The Data School Blog

How to build a linear trendline for calculations

How to build a linear trendline for calculations

One of the analytical features that Tableau offers is the capability to build a trendline with just a couple of clicks. However, trendlines in Tableau do have some limitations, among them is that you can’t use them within your calculations. This becomes especially troublesome if, for example, you want to calculate the distance to the trendline or do any other calculation that interacts with the trendline.

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How to make a correlation matrix in Tableau

How to make a correlation matrix in Tableau

A correlation matrix is handy for summarising and visualising the strength of relationships between continuous variables. Essentially, a correlation matrix is a grid of values that quantify the association between every possible pair of variables that you want to...

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Successful Data School Client Projects

Successful Data School Client Projects

During our time at the Data School, we have about 8, week-long client projects. We get the brief and data on a Monday and then have to present our findings on the Friday afternoon. After presenting we then have a feedback session with the coaches and hopefully improve...

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The Prep Off: Alteryx vs Tableau Prep Round 2

The Prep Off: Alteryx vs Tableau Prep Round 2

Two major contenders in the ring tonight: new but developing at light speed, Tableau Prep and tried and trusted, Alteryx Designer.Who will win this time after a draw in the last Prep Off? Watch the replay of Round 1 here. How do these two softwares compare when...

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Set Actions Practice Tasks Answers

Set Actions Practice Tasks Answers

This blog provides the answers to the Tableau set action tasks found here. Proportional Highlighting Create the two sheets, segment by sales and sub-category by sales.Right click the segment dimension and create a set.Place the segment set on the colour card in the...

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Set Actions Practice Tasks

Set Actions Practice Tasks

Tableau's set actions allow you to make your dashboard or worksheet interactive. By hovering, clicking and generally interacting with the elements on a sheet colours, sizes marks and may more things can be influenced on both the same and other charts. Set actions...

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Are you sure you need a dual-axis?

Are you sure you need a dual-axis?

Let’s say that you wanted to have two measure values on one graph and to colour by these measures as well as have lines with different thickness. Prior to last week I thought it would be necessary to use a dual-axis chart for this which was a frustration as this means...

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Tableau’s Order of Operations

Tableau’s Order of Operations

Order of Operations To understand how Tableau works it is useful to know the order in which it manipulates and filters data when producing your view. This process is called the order of operations. It helps to know the order of operations so you can use it to your...

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Colouring using a Parameter

Colouring using a Parameter

In this blog post I will be talking through the steps to making a line chart in which the colour of the line is controlled by a parameter. This can be useful when you want to show all values for context but don't want too many colours and feel a different colour would...

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Tableau Dateparts vs Datevalues

Tableau Dateparts vs Datevalues

Dates in Tableau will behave differently depending on whether they are a datepart (blue) or a datevalue (green). This affects how the axes display/behave and also how visualisations such as line charts will display. The difference essentially boils down to dateparts...

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Why You Should Apply For The Data School

Why You Should Apply For The Data School

Now that DS11 are approaching the end of our 4 months of training at the Data School and will soon be shipped off to our first of 4 placements, I have been reflecting on the experience and would like to convince you to apply for the Data School too.   Because...

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Dashboard Formatting With Containers in Tableau

Dashboard Formatting With Containers in Tableau

Before joining the Data School dashboard formatting was a nightmare. I thought that the sizing and position of things relied on the eye alone and would spent ages resizing things and trying to make them align in an aesthetically pleasing way. Since learning about...

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My Project Manager Experience

My Project Manager Experience

PROJECT MANAGER (PM) EXPERIENCE AND TIPS FOR FUTURE DATA SCHOOLERS   On my 7th week at the Data School, I was Project Manager for DS12. It was DS12's second client project for MOO Business Services (MBS). The total time that DS12 were given during that week for...

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Alteryx Core Exam Tips

Alteryx Core Exam Tips

The Alteryx Core exam is a very good way to test your Alteryx skills and also learn some new information that would usually be glossed over. The exam can be registered for here and at the start of the next month you will receive an email with a link that allows you to...

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Tableau QA Revision Tips

Tableau QA Revision Tips

Tableau QA Exam Tips The Tableau QA Exam can be a little intimidating, but there are lots of resources out there from the community and Tableau itself to help you pass the certification. Here I will go through some of the things I found most useful in preparing for...

