torchkeras 1.3

pytorch ❤️ keras

1，Introduction

The torchkeras library is a simple tool for training neural network in pytorch jusk like in a keras style.

With torchkeras, You need not to write your training loop with many lines of code, all you need to do is just

like this three steps as below:

(i) create your model as a subclass of torchkeras.Model rather than torch.nn.Module.

(ii) compile your model to bind the loss function, the optimizer and the metrics function.

(iii) fit your model with the training data and validate data.

This project seems somehow powerful, but the source code is very simple.

Actually, less than 300 lines of Python code.

If you want to understand or modify some details of this project, feel free to read and change the source code!!!

2, Use example

You can install torchkeras using pip: pip install torchkeras

Here is a complete examples using torchkeras!

import numpy as np 
import pandas as pd 
from matplotlib import pyplot as plt
import torch
from torch import nn
import torch.nn.functional as F
from torch.utils.data import Dataset,DataLoader,TensorDataset

from torchkeras import Model,summary #Attention this line!

(1) prepare data

%matplotlib inline
%config InlineBackend.figure_format = 'svg'

#number of samples
n_positive,n_negative = 2000,2000

#positive samples
r_p = 5.0 + torch.normal(0.0,1.0,size = [n_positive,1]) 
theta_p = 2*np.pi*torch.rand([n_positive,1])
Xp = torch.cat([r_p*torch.cos(theta_p),r_p*torch.sin(theta_p)],axis = 1)
Yp = torch.ones_like(r_p)

#negative samples
r_n = 8.0 + torch.normal(0.0,1.0,size = [n_negative,1]) 
theta_n = 2*np.pi*torch.rand([n_negative,1])
Xn = torch.cat([r_n*torch.cos(theta_n),r_n*torch.sin(theta_n)],axis = 1)
Yn = torch.zeros_like(r_n)

#concat positive and negative samples
X = torch.cat([Xp,Xn],axis = 0)
Y = torch.cat([Yp,Yn],axis = 0)


#visual samples
plt.figure(figsize = (6,6))
plt.scatter(Xp[:,0],Xp[:,1],c = "r")
plt.scatter(Xn[:,0],Xn[:,1],c = "g")
plt.legend(["positive","negative"]);

# split samples into train and valid data.
ds = TensorDataset(X,Y)
ds_train,ds_valid = torch.utils.data.random_split(ds,[int(len(ds)*0.7),len(ds)-int(len(ds)*0.7)])
dl_train = DataLoader(ds_train,batch_size = 100,shuffle=True,num_workers=2)
dl_valid = DataLoader(ds_valid,batch_size = 100,num_workers=2)

(2) create the model

class DNNModel(Model):  ### Attention here
    def __init__(self):
        super(DNNModel, self).__init__()
        self.fc1 = nn.Linear(2,4)
        self.fc2 = nn.Linear(4,8) 
        self.fc3 = nn.Linear(8,1)

    def forward(self,x):
        x = F.relu(self.fc1(x))
        x = F.relu(self.fc2(x))
        y = nn.Sigmoid()(self.fc3(x))
        return y

model = DNNModel()
model.summary(input_shape =(2,))

----------------------------------------------------------------
        Layer (type)               Output Shape         Param #
================================================================
            Linear-1                    [-1, 4]              12
            Linear-2                    [-1, 8]              40
            Linear-3                    [-1, 1]               9
================================================================
Total params: 61
Trainable params: 61
Non-trainable params: 0
----------------------------------------------------------------
Input size (MB): 0.000008
Forward/backward pass size (MB): 0.000099
Params size (MB): 0.000233
Estimated Total Size (MB): 0.000340
----------------------------------------------------------------

(3) Train the model

# define metric
def accuracy(y_pred,y_true):
    y_pred = torch.where(y_pred>0.5,torch.ones_like(y_pred,dtype = torch.float32),
                      torch.zeros_like(y_pred,dtype = torch.float32))
    acc = torch.mean(1-torch.abs(y_true-y_pred))
    return acc

# if gpu is available, use gpu
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")

model.compile(loss_func = nn.BCELoss(),optimizer= torch.optim.Adam(model.parameters(),lr = 0.01),
             metrics_dict={"accuracy":accuracy},device = device)

dfhistory = model.fit(30,dl_train = dl_train,dl_val = dl_valid,log_step_freq = 20)

Start Training ...

