# Machine Learning Regression Analysis Explained

By Akssar

Last updated on Feb 28 2022 ## Guide to Regression Analysis in Machine Learning

Gone are the days when mankind was gambling on the future by planning outcomes and necessary actions required based on intuition. With the advent of mathematics combined with the advances in computers, we have reached an era of informed and scientific predictions of future outcomes. This is done by using computers to analyze data and apply mathematics to predict outcomes.

The models used for this purpose are called machine learning regressions and are seen as a subset of artificial intelligence. The concept of machine learning ranges from simple linear regression to more complex ideas like support vector regression which is done using a support vector machine for regression. Their applications are endless and it is an exciting field of study.

This article will give you a comprehensive introduction to the world of machine learning regressions.

### What is Machine Learning?

To a layman, Machine learning and machine learning regression would sound a lot like artificial intelligence, to others, it might sound like calculated gambling. But it is quite simply mathematics. It is simply the use of computer algorithms to look at a large pool of data to try and make an informed prediction of a future outcome. These algorithms have the ability to constantly evolve with the gathering of more and more data. Machine learning models are built based on a large sample of data which is also called the “training data”. Machine learning has widespread uses and applications and is applied in everything ranging from the weather to medicine to handling the supply chain. Its ability to produce “predictive analytics” is used to make informed and scientific predictions of future outcomes and has applications in everything from business solutions to disaster management to fantasy sports. We can clearly see that Machine learning regressions are one of the key tools available to us in helping plan for and mitigate future issues in a wide array of fields.

### What is Machine Learning Regression?

Regression can be, in the simplest terms, thought of as a way to make sense of dotted data points on a graph sheet. The goal of machine learning regressions is to find the best connecting curve, or even a line, unifying the data. The idea is to use the data to establish a relationship between a solid dependable variable and one or more independent variables. It falls under a subset called supervised learning where such algorithms are trained using some output labels as well as some input features. All this is done to establish an estimate of how change in a variable can affect another variable(s).

What is regression analysis in machine learning?

As mentioned above, regression is carried out to try and understand the link between variables. It is carried out using the data and is called regression analysis. It is one of the fundamental uses of regression algorithms and is used for prediction. It has applications in predicting various things which are affected by multiple variables, like weather, real-estate, sales, etc. When it comes to making predictions, it is important to always remember that “correlation is not causation”. This means that while looking to find a link between variable data, we must remember to try and understand whether the change in variables is due to a change in the other variable or independent of it. For example, it might rain every time you wear a red shirt, but the rain is clearly not caused due to the fact that you wore a redshirt. While this might be an easy to distinguish example, one must be more careful while analyzing more complex and independent variables. Regression analysis is evaluated keeping three metrics under important consideration. These are variance, bias, and error.

Variance –

The value by which the predicted outcome of the algorithm changes with a change in training data is called a variance. When different data is used, the nature of prediction or rather the logic behind prediction needs to remain the same. That is, machine learning regression models must be generic. To ensure that the error level is low, the variance needs to be low as well. This is the reason regression machine learning models are aimed at being generic.

Let’s take the example of building a machine-learning algorithm to predict the weather. We would make an algorithm predicting the weather using various factors like humidity, wind, etc. We would feed it data from a certain place to build the algorithm.

However, the issue here is that the algorithm is making predictions based on data from one specific place and would be curated to that specific place. Now if we input data from another place, and the algorithm makes a prediction, the difference in prediction for that place and the other place, would be the variance. We can see why it is important to make the algorithm generic in this example. Bias –

The algorithm might develop the tendency over a period of time to learn wrong things by fixating on a specific part of data, and not the entire information, on a consistent basis. For the algorithm to be accurate, the level of bias needs to be low. This can be done by ensuring that the data set is as accurate as possible.

There is something called the Bias-Variance trade-off. They are almost inversely proportional with the general trend of one being low if the other is higher. If the regression models in machine learning are simple and based on a lesser number of parameters, then bias would be high and variance would be low.

The variance is low and bias is higher when the model has multiple complex parameters. The ultimate goal is to get both these metrics as low and close as possible.

Error –

Error is another metric that is more of a predictive analytics system. Accuracy and error are seen together to analyze the quality of the algorithm model. Error is basically the difference between predicted data and actual data. Accuracy is the calculation of the percentage of predictions that the algorithm got right.

The ideal model should have low variance, low bias, low error, and high accuracy. To achieve this the model is provided with a sample dataset or “training data” from which it can learn and subsequently the predictions are analyzed using test data.

