# Build and Evaluate A Logistic Regression Classifier

Written by Matt Dancho on December 22, 2020

Logistic regression is a simple, yet powerful classification model. In this tutorial, learn how to build a predictive classifier that classifies the age of a vehicle. Then use ggplot to tell the story!

Here are the links to get set up. 👇

## The Story

In this analysis we learn that newer vehicles are MORE EFFICIENT, and we’ll make a data visualization that tells the story.

## How did we make this plot?

1. Our logistic regression classifier modeled the data
2. We used VIP to find the most important features
3. We visualized with ggplot 💥

## Making a Logistic Regression Classifier

Logistic regression is a must-know tool in your data science arsenal.

• Logistic Regression is easy to explain
• The classifier has no tuning parameters (no knobs that need adjusted)

Simply split our dataset, train on the training set, evaluate on the testing set.

Folks, it’s that simple. 👏

## Evaluating Our Classification Model

Question: How do we know our if our model is good?
Answer: Area Under the Curve (AUC)!

• Simple measure.
• We want greater than 0.5.
• Closer to 1.0, the better our model is.
• Bonus: ROC Plot - A way to visualize the AUC.

## Telling the Story

What can we do with a Logistic Regression Classifier? Let’s develop a story to communicate our insight!

1. First, find the most important features (predictors) using vip().

2. Next, use ggplot() to make a visualization that focuses on the top features:

• HWY: The highway fuel economy (miles per gallon)
• CLASS: The Vehicle Class (e.g. pickup, subcompact, SUV)

### What did we learn using Logistic Regression?

It’s clear now:

• Vehicles have become more efficient over time.
• Highway fuel economy has gone up for every single class of vehicle.

Your story-telling skills are amazing. Santa approves. 👇

### But if you really want to improve your productivity…

Here’s how to master R programming and become powered by R. 👇

What happens after you learn R for Business.

Your Job Performance Review after you’ve launched your first Shiny App. 👇

This is career acceleration.

### SETUP R-TIPS WEEKLY PROJECT

1. Get the Code

2. Check out the R-Tips Setup Video.

Once you take these actions, you’ll be set up to receive R-Tips with Code every week. =)

## 👇 Top R-Tips Tutorials you might like:

Want these tips every week? Join R-Tips Weekly.