================================================================================2020-06-21 20:40:23
{'step': 10, 'loss': 0.217, 'accuracy': 0.905}
{'step': 20, 'loss': 0.215, 'accuracy': 0.914}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   1   | 0.212 |  0.914   |  0.186   |    0.927     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:23
{'step': 10, 'loss': 0.211, 'accuracy': 0.912}
{'step': 20, 'loss': 0.193, 'accuracy': 0.919}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   2   | 0.194 |  0.919   |  0.188   |    0.935     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:23
{'step': 10, 'loss': 0.217, 'accuracy': 0.913}
{'step': 20, 'loss': 0.205, 'accuracy': 0.92}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   3   | 0.195 |  0.921   |  0.176   |    0.931     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:23
{'step': 10, 'loss': 0.164, 'accuracy': 0.932}
{'step': 20, 'loss': 0.197, 'accuracy': 0.917}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   4   | 0.197 |  0.917   |  0.178   |    0.935     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:24
{'step': 10, 'loss': 0.192, 'accuracy': 0.926}
{'step': 20, 'loss': 0.182, 'accuracy': 0.931}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   5   | 0.193 |  0.924   |  0.188   |    0.928     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:44
{'step': 10, 'loss': 0.175, 'accuracy': 0.932}
{'step': 20, 'loss': 0.188, 'accuracy': 0.924}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   97  | 0.184 |  0.923   |  0.176   |    0.935     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:44
{'step': 10, 'loss': 0.21, 'accuracy': 0.913}
{'step': 20, 'loss': 0.192, 'accuracy': 0.918}

 +-------+------+----------+----------+--------------+
| epoch | loss | accuracy | val_loss | val_accuracy |
+-------+------+----------+----------+--------------+
|   98  | 0.19 |  0.922   |  0.179   |    0.934     |
+-------+------+----------+----------+--------------+

================================================================================2020-06-21 20:40:45
{'step': 10, 'loss': 0.186, 'accuracy': 0.923}
{'step': 20, 'loss': 0.181, 'accuracy': 0.928}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|   99  | 0.182 |  0.926   |  0.178   |    0.938     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:45
{'step': 10, 'loss': 0.16, 'accuracy': 0.93}
{'step': 20, 'loss': 0.173, 'accuracy': 0.93}

 +-------+-------+----------+----------+--------------+
| epoch |  loss | accuracy | val_loss | val_accuracy |
+-------+-------+----------+----------+--------------+
|  100  | 0.185 |  0.925   |  0.174   |    0.936     |
+-------+-------+----------+----------+--------------+

================================================================================2020-06-21 20:40:45
Finished Training...

# visual the results
fig, (ax1,ax2) = plt.subplots(nrows=1,ncols=2,figsize = (12,5))
ax1.scatter(Xp[:,0],Xp[:,1], c="r")
ax1.scatter(Xn[:,0],Xn[:,1],c = "g")
ax1.legend(["positive","negative"]);
ax1.set_title("y_true")

Xp_pred = X[torch.squeeze(model.forward(X)>=0.5)]
Xn_pred = X[torch.squeeze(model.forward(X)<0.5)]

ax2.scatter(Xp_pred[:,0],Xp_pred[:,1],c = "r")
ax2.scatter(Xn_pred[:,0],Xn_pred[:,1],c = "g")
ax2.legend(["positive","negative"]);
ax2.set_title("y_pred")

(4) evaluate the model

%matplotlib inline
%config InlineBackend.figure_format = 'svg'

import matplotlib.pyplot as plt

def plot_metric(dfhistory, metric):
    train_metrics = dfhistory[metric]
    val_metrics = dfhistory['val_'+metric]
    epochs = range(1, len(train_metrics) + 1)
    plt.plot(epochs, train_metrics, 'bo--')
    plt.plot(epochs, val_metrics, 'ro-')
    plt.title('Training and validation '+ metric)
    plt.xlabel("Epochs")
    plt.ylabel(metric)
    plt.legend(["train_"+metric, 'val_'+metric])
    plt.show()

plot_metric(dfhistory,"loss")

plot_metric(dfhistory,"accuracy")

model.evaluate(dl_valid)

{'val_loss': 0.13576620258390903, 'val_accuracy': 0.9441666702429453}

(5) use the model

model.predict(dl_valid)[0:10]

tensor([[0.8767],
        [0.0154],
        [0.9976],
        [0.9990],
        [0.9984],
        [0.0071],
        [0.3529],
        [0.4061],
        [0.9938],
        [0.9997]])

for features,labels in dl_valid:
    with torch.no_grad():
        predictions = model.forward(features)
        print(predictions[0:10])
    break

tensor([[0.9979],
        [0.0011],
        [0.9782],
        [0.9675],
        [0.9653],
        [0.9906],
        [0.1774],
        [0.9994],
        [0.9178],
        [0.9579]])

(6) save the model

# save the model parameters

torch.save(model.state_dict(), "model_parameter.pkl")

model_clone = DNNModel()
model_clone.load_state_dict(torch.load("model_parameter.pkl"))

model_clone.compile(loss_func = nn.BCELoss(),optimizer= torch.optim.Adam(model.parameters(),lr = 0.01),
             metrics_dict={"accuracy":accuracy})

model_clone.evaluate(dl_valid)

{'val_loss': 0.17422042911251387, 'val_accuracy': 0.9358333299557368}