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Data School Shadow Days

Data School Shadow Days

The Data School not only trains us in Tableau and Alteryx, but also give us a chance to develop other skills like presenting, writing and working with clients. In addition to this, in the last month of our DS time ahead of our placements we shadow a member of the...

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Organising your Tableau Data Pane for Bliss and Harmony

Organising your Tableau Data Pane for Bliss and Harmony

Today DS11 and DS12 were treated to a talk from Simon Beaumont about data architecture, enabling customers to understand your dashboards, how to make your workbooks easy for others to pick up and more. In this post, I will go over a few things about organising your...

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Using Alteryx to Append Fields with a Lookup Table

Using Alteryx to Append Fields with a Lookup Table

While attempting the recent NHL Makeover Monday, I decided to supplement the attendance data with stadium capacity data. I found some data that would work and after some quick cleaning of the data set, added it to the NHL data on Tableau. I ended up with a lot of null...

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Tableau’s ‘Replace References’ feature

Tableau’s ‘Replace References’ feature

I feel an urgent need to blog about a simple feature in Tableau that just potentially saved me from hours of retrospective code-amending and checking. My almost nightmare Let me start with some context. I've spent the last few days exploring a dataset in Tableau and...

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Structuring Word Clouds

Structuring Word Clouds

Word clouds don't have the best rep, but they can be a powerful tool to represent text-based data. There are tons of great manuals for how to build a word cloud in Tableau, so I won't get into the details about that here. One thing I will say is that with word clouds,...

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How to Prepare for your Alteryx Designer Core Exam

How to Prepare for your Alteryx Designer Core Exam

This month, many of DS11 are taking the Alteryx Designer Core Exam (as well as the Tableau QA), including myself. If you're interested in my top tips on how to pass the Tableau QA, see my post here  In this post, I will go through: The resources I found helpful while...

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How to Teach Tableau/Alteryx : Louise’s Experience

How to Teach Tableau/Alteryx : Louise’s Experience

Last month, DS11 taught the public Tableau and Alteryx and this month, we are conducting webinars teaching the same content. Check out our meetup page for more details on upcoming webinars and events! For both of these lessons, I taught Alteryx Data Prep. If you...

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Diego’s journal (DS12) – Week Four

Diego’s journal (DS12) – Week Four

The week went very fast and it felt a bit like those small recap episodes between the seasons of a TV program. However, it was still challenging as we were introduced to Tableau Intermediate and very important concepts such as LODs, Table Calcs and Order of Operations.

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Web Scraping JavaScript Content

Web Scraping JavaScript Content

Introduction Web scraping is an extremely powerful method for obtaining data that is hosted on the web. In its simplest form, web scraping involves accessing the HTML code (the foundational programming language on which websites are built) of a given website, and...

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Running Sum and Moving Average in SQL

Running Sum and Moving Average in SQL

Using Tableau's Superstore as the database, the SQL query: Select [Region], [Order Date], Sum([Sales]) as 'Sales' From superstore Group By Region, [Order Date] ; creates a table with column headers Region, Order Date and Sales, where the Sales is the sum of sales for...

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Colour Conditions in Tableau

Colour Conditions in Tableau

For this topic, I will be using the Makeover Monday ’19 Week 1 NHL dataset.   I had produced a very simple dashboard that compares the Home Attendance and Road Attendance for every NHL team, filtering by each season. The chart shown in my dashboard is a butterfly...

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Line of Best Fit

Line of Best Fit

When you go to the analytics tab and drag the trend line onto your scatterplot Tableau creates a line going through your plots. But what is it doing and what do the figures mean? When plotting a linear trend line Tableau uses the equation y=ax+b In this equation a is...

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Using YoY change to colour shapes on a line chart

Using YoY change to colour shapes on a line chart

The final Makeover Monday of 2018 was on the average annual Christmas spending in the US. All that was provided was the year and the average spend for that year, although it may seem simple, there were many different takes on this as you can see online. For my viz...

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Chaining apps in Alteryx

Chaining apps in Alteryx

I hit a wall in my previous post when trying to dynamically update a drop down interface tool with the field names of a given input dataset. The issue was that if the field names in the incoming dataset were different to the field names of the dataset that I built my...