#### Types of Regression in Machine Learning

There are various ways in which regression analysis can be carried out using the idea of machine learning regression. To study these ways, it is important to make classification and regression in machine learning is no exception. These have been discussed in brief below.

##### Linear Regression

Linear regression is the most basic form of regression models in machine learning and is the idea of analyzing data over a linear graph. It finds the linear relationship between an independent variable and a known dependent variable. It also takes into account a bias constant. The idea of regression in ML is to get a best-fit line for the data points, that is merely finding the best way to link the data points.

Types of Linear Regression in Machine Learning

Linear regression in machine learning is further subdivided into three types.

Simple Linear Regression

It is the simplest form of machine learning regressions. Simple linear regression in machine learning tries to establish a linear relationship between two variables, one of which is independent and the other a dependent variable. Ideally, it should lead to a straight line on a graph and any variation or slope can be attributed to factors like bias.

Multiple Linear Regression

It is very similar to simple linear regression. The goal here is the same of forming a linear relationship between variables that would lead to a straight best-fit line on a graph. However, the difference lies in the fact that three variables are taken into consideration. One of the variables is dependent while two independent variables are used. Hence it becomes a multiple linear regression in machine learning.

Multivariate Linear Regression

This is rather self-explanatory. It is another form of linear regression and hence similarly tries to establish a linear relationship and on a graph opts to find a straight best-fit line. However here, as indicated by the name, multiple variables are involved in the model.

Polynomial Regression

The linear regression model, while useful, is not effective when dealing with complex data. It is hard to find a link between variables in all data on a straight line. Not all data fits into linear models in machine learning. For such complex systems, the best-fit line needs to be curved to account for the fluctuations in the variables and still keep up the relationship. This is where polynomial regression in machine learning is employed. Regularization is employed in fitting the curve on the data to increase accuracy.

Ridge Regression

When trying to jot data points on a graph to find the relationship between variables, we look to achieve a best-fit line. Ideally, a simple data connection would lead to an ideal curve or a line, however, this does not always occur and can lead to something called as “overfitting”. Overfitting is when the curve is too haphazard as each data point in the outcome or training data is connected minutely point to point. The resultant curve appears too volatile to be used for prediction. Ridge regression in machine learning deals with the problem of overfitting. This is done by placing a constraint or a limit on a co-efficient of the independent variable(s). This is done to make the data be held within a certain limit. This results in the fit being while not totally on point, is devoid of serious error points, ensuring a legible curve that helps overcome overfitting.

Lasso Regression

Lasso regression in machine learning is very similar to ridge regression in its goal. It is aimed at overcoming overfitting but employs a different technique for it. While Ridge puts a cap on the constraints, lasso out-right removes it. It identifies certain constant coefficients of variables and nullifies their value which in turn helps form a more uniform curve. This is considered to be a more efficient way of regularizing the curve.

Logistic Regression Machine Learning

It is using the regression algorithm to help in classification. This is done by applying regression to differentiation factors instead of trying to link them using data points. This helps in classifying data and can be used to make inventories. This is a logical regression in machine learning as it demonstrates that the algorithm is set out to find the proportionality relation among variables. Conclusion –

Machine learning regression is one of the most advanced models available today to analyze data and predict outcomes. It has widespread applications in a wide range of fields and its benefits are endless. It has empowered mankind to process data like never before and plan in the most informed and scientific way possible.

With its many applications, its demand has soared over the years. In fact, Market and markets predict that the global market for machine learning would be worth USD 9 billion in the year 2022. Learning machines learning and understanding machine learning regression models would be a big boost to the skill-set of any working professional.

A reputed institute like Sprintzeal could help you understand more complex types of machine learning regressions like decision tree regression in machine learning, and random forest regression in machine learning. Consider taking the help of a reputed training platform like Sprintzeal if you are serious about gaining this fascinating and in-demand skill.

Here is an interesting course for you –

AI and Machine Learning Master’s Program

Some interesting articles for more on Machine Learning –

MACHINE LEARNING ALGORITHMS - KNOW THE ESSENTIALS

HOW TO BECOME A MACHINE LEARNING ENGINEER Akssar

A law graduate with an immense passion for research and writing. Loves to travel, read and eat. When not doing that, loves working toward bringing well-researched and informative content to readers. Has experience in, and, is passionate about journalistic pieces, blog posts, review articles, sports coverage, technical research pieces, script-writing, website content, social media marketing, advertising, and creative writing. Sleeps when the ink runs out writing all that.

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