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F#unctional Londoners Meetup activity

This post is part of the F# Advent Calendar in English 2017 series organized by Sergey Tihon.

A while back I used the Meetup API to build a timeline of F# Meetup events across the globe

The timeline (circa May 2016): 

You can find the source code in this Gist:

For this post I thought it would be fun to use the same Meetup API to focus in on the activity of the F#unctional Londoners Meetup group with an F# script.

The Meetup API returns a JSON response, making it an ideal place to use the FSharp.Data JSON Type Provider:

#r "../packages/FSharp.Data.2.4.3/lib/net45/FSharp.Data.dll"


let [<Literal>] auth= "&sig_id=10286388&status=past%2Cupcoming&sig=19c35f766e5b7a8cc163d2711749d8510a91de33"

let [<Literal>] url=""+auth


type Events = FSharp.Data.JsonProvider< url >

let events = Events.GetSamples()


This gives us types (and intellisense) over the JSON data, so I can make simple queries like the number of events per year:

let eventsbyYear =


    |> Seq.countBy (fun e-> e.LocalDate.Year.ToString())

    |> Seq.sortBy fst


Which returns:

Year Meetups
2010 7
2011 9
2012 11
2013 28
2014 30
2015 26
2016 17
2017 12


Next it would be interesting to get a plot, which can be easily achieved using XPlot:

#r "../packages/Google.DataTable.Net.Wrapper."

#r "../packages/XPlot.GoogleCharts.1.4.2/lib/net45/XPlot.GoogleCharts.dll"

open XPlot.GoogleCharts


let years = eventsbyYear |> Chart.Bar |> Chart.WithTitle "F#unctional Londoners Meetups"


Here’s the nice bar chart result:


And for more detail down to the day we can use a Google Calendar chart:

let options = Options(title = "F#unctional Londoners Meetups", height = 1200)

let activity=

    [for e in events -> e.LocalDate, 1] |> Chart.Calendar |> Chart.WithOptions options



The white squares indicate a meetup event:


Looking at the data, we can see there’s been a meetup almost every month since the group started back in 2010, and back in April 2016 we managed 5 events in just one month!

We can also see that there’s been slightly less meetups over the last year and a half. This roughly coincides with the fact that I stopped working in London in early 2016. To this end, if somebody who is interested in F# AND lives or works in London would like to get involved in organizing the group, then please do get in touch.

That said the show will still go on (just a little less frequently), and we have a meetup scheduled this week on Thursday 7th December with Jorge Gueorguiev Garcia on Functional Calisthenics, so please do register and come along.

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