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My Experience of the Tableau Desktop QA Exam

My Experience of the Tableau Desktop QA Exam

Excitingly, I got to start 2019 as a Tableau Desktop Qualified Associate! I prepped for the exam over Christmas and took it on the morning of New Years Eve. In this post I will take you through how I approached the exam prep, as well as my experience of the exam...

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Tableau Tip // Creating YTD metrics on a KPI Dashboard

Tableau Tip // Creating YTD metrics on a KPI Dashboard

Using Key Performance Indicators (KPIs) in a dashboard are a great way to give a quick indication of how an organisation is doing. This would be actual number of say sales, or number of people donating to a charity, as well as how these metrics change over time....

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Why Colours Matter

Why Colours Matter

Using colour in your viz adds another dimension that can ascend your dashboard from average to amazing or burn your audience’s retinas. Colour allows you to direct your audience’s attention or gloss over background information. It can be used to invoke emotion, set a...

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Tableau : Behind the scenes

Tableau : Behind the scenes

Using Tableau on a regular basis, dragging and dropping pills all around, we easily forget that is it not as simple and what the machine does behind the scene. 

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Tableau Tip: Watch Out for Misleading Average Lines!

Tableau Tip: Watch Out for Misleading Average Lines!

Tableau's Analytics pane allows you to slap an average line onto your view. Drag, drop, done? Not quite. In this blog, I will show you an example of when the average line Tableau creates for you may not be doing what you think it does.   Let's start So Figure 1...

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Dynamically Controlled Bins

Dynamically Controlled Bins

When we work with data, our continuous data (such as sales or profit) it is usually grouped under some categorical field. Normally these fields would be our discrete variables in the data set, such as “Country” or “Category”. Nevertheless, sometimes we would like to group our data under numerical ranges, this is when we would create a bin based in a numeric dimension. 

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Calculating Amount of Days from First Entry

Calculating Amount of Days from First Entry

In this blog we will use an LOD to calculate the first entry date of purchase of products in the Superstore data set and then use this LOD to calculate the running sum of sales over amount of days after the first sale. This normalises the start of selling for...

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Using LODs to Calculate Customer Retention

Using LODs to Calculate Customer Retention

This post looks at how we can display what percentage of customers is made up of return customers, and what percentage is new customers. To achieve this, I'm using Level of Detail expressions to essentially create bins of customers, depending on when they placed their...

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Tableau MIN(Date) LOD’s – Use Cases

Tableau MIN(Date) LOD’s – Use Cases

Tableau LOD's can be used to get the date of first purchase, first signed up, first order etc. This has many real world applications such as tracking percentage difference from this first date, looking at customer retention from first date and seeing how long it...

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Louise’s 2018 in Data

Louise’s 2018 in Data

This time last year, I was a final year Medical Engineering student without a clear career path. Now, I've graduated and I have a job that I love - more than I expected to have by this time!     2018 has been an amazing year and I'd like to take a moment to...

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Web Scraping 101: A short introduction

Web Scraping 101: A short introduction

What is web-scraping? Web-scraping is the automated collection of information from webpages.   The authors of “Automated Collection with R. A Practical Guide to Webscraping and Text Mining” explain the process very clearly: “The Web consists predominantly of...

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Common Baseline Graph With Parameter (Part 2)

Common Baseline Graph With Parameter (Part 2)

In the first step, I have shown how to create a common baseline graph. Here I will show you how to use parameters to make this graph more dynamic. We will use a parameter control to highlight a chosen subcategory and create a dual axis which will create a large...

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Creating a Common Baseline Chart (Part 1)

Creating a Common Baseline Chart (Part 1)

A common baseline chart will allow you to create a view which will show each dimension starting at the same time to compare their overall trend. From each product’s beginning to end. For example, you could use this chart if you wanted to see how much each product has...

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2018 Data Reflections

2018 Data Reflections

  2018 has been a big year for me, data wise, so I thought it was apt to reflect back before moving forward with some goals into 2019. This seemed especially relevant today, given that I've just passed the Tableau QA Exam! Like my half way through blog, this will...

