# Define the input size and output size of the PyTorch MLP model
input_size = sklearn_model.coefs_0.shape0
output_size = sklearn_model.coefs_-1.shape1
# Define the hidden sizes of the PyTorch MLP model
hidden_sizes = [coef.shape0 for coef in sklearn_model.coefs_1:]
# Create the PyTorch MLP model
model = MLP(input_size, hidden_sizes, output_size, weights, biases)
# You can now use the PyTorch MLP model like any other PyTorch model
output = model(input)
loss = criterion(output, target)
loss.backward()
optimizer.step()
I hope this helps! Let me know if you have any questions.