Discrete always provides discrete, or individual values, listed out. Continuous will provide a range of values. This is illustrated in your screenshots, where discrete pills give discrete headers for each individual item, and the continuous version of the same pill provides a range of values instead.
The links above should make it very clear. This is a VERY critical Tableau concept, so its good that you are asking this question now! Cheers.
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This is the article that led me to the answers you're looking for:
And here is the article that article points you to:
I included both because the first one was very valuable to me in conjunction with the answer to your original question.
Yep, the 5 things article was one I was looking for too--thanks for adding Robert!
I think we replied at the same time. I always try to refresh to make sure I'm not jumping another answer but I guess it doesn't always work
I hear ya, it happens a lot--I wouldn't worry about it much, the more experience and knowledge within a thread, the better.
Thanks for the links. I am going to read (or re-read) all that stuff.
FWIW, you saying
"discrete pills give discrete headers for each individual item, and the continuous version of the same pill provides a range of values instead"
Makes more sense to me than
Discrete fields always result in headers being drawn whenever they are placed on the Rows or Columns shelves. Continuous fields always result in axes when you add them to the view.
That alone was worth the price of admission. Cheers. (I'll be back)
Obvious question number one: From the Data roles: Continuous vs. Discrete link here is the quote: "Both examples show the Sum of Margin as a function of Inventory level. It is the same information presented in two different ways." These images look drastically different to me.
These two images do not appear to present the same information. This investigation prompted me to look closer and I think I see one of the things that has thrown me off. The two visualizations do not show the same information. The line chart shows a lot more information that the bar chart. In these screen grabs I have highlighted approximately what I think I am seeing. The yellow box represents the information shown in the bar chart. Do you concur that I am identifying this information correctly?
I'm not sure what you mean--the negative values are also in the Discrete version of the chart--you would be much more likely to use the Continous version, since its much easier to understand this particular dataset displayed across a range of values on an axis rather than each discrete individual value as an Axis label. That is where the original description of "drawing discrete headers" versus an "Axis range" comes into play.
The bar chart is listing each discrete value from the measure as an axis "header". The line chart is showing a continous line, over a range of values on the axis. But it IS the same data, displayed two very different ways. You can verify this by exporting the underlying data--it will be identical in both views.
But yes, its the same information, encoded two different ways. Does that make sense?
I would imagine you haven't had time to go through all those links... I believe they will help you understand the differences. There are many differences between discrete and continuous (as well as dimensions versus measures--remember, Blue means discrete, not a dimension, and green means continuous, not necessarily a measure), and they impact visualizations and Tableau behavior in major ways.
Cheers, and I hope this helps! If not, I'll step out and let someone else try their hand at explaining. But I do think the links provided do a pretty good job of it overall. It just takes time and practice to understand all the practical implications for Tableau views.
It looks to me that the sample bar chart does not show any negative Sum of Margin values. Nor does it show inventory values greater than positive 36. According to the line chart these are the values that correspond to the negative Margin values. This is why I think data is missing from the bar chart.
The underlying data is not available.
(I think the bar chart needs a horizontal scroll bar, am I the only one who thinks data is missing?)
Yes, obviously there are more values shown in the line chart. But its based on the same data--yes, the bar chart would continue and that is not shown in the screenshot.
The continuous range of values in the line chart also allows for negative sum(Margin) values. In the discrete version, the chart starts at 0, so this information doesn't get included. I'm not sure if that is by error, or if they just set the axis to start at 0, and data was removed as a result.
Feel free to contact firstname.lastname@example.org're certainly right that there should be negative sum(Margin) values in addition to negative Inventory values.
However, the area you highlighted in yellow in the picture IS shown in both charts--that is showing the range of negative inventory values.
Another thing to keep in mind is that they have used two different view/chart types to differentiate the data roles, which may also be confusing to some users. One is a bar chart, and the other a line chart, obviously. With line charts, we have more options and that can be another factor.
My guess is they were using a sheet when they took the screenshot, so a scrollbar wasn't added. I understand your confusion now--those bars would continue into negative margin territory.
Here's an example I just quickly built--on the sheet, you can see the negative values on the bar chart. When placed in a dashboard, a scroll bar appears. No matter how small you make the sheet, no scroll bar. I'd imagine that's all it is.
Hopefully, this has helped and not hurt, your understanding of discrete versus continuous.
All great questions, and I would agree that the documentation is confusing (in general, this is true--that's why I highly recommend blogs like Jonathan Drummey's and this Forum, where you can get far greater detail about Tableau and how to utilize it for your own purposes--rather than pre-cleansed, flat-file data sources)
Sheet versus Dashboard.twbx 8.8 KB