Standard

You can download the dataset directly.

To plot what the raw data looks like you can run this code;

import numpy as np
import pandas as pd
import matplotlib.pylab as plt

df = pd.read_csv("drawndata1.csv")
X = df[['x', 'y']].values
y = df['z'] == "a"
plt.scatter(X[:, 0], X[:, 1], c=y);

To see the effect from the standard scaler you need to run this;

from sklearn.preprocessing import StandardScaler

X_new = StandardScaler().fit_transform(X)
plt.scatter(X_new[:, 0], X_new[:, 1], c=y);