Day: May 24, 2021

Machine Learning for Beginners in Python: Ridge Regression

Ridge Regression Preliminaries /* Load libraries */ from sklearn.linear_model import Ridge from sklearn.datasets import load_boston from sklearn.preprocessing import StandardScaler Load Boston Housing Dataset /* Load data */ boston = load_boston() X = boston.data y = boston.target Standardize Features /* Standarize features */ scaler = StandardScaler() X_std = scaler.fit_transform(X) Fit Ridge Regression The hyperparameter, αα, lets us …

Machine Learning for Beginners in Python: Linear Regression Using Scikit-Learn

Linear Regression Using Scikit-Learn Preliminaries /* Load libraries */ from sklearn.linear_model import LinearRegression from sklearn.datasets import load_boston import warnings /* Suppress Warning */ warnings.filterwarnings(action=”ignore”, module=”scipy”, message=”^internal gelsd”) Load Boston Housing Dataset /* Load data */ boston = load_boston() X = boston.data y = boston.target Fit A Linear Regression /* Create linear regression */ regr = …

Machine Learning for Beginners in Python: Lasso Regression

Lasso Regression Preliminaries /* Load library */ from sklearn.linear_model import Lasso from sklearn.datasets import load_boston from sklearn.preprocessing import StandardScaler Load Boston Housing Dataset /* Load data */ boston = load_boston() X = boston.data y = boston.target Standardize Features /* Standarize features */ scaler = StandardScaler() X_std = scaler.fit_transform(X) Fit Lasso Regression The hyperparameter, αα, lets us …

Machine Learning for Beginners in Python: What is Effect Of Alpha On Lasso Regression

Effect Of Alpha On Lasso Regression Often we want conduct a process called regularization, wherein we penalize the number of features in a model in order to only keep the most important features. This can be particularly important when you have a dataset with 100,000+ features. Lasso regression is a common modeling technique to do regularization. The …

Machine Learning for Beginners in Python: How to Add Interaction Terms in Linear Regression

Adding Interaction Terms Preliminaries /* Load libraries */ from sklearn.linear_model import LinearRegression from sklearn.datasets import load_boston from sklearn.preprocessing import PolynomialFeatures import warnings /* Suppress Warning */ warnings.filterwarnings(action=”ignore”, module=”scipy”, message=”^internal gelsd”) Load Boston Housing Dataset /* Load the data with only two features */ boston = load_boston() X = boston.data[:,0:2] y = boston.target Add Interaction Term …

Machine Learning for Beginners in Python: Hyperparameter Tuning Using Random Search

Hyperparameter Tuning Using Random Search Preliminaries /* Load libraries */ from scipy.stats import uniform from sklearn import linear_model, datasets from sklearn.model_selection import RandomizedSearchCV Load Iris Dataset /* Load data */ iris = datasets.load_iris() X = iris.data y = iris.target Create Logistic Regression /* Create logistic regression */ logistic = linear_model.LogisticRegression() Create Hyperparameter Search Space /* …

Machine Learning for Beginners in Python: How to Find Best Preprocessing Steps During Model Selection

Find Best Preprocessing Steps During Model Selection We have to be careful to properly handle preprocessing when conducting model selection. First, GridSearchCV uses cross-validation to determine which model has the highest performance. However, in cross-validation we are in effect pretending that the fold held out as the test set is not seen, and thus not part of …

Machine Learning for Beginners in Python: How to Calculate Recall

Recall Preliminaries /* Load libraries */ from sklearn.model_selection import cross_val_score from sklearn.linear_model import LogisticRegression from sklearn.datasets import make_classification Generate Features And Target Data /* Generate features matrix and target vector */ X, y = make_classification(n_samples = 10000, n_features = 3, n_informative = 3, n_redundant = 0, n_classes = 2, random_state = 1) Create Logistic Regression …

Machine Learning for Beginners in Python: How to Calculate Precision

Precision Preliminaries /* Load libraries */ from sklearn.model_selection import cross_val_score from sklearn.linear_model import LogisticRegression from sklearn.datasets import make_classification Generate Features And Target Data /* Generate features matrix and target vector */ X, y = make_classification(n_samples = 10000, n_features = 3, n_informative = 3, n_redundant = 0, n_classes = 2, random_state = 1) Create Logistic Regression …

Machine Learning for Beginners in Python: How to Plot The Validation Curve

Plot The Validation Curve   Preliminaries /* Load libraries */ import matplotlib.pyplot as plt import numpy as np from sklearn.datasets import load_digits from sklearn.ensemble import RandomForestClassifier from sklearn.model_selection import validation_curve Load Digits Dataset /* Load data */ digits = load_digits() /* Create feature matrix and target vector */ X, y = digits.data, digits.target Plot Validation …