Felipe's Data Science Blog

Mit 06 Dezember 2017

Using K-means on images

Posted by Felipe in posts   

Playing around with K-means clustering and images

I wanted to see what kind of machine learning tools can be used on maps (I like maps). My first thought was "I can't go about labeling each pixel on a map or satellite image, that would take forever". My next though was "I should use an unsupervised algorithm". Of course, this a vast field of study (duh!) and there are tons of applications of unsupervised algorithms to imaging. I'm going to try to see if K-means clustering can distinguish features in images. This should be fun, because unlike many other applications of clustering, the results here will be totally visual.

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Don 02 November 2017

LOO cross-validation with python

Posted by Felipe in posts   

There is a type of cross-validation procedure called leave one out cross-validation (LOOCV). It is very similar to the more commonly used $k-fold$ cross-validation. In fact, LOOCV can be seen as a special case of $k-fold$ CV with $k=n$, where n is the number of data points. In other words, LOOCV trains the statistical model on every possible set containing $n-1$ data points and then tests it on the $n^{th}$ point.

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