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Diego’s journal (DS12) – Week Three

Diego’s journal (DS12) – Week Three

During week three we went back to ETL, starting with a deep dive in Tableau Prep followed by a very intensive couple of days learning Alteryx Macros. We finished our week with an introduction to statistics in data visualisation and the different tools that Tableau and Alteryx provide to do descriptive and inferential analytics. One of the different things about week three was that we didn’t have any class with our usual coaches (Carl and Andy) but previous Data Schoolers who now work with the Core Team.

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How to create a Gantt Chart in Tableau

How to create a Gantt Chart in Tableau

In this post, I'll take you through how to create a Gantt chart. This is a useful chart that shows the duration of events, e.g. delivery times or hospital wait times. The date field is usually on the column, and then the various dimensions are on the rows. I'll be...

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Tableau: Creating a customer drop-off tracker

Tableau: Creating a customer drop-off tracker

Tracking the rate of your customers' orders so that you can react if a customer appears to be dropping off   A few weeks ago I built a rudimentary customer drop off tracker for a client project and I thought I'd share the technique. It relies on finding the...

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Dashboard Week Finishing Touches

Dashboard Week Finishing Touches

With some time free over Christmas I decided to look over my vizzes from Dashboard week with a fresher pair of eyes and fix some things that were annoying me. New York City Snowploughs Day ones snow ploughing dashboard was my least favourite of the week and I didn't...

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Dashboard Week Day 5: Boy Bands

Dashboard Week Day 5: Boy Bands

For Dashboard week day 5 we were given a dataset on boy bands. The data contained the highest charting single, dated when it charted highest, for every boy band. It also contained information about every boy band member such as height, hair style and hair colour. We...

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Adding Test Conditions to a Standard Macro

One of the topics covered by DS12 this week has been macros which included learning the difference between standard, iterative and batch macros. We also briefly delved into the world of apps. I wouldn't really consider myself the most tech-savvy person so finding out...

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Dashboard Week – A Summary

Dashboard Week – A Summary

It is the start of the week after dashboard week, this new week is one of festive joy rather than anticipation for what curve balls Andy could throw at us. During these moments of calm, I wanted to reflect on what I have learnt from last week's madness. The week...

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Tableau Tip: Stop Your Viz In Tooltips From Being Filtered

Tableau Tip: Stop Your Viz In Tooltips From Being Filtered

For Dashboard Week Day 4, we looked at Seattle cycling data (see my blog here). I decided to incorporate Viz in Tooltips to enhance my infographic (Tableau Public here) and give the reader more context (see Figure 1). Now I don't often use Viz in Tooltips because I've...

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How to make a Dynamic Tooltip

How to make a Dynamic Tooltip

Dynamic Tooltips   For this topic I am looking into the average adjusted inflation gross versus budget for each of the Disney Renaissance films. Link to dataset.   A dynamic tooltip provides Tableau users a little more flexibility in what they would like to...

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DS11 Dashboard Week // Day Five: Boy Bands

DS11 Dashboard Week // Day Five: Boy Bands

The final day of our dashboard week was so fun! We got a cheeky hint from Andy on Thursday evening with a gif featuring the BackStreet Boys.   He then announced, via his blog of course, that we were to analyse data about Boy Bands from the Internet Boy Band...

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DS11 Dashboard Week Day 5: Boyz Boyz Boyz!

DS11 Dashboard Week Day 5: Boyz Boyz Boyz!

This is going to be a short one since it's been a long week and quite frankly, there is notv all that much to say about what I have created today. Still, it has been a great last day of a long week full of excitement, frustration, satisfaction and tons of lessons...

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DS11 Dashboard Week Day 4: I Want to Ride my…

DS11 Dashboard Week Day 4: I Want to Ride my…

After our excursion into the new, eciting, sometimes confusing, often just plain wierd world of Power BI, we were back in our native Tableau for our second to last Dashboard Week Challenge. This was another data set from the US (it's like nothing interesting ever...

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Dashboard Week Day 4: Seattle Bike Count Summary

Dashboard Week Day 4: Seattle Bike Count Summary

For day 4 of Dashboard week we had to analyse data from Seattle bike counters at various routes through the city. I produced a summary report kind of dashboard which looked into the difference in bike usage between weekdays and the weekend. Bikes were used much more...

