Sunday, February 7, 2021

Top Machine Learning algorithms for Beginners

As we all know, around the world all nearly manual tasks becoming fully automated, and all of the things possible only because of AI and Machine Learning. Machine Learning algorithms help computers to work automatically as we do. We living in the era of the technological world where we can see the enhancement of technological advancement over the years. In the coming years, Machine Learning and AI will be the most popular technology in the market that everyone wants to implement in businesses for better productivity. Govt. also started focusing on these technologies and providing investment for AI and Machine Learning. 

An ML algorithm is a method that runs on data and is used to create a machine learning model that is ready for output. Learning tasks can include learning the feature that maps the input to the output, learning the hidden structure in unlabeled data, or 'instance-based learning,' where a class label is created by comparing the new instance (row) to instances stored in memory from the training data. Instance-based learning does not produce an abstraction from particular cases. These algorithms are highly automated and self-modifying because, with the addition of an increased amount of data and with minimal human interaction needed, they continue to evolve over time.

 So here we discuss the best machine learning algorithms for beginners:

 Linear Regression



It demonstrates the connection in the midst of an independent and a dependent variable and deals with continuous values of prediction/estimates. The effect on the dependent variable is described while the independent variable is modified, as a result of which an independent variable is known as the explanatory variable, while the dependent variable is named as the interest of factor. For example, it can be used in the insurance domain for risk assessment to identify the number of applications for users of multiple ages. The predictor value in a simple linear regression is an independent value that has no underlying dependence on any variable. The x and y relationship is described as follows:

Y = mx+c

Here the slope is m and the intercept is c.

 Logistic Regression

Logistic regression is an effective statistical way of modeling one or more explanatory variables for a binomial result. By estimating probabilities using a logistic function, which is the cumulative logistic distribution, it calculates the relationship between the categorical dependent variable and one or more independent variables. 

There are two aspects of Logistic Regression, Hypothesis and Sigmoid Curve. The resulting probability of the occurrence can be derived on the basis of this hypothesis. Data obtained from the hypothesis would then fit into the log function that forms the 'sigmoid' S-shaped curve.

The sigmoid/logistic function is given by the equation below. 

1 / (1 + e^-x)

We write the logistic regression equation as follows— 

y = e^(b0 + b1*x) / {1 + e^(b0 + b1*x)}

The two coefficients of the x input are b0 and b1. Using the maximum probability function, we estimate these coefficients.

 Decision Tree

The decision-tree algorithm is a much more complicated algorithm. A unique advantage of using this algorithm is that it can work not only with problems of classification but also with regression. It is also important to remember that both supervised and non-parametric are (meaning that there are no assumptions with probability distributions of the data). They are easier to understand and easier to visually explain in terms of how they work behind the scenes than other models (thinking of a tree and how its branches split). Decision trees can handle both categorical and numerical data, which is often what is needed for machine learning algorithms in real-world applications.

Naive Bayes

Naive Bayes is a classification based on the Bayes Theorem of conditional probability classifiers. A Naive Bayes classifier assumes that the appearance in a class of a selective feature is unrelated to any other feature's appearance. 

The Bayes Theorem provides a standard technique for the posterior probability estimation of P(c|x), P(c), P(x), and P(x|c). There is an assumption in a Naive Bayes classifier that the effect on a given class(c) of the values of the predictor is independent of other predictor values. The Bayes Theorem has a lot of benefits. It can be implemented easily. In addition, Naive Bayes needs a small amount of data from training and the results are normally correct.

K-means

K-means is an unsupervised algorithm that solves problems in clustering. It measures the centroids of k clusters and assigns the least distance between its centroid and the data point to a data point for that cluster.

How K-means form a cluster:

  • For each cluster, the K-means algorithm picks k points, called centroids. 
  • A cluster with the closest centroids, i.e. k clusters, is formed by each data point.
  • Now, based on the existing cluster members, it produces new centroids.
  • With these latest centroids, the closest distance is determined for each data point. Until the centroids do not change, this process is repeated.

How Determine the value of K:

In K-means, there are clusters and each cluster has a centroid of its own. For that cluster, the sum of the square difference between the centroid and the data points within a cluster is the sum of the square value. Often, if the sum of square values is added for all clusters,  it becomes total within the sum of the square value for the cluster solution.

SVM (Support Vector Machine)

For classification or regression problems, the Support Vector Machine Algorithm is used. In this, by finding a particular line (hyperplane) that separates the data set into multiple classes, the data is divided into different classes. The Support Vector Machine Algorithm tries to find the hyperplane that maximizes the class distance (known as margin maximization) as this increases the probability of more accurately classifying the data.

An SVM algorithm can be created when it comes to trading, which categorises the equity data as a favourable buy, sell or neutral class, and then classifies the test data according to the rules.

 KNN (K Nearest Neighbour)

The KNN algorithm divides the data points into different classes on a basis of similar measure such as the distance function. Then, by searching through the entire data set for the most related instances (the neighbours) of K and summarizing the output variable for these K instances, a prediction is made for a new data point. This could be the mean of the results for regression problems and, for classification problems, this could be the mode (most frequent class). 

The K Nearest Neighbours Algorithm may require a lot of memory or space to store all the data, but it only performs (or learns) a calculation when, just in time, a prediction is required.

 ANN (Artificial Neural Network)

Artificial Neural Networks share the same underlying concept of our nervous system as neurons. It consists of neurons that serve as layer-stacked units that transmit data from the input layer to the final output layer. There is an input layer, a hidden layer and a final output layer on these neural networks. There might be a single layered neural network (Perceptron) or a neural network with several layers.

Human facial recognition is an example of Artificial Neural Networks. Pictures with human faces can be recognised and categorised from "non-facial" images. However, depending on the amount of images in the database, this may take several hours, while the human mind can do this immediately.

Conclusion

From the above discussion, it can be inferred that Machine learning algorithms are models that learn from data and enhance experience regardless of the involvement of human being.

Also Read: Top Best  Machine Learning DataSets For Practicing

So these are the top ML Algorithms that you should know. Apart from this if you want to start your career in Machine Learning and want to do a course then join “Nearlearn”. Nearlearn is the Foremost Machine Learning Training Institute in Bangalore and also the best Artificial Intelligence Training Institute. They provide both online training and classroom training facilities. After completion, of course, they help you to get placement in various companies.

For more information contact us:

Visit: www.nearlearn.com 

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