Clustering With K-Means in Python

The Data Science Lab

A very common task in data analysis is that of grouping a set of objects into subsets such that all elements within a group are more similar among them than they are to the others. The practical applications of such a procedure are many: given a medical image of a group of cells, a clustering algorithm could aid in identifying the centers of the cells; looking at the GPS data of a user’s mobile device, their more frequently visited locations within a certain radius can be revealed; for any set of unlabeled observations, clustering helps establish the existence of some sort of structure that might indicate that the data is separable.

Mathematical background

The k-means algorithm takes a dataset X of N points as input, together with a parameter K specifying how many clusters to create. The output is a set of K cluster centroids and a labeling…

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Supervised and Unsupervised learning

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Wiki Supervised Learning Definition 

        Supervised learning is the Data mining task of inferring a function from labeled training data.The training data consist of a set of training examples. In supervised learning, each example is a pair consisting of an input object (typically a vector) and a desired output value (also called the supervisory signal). A supervised learning algorithm analyzes the training data and produces an inferred function, which can be used for mapping new examples. An optimal scenario will allow for the algorithm to correctly determine the class labels for unseen instances. This requires the learning algorithm to generalize from the training data to unseen situations in a “reasonable” way.

Wiki Unsupervised Learning Definition

In Data mining, the problem of unsupervised learning  is that of trying to find hidden structure…

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Find job through twitter!

Hello Folks!

So, here it goes.. First post! Always wanted to create one blog, even had one in past! But as usual, NO TIME!!! Got some time after a loooooooooooooooong time 😛

Got one !dea.. Finding job through tweets! Yes, some companies do post tweet about job opening. Anyway, it will be fun and informative to play with twitter data.

First of all make sure you got following checklist completed!

• Python (YES! we are gonna use this baby, it’s fast and super easy)
  • Download: Python 2.7.x by Anaconda

That’s it! Nothing else needed! Just open IPython Notebook by launching “Launcher” after installation finished! Create new IPython Notebook, it looks like this..

Anaconda launcher, open IPython-notebook

 

new ipython-notebook

Alrighty.. here comes the fun part! Now python stuff starts.. make sure you complete following checklist:

• Create an account on Twitter
• Generate authentication tokens by following the instructions here.
• Add your tokens to the twitter.cfg file. (API Key == Consumer Key)
• Assuming you’ve already installed pip, you can add TwitterAPI with following command: Read more about TwitterAPI!

pip install TwitterAPI

that’s it! Let’s start some codding now..

1) Import necessary files

2) Create Twitter API instance. Add your credentials in ‘twitter.cfg’ file & put it in same folder where your current IPython notebook is placed! here is what you have to add inside that ‘twitter.cfg’ file!

[twitter]
consumer_key: consumer_key
consumer_secret: consumer_secret
access_token: token_number
access_token_secret: token_secret

3) Create request to twitter

4) Create input to enter search query:

5) Create input to enter numbers of tweets we want to fetch from twitter:

6) check the fetched tweets:

7) Print tweets:

DONE!

~ check the whole code on my Github: Code

~ follow on twitter: @iSnehal_SP