Consider the line graph below, here we have a variety of different coloured lines lines representing the values of various dimensions over a range of dates. These sorts of lines charts are often used to highlight seasonal variation or used to make predictions around future forecasts. They are very useful, and most common when doing any sort of time series analysis. However, I think you'll agree that mostly because of the dimensions as colours, it's a little bit confusing.
Frequently, when looking at data over a set time period, business users might just want to see the overall trend (i.e. are my sales going up over 12 months). To see this quickly and easily, you only really need the start and end points of the time series, also better known as "Slope Charts".
There are two ways to construct a slope chart, the first is the static way, for this way you simply create a line chart, then select all the marks between the maximum and minimum date. Then exclude all these points (see below).
This creates the below slope chart for this one particular view of the data; note how you can easily see the sharp upward trends for the pink and dark green lines (so much easier than the very first chart).
The second way to create a slope chart is the more dynamic way, here we use the following calculated field.
Placing this on the filter shelf and selecting show true, will give us the slope chart:
The advantage of using a dynamic slope chart is of course that when you apply a date filter (or any other filter) to the chart, it will change to reflect the new date range.
Hope #TodaysTableauTip has been useful, and I'd like to thank Andy Cotgreave for the formula that makes these dynamic slope charts possible. Its important to note that I'm not saying that Slope Charts are better than your standard line charts, they both have their place, but in this particular scenario I feel the Slope works better. Do you agree?