## Data and Variables

What do we really mean bydata?

Dataare pieces of information about individuals organized into variables. By anindividual, we mean a particular person or object. By avariable, we mean a particular characteristic of the individual.

Adatasetis a set of data identified with particular circumstances. Datasets are typically displayed in tables, in which rows represent individuals and columns represent variables.

Variables can be classified into one of two types: categorical or quantitative.

Categorical variablestake category or label values and place an individual into one of several groups. Each observation can be placed inonlyone category, and the categories are mutually exclusive.

In our example of medical records, Smoking is a categorical variable, with two groups, since each participant can be categorized only as either a nonsmoker or a smoker. Gender and Race are the two other categorical variables in our medical records example. (Notice that the values of the categorical variable Smoking have been coded as the numbers 1 or 2. It is common to code the values of a categorical variable as numbers, but you should remember that these are just codes. They have no arithmetic meaning (i.e., it does not make sense to add, subtract, multiply, divide, or compare the magnitude of such values).

Quantitative variablestake numerical values and represent some kind of measurement.

In our medical example, Age is an example of a quantitative variable because it can take on multiple numerical values. It also makes sense to think about it in numerical form; that is, a person can be 18 years old or 80 years old. Weight and Height are also examples of quantitative variables.

## Friday, 29 April 2016

## Wednesday, 27 April 2016

## Getting Started in Machine Learning ?

Machine Learning is one of the most intriguing field of computer science. You do not need a degree to learn and practice machine learning. In
fact, you don’t need a degree if you want to explore research in machine
learning. It's fun to learn.

Some great examples of Machine Learning MOOCs include :

- MIT 15.075 Statistical Thinking and Data Analysis
- Stanford CS229 Machine Learning
- Stanford Statistics 315a Modern Applied Statistics: Elements of Statistical Learning
- Caltech Learning from Data
- University of Washington Coursera Specialization

Examples of good textbooks are:

- Machine Learning: The Art and Science of Algorithms that Make Sense of Data
- Machine Learning: A Probabilistic Perspective
- The Elements of Statistical Learning: Data Mining, Inference, and Prediction
- Introduction to Statistical Learning in R

### Once you get started with the courses and books you should start looking out for data to practice on. "Learn and Implement" is the best way to ensure whether you know your stuff or not.

Data can be collected from various sources like Kaggle and TunedIt.

The skills that you learn are applicable in industry, but real-world problems do require more than that. This area of learning is not for everyone, but does offer a lot for those whom it does suit.

Competitions are often held in conjunction with academic conferences. Recent companies have opened up their data to competitions to get more out of the best brains of this world.

## Saturday, 23 April 2016

## What is Machine Learning?

**You :**Ha Ha ! So what exactly is machine learning.

**Me :**Machine Learning, a subfield of computer science.

**You :**-_- I knew this already !

**Me :**Okay, Let me think......

**Me :**It is a field of study which give machines, power to learn from the patterns and analogies and figure out a way to infer or predict from data. It's powerful.

**You :**What is "data" in your context ?

**Me :**Data refers to facts and statistics collected together for reference or analysis.

**You :**You spoke of predictions. How are machine learning and statistics related then ?

**Me :**Machine learning and statistics are closely related fields. Mathematical models and tools of ML have had a long pre-history in statistics.

**You :**You brag about it so much, where is it used ?

**Me :**Ummm... You found this page with the help of Google it uses ML to suggest you this page out of the millions of pages out there. You buy goods online they implement some form of ML to recommend goods to you. And not to forget facebook's news-feed it also uses ML to show the relevant news or activities.

**You :**When you say power to machines what do you mean ?

**Me :**I mean by machine learning we are able to get machines to think.

**You :**How is this possible, machines aren't intelligent and can't think ?

**Me :**Lets say machines are not intelligent because they do not take decisions on their own, but can't we say the same for us. Aren't we doing the same thing. In our life our every decisions are backed up by the experiences ( Data ).

**My Question :**Do we have a proper concept of intelligence ?

## Wednesday, 20 April 2016

As the things get along I will also implement strategies or methods to real life problems that are on kaggle and topcoder.

## Vijay Krishnavanshi

I am a computer science undergraduate from India.

I love to teach, travel and play guitar

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