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Thursday, August 25, 2011

RapidMiner ETL - Sampling, Selecting Rows, Attributes

In this video I show how to sample rows, including balancing class labels, bootstrap sampling. I also show how to filter rows by value, and select a subset of attributes.



You can get the dataset here

RapidMiner ETL - Combining Datasets

In this video, I show how to combine multiple datasets into one, and join columns and append rows.


And We're Back. A video series on ETL with RapidMiner

Back with some more videos! Sorry for the long wait, and thanks for your patience.

This series is on ETL: Extract, Transform, Load with Rapidminer.

The first video shows how to combine multiple datasets into one, by joining columns and appending rows.

The second videos is on sampling and selecting rows and attributes.

More videos coming soon.

Sunday, April 10, 2011

A rainy sunday in downtown Vancouver

My blog should look better on mobile devices now.

Monday, April 4, 2011

Web Scraping with RapidMiner and XPath

In this video I show how to load 500 html files from a previous web crawl, loop through each of them, and use XPath to grab values from each page, and put them in a data table for later analysis.




Web Crawling with RapidMiner

Here is part 2 of my series of videos on web crawling with RapidMiner. In this video I show how to crawl about 500 pages from a site, and discuss user agents, crawling rules, and robot exclusion files.




Sunday, April 3, 2011

More X-Path Goodness

Got a RapidMiner crawling/scraping video coming up, but for now, here are some more X-Path ideas to play with:

//*
return all nodes

//*[contains(., 'Search Text')]
return all nodes that contain Search Text in their content. Case sensitive search.

//div[@id='div1']/following-sibling::*
return the next sibling of a specific node (not sure if this works in RapidMiner)

//div[@id='div1']/../
return the parent node of a specific node

in RapidMiner, precede all nodes with "h:", example: //h:div[@class='abc']/h:a