In data mining, k-means++ is an algorithm for choosing the initial values (or "seeds") for the k-means clustering algorithm. It was proposed in 2007 by David Arthur and Sergei Vassilvitskii, as an approximation algorithm for the NP-hard k-means problem—a way of avoiding the sometimes poor clusterings found by the standard k-means algorithm. It is similar to the first of three seeding methods proposed, in independent work, in 2006 by Rafail Ostrovsky, Yuval Rabani, Leonard Schulman and Chaitanya Swamy. (The distribution of the first seed is different.)
The k-means problem is to find cluster centers that minimize the intra-class variance, i.e. the sum of squared distances from each data point being clustered to its cluster center (the center that is closest to it). Although finding an exact solution to the k-means problem for arbitrary input is NP-hard, the standard approach to finding an approximate solution (often called Lloyd's algorithm or the k-means algorithm) is used widely and frequently finds reasonable solutions quickly.
There comes a time in life when you have to make your decisions
To mould your future because tomorrow is another day
Well I've been sitting, thinking, and I kinda see it this way
I'd really like to be 'man at C & A'
I'd really like to be
I really wanna be
The position was made for me
I think I've got to be
I don't really care if we're in or out of Europe
And I don't give a toss if inflation is up or down
Just give me my Sky TV
All I want is my Ford Capri
And I'll be happier that way
I think I'll spend my time wearing lairy shorts in Essex
I think I'll spend my days burning holes in the ozone layer
And when my children say, 'What did you do for me Dad?'
I'll say, 'Don't ask me kid, I was man at C & A'
You can find a future if you stroll down to the job club
And you can buy anything as long as you're willing to pay
But I get all I want at my local Sainsbury's supermarket
And the rest are at bargain prices
When I shop down at C & A
So when your time comes and you have to make your decisions
To mould your future, because tomorrow's is another day
Then why not join me at the queue down at the check out