# Tag Archives: python

## ROC Curve & AUC Explained with Python Examples

Last updated: 29th Dec, 2023 Confusion among data scientists regarding ROC Curve and AUC often stems from misunderstanding their relationship. The ROC Curve visualizes true positive vs false positive rates at various thresholds, while AUC quantifies the overall ability of a model to discriminate between classes, with higher values indicating better performance. In this post, you will learn about ROC Curve and AUC concepts along with related concepts such as True positive and false positive rate with the help of Python examples. It is very important to learn ROC, AUC and related concepts as it helps in selecting the most appropriate machine learning classification models based on the model performance. What is …

## Accuracy, Precision, Recall & F1-Score – Python Examples

Last updated: 29th Dec, 2023 Classification models are used in classification problems to predict the target class of the data sample. The classification machine learning models predicts the probability that each instance belongs to one class or another. It is important to evaluate the performance of the classifications model in order to reliably use these models in production for solving real-world problems. The performance metrics include accuracy, precision, recall, and F1-score. Because it helps us understand the strengths and limitations of these models when making predictions in new situations, model performance is essential for machine learning. The most common question asked is what is accuracy, precision, recall and f1 score? In …

## Mean Squared Error or R-Squared – Which one to use?

Last updated: 29th Dec, 2023 As you embark on your journey to understand and evaluate the performance of regression models, it’s crucial to know when to use each of these metrics and what they reveal about your model’s accuracy. In this post, you will learn about the concepts of the mean-squared error (MSE) and R-squared (R2), the difference between them, and which one to use when evaluating the linear regression models. Note that MSE is very closely related to root mean squared error (RMSE) which is also discussed in this blog. You also learn Python examples to understand the concepts in a better manner. For learning the differences between other …

## Introducing Our New Data Science & AI Trends Page

We are thrilled to announce the launch of our dedicated Data Science and AI Trends page at VitalFlux.com! This new resource is designed to be a one-stop hub for data scientists, AI enthusiasts, and anyone passionate about staying at the forefront of technological innovation. What You’ll Find Our Data Science & AI Trends page is more than just a collection of articles; it’s a dynamic resource that aggregates the most insightful and current information from various high-impact sources. Here’s a sneak peek at what you can expect: Web Pages Stay informed with our selection of web pages from leading research institutions, tech news outlets, and individual thought leaders in the …

## Z-test vs T-test: Formula, Examples

Last updated: 18th Dec, 2023 When it comes to statistical tests, z-test and t-test are two of the most commonly used. But what is the difference between z-test and t-test? And when to use z-test vs t-test? In this relation, we also wonder about z-statistics vs t-statistics. And, the question arises around what’s the difference between z-statistics and t-statistics. In this blog post, we will answer all these questions and more! We will start by explaining the difference between z-test and t-test in terms of their formulas. Then we will go over some examples so that you can see how each test is used in practice. As data scientists, it …

## Python – Replace Missing Values with Mean, Median & Mode

Last updated: 18th Dec, 2023 Have you found yourself asking question such as how to deal with missing values in data analysis stage? When working with Python, have you been troubled with question such as how to replace missing values in Pandas data frame? Well, missing values are common in dealing with real-world problems when the data is aggregated over long time stretches from disparate sources, and reliable machine learning modeling demands for careful handling of missing data. One strategy is imputing the missing values, and a wide variety of algorithms exist spanning simple interpolation (mean, median, mode), matrix factorization methods like SVD, statistical models like Kalman filters, and deep …

## Standard Deviation of Population vs Sample

Last updated: 18th Dec, 2023 Have you ever wondered what the difference between standard deviation of population and a sample? Or why and when it’s important to measure the standard deviation of both? In this blog post, we will explore what standard deviation is, the differences between the standard deviation of population and samples, and how to calculate their values using their formula and Python code example. By the end of this post, you should have a better understanding of standard deviation in general and why it’s important to calculate it for both populations and samples. Check out my related post – coefficient of variation vs standard deviation. What is …

## Linear Regression vs. Polynomial Regression: Python Examples

In the realm of predictive modeling and data science, regression analysis stands as a cornerstone technique. It’s essential for understanding relationships in data, forecasting trends, and making informed decisions. This guide delves into the nuances of Linear Regression and Polynomial Regression, two fundamental approaches, highlighting their practical applications with Python examples. What are Linear and Polynomial Regression? In this section, we will learn about what are linear and polynomial regression. What is Linear Regression? Linear Regression is a statistical method used in predictive analysis. It’s a straightforward approach for modeling the relationship between a dependent variable (often denoted as y) and one or more independent variables (denoted as x). In …

