Replicate MLPClassifier() of sklearn in keras

Question

I am new to keras. I was attempting an ML problem. About the data:

It has 5 input features, 4 output classes and about 26000 records.

I had first attempted it using MLPClassifier() as follows:

clf = MLPClassifier(verbose=True, tol=1e-6, batch_size=300, hidden_layer_sizes=(200,100,100,100), max_iter=500, learning_rate_init= 0.095, solver='sgd', learning_rate='adaptive', alpha = 0.002)
clf.fit(train, y_train)

After testing, I usually got a LB score around 99.90. To gain more flexibility over the model, I decided to implement the same model in Keras to start with and then make changes in it in an attempt to increase the LB score. I came up with the following:

model = Sequential()
model.add(Dense(200, input_dim=5, init='uniform', activation = 'relu'))
model.add(Dense(100, init='uniform', activation='relu'))
model.add(Dropout(0.2))
model.add(Dense(100, init='uniform', activation='relu'))
model.add(Dense(100, init='uniform', activation='relu'))
model.add(Dense(4, init='uniform', activation='softmax'))

lrate = 0.095
decay = lrate/125
sgd = SGD(lr=lrate, momentum=0.9, decay=decay, nesterov=True)
model.compile(loss='categorical_crossentropy', optimizer=sgd, metrics=['accuracy'])
hist = model.fit(train, categorical_labels, nb_epoch=125, batch_size=256, shuffle=True,  verbose=2)

The model seems pretty similar to the MLPClassifier() model but the LB scores were pretty disappointing at around 97. Can somebody please tell what exactly was wrong with this model? Or how can we replicate the MLPClassifier model in keras. I think regularisation might be one of the factors that went wrong here.

Edit 1: Loss curve:

Edit 2: Here is the code:

#import libraries
import pandas as pd
from sklearn.neural_network import MLPClassifier
from sklearn.model_selection import train_test_split
from sklearn.metrics import log_loss
from sklearn.preprocessing import MinMaxScaler, scale, StandardScaler, Normalizer

from keras.models import Sequential
from keras.layers import Dense, Dropout
from keras import regularizers
from keras.optimizers import SGD

#load data
train = pd.read_csv("train.csv")
test = pd.read_csv("test.csv")

#generic preprocessing 
#encode as integer
mapping = {'Front':0, 'Right':1, 'Left':2, 'Rear':3}
train = train.replace({'DetectedCamera':mapping})
test = test.replace({'DetectedCamera':mapping})
#renaming column
train.rename(columns = {'SignFacing (Target)': 'Target'}, inplace=True)
mapping = {'Front':0, 'Left':1, 'Rear':2, 'Right':3}
train = train.replace({'Target':mapping})


#split data
y_train = train['Target']
test_id = test['Id']
train.drop(['Target','Id'], inplace=True, axis=1)
test.drop('Id',inplace=True,axis=1)
train_train, train_test, y_train_train, y_train_test = train_test_split(train, y_train)

scaler = StandardScaler()
scaler.fit(train_train)
train_train = scaler.transform(train_train)
train_test = scaler.transform(train_test)
test = scaler.transform(test)

#training and modelling
model = Sequential()
model.add(Dense(200, input_dim=5, kernel_initializer='uniform', activation = 'relu'))
model.add(Dense(100, kernel_initializer='uniform', activation='relu'))
# model.add(Dropout(0.2))
# model.add(Dense(100, init='uniform', activation='relu'))
# model.add(Dense(100, init='uniform', activation='relu'))
model.add(Dropout(0.2))
model.add(Dense(100, kernel_initializer='uniform', activation='relu'))
model.add(Dense(100, kernel_initializer='uniform', activation='relu'))
model.add(Dense(4, kernel_initializer='uniform', activation='softmax'))

lrate = 0.095
decay = lrate/250
sgd = SGD(lr=lrate, momentum=0.9, decay=decay, nesterov=True)
model.compile(loss='categorical_crossentropy', optimizer=sgd, metrics=['accuracy'])
hist = model.fit(train_train, categorical_labels, validation_data=(train_test, categorical_labels_test), nb_epoch=100, batch_size=256, shuffle=True,  verbose=2)

Edit 3: These are the files: train.csv test.csv

Answer 1

To get a bona fide scikit estimator you can use KerasClassifier from tensorflow.keras.wrappers.scikit_learn. For example:

from sklearn.datasets import make_classification
from tensorflow import keras
from tensorflow.keras.layers import Dense
from tensorflow.keras.models import Sequential
from tensorflow.keras.wrappers.scikit_learn import KerasClassifier


X, y = make_classification(
    n_samples=26000, n_features=5, n_classes=4, n_informative=3, random_state=0
)


def build_fn(optimizer):
    model = Sequential()
    model.add(
        Dense(200, input_dim=5, kernel_initializer="he_normal", activation="relu")
    )
    model.add(Dense(100, kernel_initializer="he_normal", activation="relu"))
    model.add(Dense(100, kernel_initializer="he_normal", activation="relu"))
    model.add(Dense(100, kernel_initializer="he_normal", activation="relu"))
    model.add(Dense(4, kernel_initializer="he_normal", activation="softmax"))
    model.compile(
        loss="categorical_crossentropy",
        optimizer=optimizer,
        metrics=[
            keras.metrics.Precision(name="precision"),
            keras.metrics.Recall(name="recall"),
            keras.metrics.AUC(name="auc"),
        ],
    )
    return model


clf = KerasClassifier(build_fn, optimizer="rmsprop", epochs=500, batch_size=300)
clf.fit(X, y)
clf.predict(X)