activity as you recall from fyqmbjofe@wbsjbodf@sbujpwe actually captured most of the variance in single dimension maybe the overall size of the flower is all that really matters in classifying itand you can specify that with one feature sogo ahead and modify the results if you are feeling up to it see if you can get away with dimensionsor dimension instead of sogo change that @dpnqpofout to and see what kind of variance ratio you get what happensdoes it makes senseplay around with itget some familiarity with it that is dimensionality reductionprincipal component analysisand singular value decomposition all in action veryvery fancy termsand you knowto be fair it is some pretty fancy math under the hood but as you can seeit' very powerful technique and with scikit-learnit' not hard to apply sokeep that in your tool chest and there you have ita dataset of flower information boiled down to dimensions that we can both easily visualizeand also still see clear delineations between the classifications that we're interested in sopca works really well in this example againit' useful tool for things like compressionor feature extractionor facial recognition as well sokeep that in your toolbox data warehousing overview nextwe're going to talk little bit about data warehousing this is field that' really been upended recently by the advent of hadoopand some big data techniques and cloud computing soa lot of big buzz words therebut concepts that are important for you to understand let' dive in and explore these conceptslet' talk about elt and etland data warehousing in general this is more of conceptas opposed to specific practical techniqueso we're going to talk about it conceptually butit is something that' likely to come up in the setting of job interview solet' make sure you understand these concepts we'll start by talking about data warehousing in general what is data warehousewellit' basically giant database that contains information from many different sources and ties them together for you for examplemaybe you work at big ecommerce company and they might have an ordering system that feeds information about the stuff people bought into your data warehouse