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Dashboard Week Day 4 : Seattle, i.e. Cyclist Heaven

Dashboard Week Day 4 : Seattle, i.e. Cyclist Heaven

It's day 4 of dashboard week and I am starting to fatigue. No matter! We push on.   The Challenge Today's dataset counts the number of cyclists riding through the roads of Seattle. Potentially very interesting for a Seattleite (/satellites) or a keen cyclist. For...

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Dashboard Week Day #4

Dashboard Week Day #4

Today Andy set us the task of visualising some data about bike traffic around Seattle. The data comes from about 13 spots around the city where bike traffic is measured. I had a clear idea of what I wanted to achieve in the day. I wanted to make a coxcomb chart, the...

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DS11 Dashboard Week // Day Four: Seattle’s Cyclists

DS11 Dashboard Week // Day Four: Seattle’s Cyclists

Day four's challenge was back in Tableau - analysing count of cyclists from Seattle's Open Gov data. Over the past four or five years Seattle have implemented counters to track the number of cyclists over time in various parts of the city. This is because there are...

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DS 11 Dashboard Week Day 3: I Got the Power

DS 11 Dashboard Week Day 3: I Got the Power

Try Something New! It was hump day for DS11's dashboard week today, reason enough for Andy to mix things up a little and drag us (some of us willingly, some less so) out of our comfort zone. The task for today was to visualise a data set on money paid to US higher...

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Dashboard Week – Day 3

Dashboard Week – Day 3

Today’s task required us to use Power BI for the First time. It only took 15 minutes within using the tool did I become a fan. I find it easy to build different chart types without having to create any complicated calculations (depending on what you want to...

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Dashboard Week Day 3 : Power BI for noobs

Dashboard Week Day 3 : Power BI for noobs

SPOILER ALERT: I like Power BI. Of course it has pros and cons, but overall, not too shabby.     Woah, we're half way there! Woahhhhh! It's day 3 of Dashboard week which means we're at the halfway point! See my viz from yesterday here. Last night, Andy...

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Dashboard Week Day 3 – Using Power BI!

Dashboard Week Day 3 – Using Power BI!

Once again we start our day by presenting our visualisations we made the day before. I was happy to present my radial charts and get a little feedback from Andy about colour and lay out, if you'd like to look over it and give feedback the link is here:...

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A short introduction to Microsoft’s Power BI

A short introduction to Microsoft’s Power BI

Here at the Data school we are habitual Tableau users; hardly a day goes by, including weekends, without opening Tableau at least once, even if only to make a minor tweak or two. I've been here close to 3 months now, and last week ran a brief intro to Tableau training...

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Dashboard Week – Day 2

Dashboard Week – Day 2

For day 2, Andy presented us with very clean data. The data was about police body cam use, in New Orleans. The problem I faced, to begin with, was that I felt that the data was too simple and did not have enough information to create a visualisation with.  So I spent...

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DS 11 Dashboard Week Day 2: I Spy…

DS 11 Dashboard Week Day 2: I Spy…

Today's assignment was to create a dashboard based on metadata about Body Camera usage in the New Orleans Police Department. The data consists of one entry per recording that was uploaded to the NOPD's archives, with time stamps for when the recording was started, how...

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Dashboard Week Day 2: New Orleans Police Body-Cam Usage

Dashboard Week Day 2: New Orleans Police Body-Cam Usage

For our second day of Dashboard week we were given the task of visualising the New Orleans police body-cam data set. There was minimal data prep required but the data itself was limited. It only contained when, where and for how long each recording took place (and the...

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Dashboard Week – Day 2 : Everyone Loves a Pretty Map

Dashboard Week – Day 2 : Everyone Loves a Pretty Map

My first day of Dashboard Week! Yesterday the rest of DS11 enjoyed vizzing >200M rows of data about snow ploughing while I watched from home (hurray for a coincidental day of annual leave).   The Challenge This morning I was rested and ready to take on the...

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Diego’s journal (DS12) – Week Two

Diego’s journal (DS12) – Week Two

Week 2 was all about data visualisation. We learnt about how the brain responds to visualisation cues, explored techniques to build a good infographic and then moved into working with Tableau and Big Data.

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