## Random Forest vs XGBoost: Which One to Use? Examples

Understanding the differences between XGBoost and Random Forest machine learning algorithm is crucial as it guides the selection of the most appropriate model for a given problem. Random Forest, with its simplicity and parallel computation, is ideal for quick model development and when dealing with large datasets, whereas XGBoost, with its sequential tree building and regularization, excels in achieving higher accuracy, especially in scenarios where overfitting is a concern. This knowledge can be helpful to balance between computational efficiency and predictive performance, tailor models to specific data characteristics, and optimize their approach for either rapid prototyping or precision-focused tasks. In this blog, we will learn the difference between Random Forest …

## Random Forest Classifier – Sklearn Python Example

Last updated: 13th Dec, 2023 A random forest classifier is an ensemble machine learning method which is used for classification problems, and operates by constructing a multitude of decision trees during training and predicting the class label (of the data). In general, Random Forest is popular due to its high accuracy, robustness to overfitting, ability to handle large datasets with numerous features, and its effectiveness for both classification and regression tasks. Its versatility and ease of use make it widely applicable across various domains. Note that Random Forest and Decision Tree classification algorithms are different, although Random Forest is built upon the concept of Decision Trees. In this post, you …

## How to Add Rows & Columns to Pandas Dataframe

Last updated: 12th Dec, 2023 Pandas is a popular data manipulation library in Python, widely used for data analysis and data science tasks. Pandas Dataframe is a two-dimensional labeled data structure with columns of potentially different types, similar to a spreadsheet or SQL table. One of the common tasks in data manipulation when working with Pandas package in Python is how to add new columns and rows to an existing and empty dataframe. It might seem like a trivial task, but choosing the right method to add a row to a dataframe as well as adding a column can significantly impact the performance and efficiency of your code. In this …

## Plot Decision Boundary in Logistic Regression: Python Example

Plotting the decision boundary is a valuable tool for understanding, debugging, and improving machine learning classification models, especially for Logistic Regression. Plotting the decision boundary provides a visual assessment of model complexity, fit, and class separation capability. It enables identifying overfitting and underfitting based on gaps between boundary and data. Comparing decision boundary plots of different models allows direct visual evaluation of their relative performance in separating classes when working with classification problems. For linear models like logistic regression, it specifically helps tune regularization and model complexity to prevent overfitting the training data. Simple linear models like logistic regression will have linear decision boundaries. More complex models like SVM may …

## Forecasting using Linear Regression: Python Example

Linear regression is a simple and widely used statistical method for modeling relationships between variables. While it can be applied to time-series data for trend analysis and basic forecasting, it is not always the most apt method for time-series forecasting due to several limitations. Forecasting using Linear Regression Forecasting using linear regression involves using historical data to predict future values based on the assumption of a linear relationship between the independent variable (time) and the dependent variable (the metric to be forecasted, like CO2 levels discussed in next section). The process typically involves the following steps: Limitations for Linear Regression used in Forecasting Is linear regression most efficient method for …

## Gradient Boosting vs Adaboost Algorithm: Python Example

In this blog post we will delve into the intricacies of two powerful ensemble learning techniques: Gradient Boosting and Adaboost. Both methods are widely recognized for their ability to improve prediction accuracy in machine learning tasks, but they approach the problem in distinct ways. Gradient Boosting is a sophisticated machine learning approach that constructs models in a series, each new model specifically targeting the errors of its predecessor. This technique employs the gradient descent algorithm for error minimization and excels in managing diverse datasets, particularly those with non-linear patterns. Conversely, Adaboost (Adaptive Boosting) is a distinct ensemble strategy that amalgamates numerous simple models to form a robust one. Its defining …

## Feature Importance & Random Forest – Sklearn Python Example

Last updated: 9th Dec, 2023 When building machine learning classification and regression models, understanding which features most significantly impact your model’s predictions can be as crucial as the predictions themselves. This post delves into the concept of feature importance in the context of one of the most popular algorithms available – the Random Forest. Whether used for classification or regression tasks, Random Forest not only offers robust and accurate predictions but also provides insightful metrics to find the most important features in your dataset. You will learn about how to use Random Forest regression and classification algorithms for determining feature importance using Sklearn Python code example. It is very important to …

## Random Forest vs AdaBoost: Difference, Python Example

Last updated: 8th Dec, 2023 In this post, you will learn about the key differences between the AdaBoost and the Random Forest machine learning algorithm. Random Forest and AdaBoost algorithms can be used for both regression and classification problems. Both the algorithms are ensemble learning algorithms that construct a collection of trees for prediction. Random Forest builds multiple decision trees using diverse variables and employs bagging for data sampling and predictions. AdaBoost, on the other hand, creates an ensemble of weak learners, often in the form of decision stumps (simple trees with one node and two leaves). AdaBoost iteratively adjusts these stumps to concentrate on mispredicted areas, often leading to higher …

I found it very helpful. However the differences are not too understandable for me