I am reading, a machinelearningmastery.com post about improving neural network performance, and I am attempting to normalize my own data set with the tips mentioned in the post using sklearn preprocessing MinMaxScaler.

In my code I am reading a CSV file directly into pandas.

#read CSV file
df = pd.read_csv('C:\\Users\\desktop\\EC\\data.csv', index_col='Date', parse_dates=True)

The snip below is what the data looks like with column names: enter image description here

From the post, I normalize the data with this code below. The process appears to just return a numpy array, but I use Pandas during the machine learning fit process.

from sklearn.preprocessing import MinMaxScaler

# create scaler
scaler = MinMaxScaler()

# fit and transform in one step
df2 = scaler.fit_transform(df)

df2 = pd.DataFrame(df2)

What's happening, is my column names are stripped away and I use column names a lot in dropping & selecting. For example, I fit a lot of models like this process below to differentiate target and input variables.

#Test random Forest

import numpy as np
from sklearn import preprocessing, cross_validation, neighbors
import pandas as pd
from sklearn.ensemble import RandomForestRegressor
from sklearn.externals import joblib
import math

rmses = []
for i in range(2):

    X = np.array(df2.drop(['Demand'],1))
    y = np.array(df2['Demand'])

    offset = int(X.shape[0] * 0.7)
    X_train, y_train = X[:offset], y[:offset]
    X_test, y_test = X[offset:], y[offset:]

    clf = RandomForestRegressor(n_estimators=120, min_samples_split=20)

    clf.fit(X_train, y_train)
    mse = mean_squared_error(y_test, clf.predict(X_test))
    rmse = math.sqrt(mse)
    print("rmse: %.4f" % rmse)


joblib.dump(clf, 'rfrModel.pkl')

But maybe this isn't a bid deal... Sorry not a lot of wisdom here any tips help. Is there another method to madness that I don't need to dependent on column names? If the df2 = scaler.fit_transform(df) leaves columns in place but just removes names, I could just use a column number to .drop - differentiate target & input variables.. Demand is the name of my target variable, and I could just call the second column..., right??

enter image description here


1 Answer 1


You can just use the previous column names for creating a new dataframe

# Use the previous column names from df and assign it to df2   
df2 = pd.DataFrame(df2, columns=df.columns)

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