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April 22, 2016

Analyzing 63 Months of Crimes in London with Alteryx & Tableau


I’m beginning to think Tom Brown might actually think I know what I’m doing. Last week he threw a challenge at me for fire data. Today, he told me about a data set he had of 63 months of crime data in the UK. His requirement was simple: build a viz. Easy enough, until he showed me the data. It was split up into 2899 CSV files in multiple directories.

This is where our good friend Alteryx comes in. In Alteryx all I had to do was use one input tool and tell is to scan all subdirectories. After that I had a tiny bit of cleanup and I was done. Seriously, about 10 minutes of work.

Awesome! I now had a data set of almost 32 million crimes across the UK. But I needed it to be fast and I needed to be able to publish it to Tableau Public. This meant limiting the data set. So I created a group for the London boroughs and filtered my extract to just those. Cool, now only about 5.5 millions crimes.

From there I simply played with lots of vizzes to see if we could find any stories. The end result is the viz below. It’s amazing what you can accomplish in under 2 hours with Alteryx and Tableau. I love it!


  1. Andy, just wondering why you elect to have Tableau create the extract, rather than have Alteryx do it for you? I read in another post (or tweet) that you prefer to let Tableau do that...?

    1. A few reasons:
      1. I want to have the raw data in a simple format in case I need it for something else. Yes, I know alteryx can give me both.
      2. I know if I create it with Tableau, it'll always be using the latest technologies Tableau has added into extracts. I hardly ever see updates to Alteryx so I don't know if they use the same methods.
      3. I often like to have my calculated fields, default field settings, etc as part of my extract. Alteryx can't do that.
      4. Habit and personal preference - I've always done them in Tableau so I'm used to it there.
      5. I run Alteryx in Parallels on a MBA. It takes forever to start up. If I need to create the extract again for some reason, it breaks my flow to go back into Alteryx. They really need either a iOS or web version.

  2. Andy,

    Did you use the Visual Analysis tool kit version of Alteryx or some more expensive version?



    1. This didn't require any add-ons. It's simple data prep.