Trend lines predict future values based on historical data. In this video, learn how to add a trend line to a chart.
- Creating tableau visualizations, lets you discover important information about your business. For example, if you want to see how your business has changed over time, you can create a line chart. You can also add a trend line, which draws a single line that best describes your best performance to date, and can also be used for a forecast. In this movie, I will show you how to add a trend line to a line chart visualization, my sample file is 11_04TrendLine and you can find it in the chapter 11 folder of your exercise files collection. In this workbook, I have a line graph, or line chart, that shows sales by quarter. If I want Tableau to calculate and display a trend line, in other words, the line of best fit, through my existing data, then I can go to the analytics tab, over near the navigation area, and then under model, I can drag trend line onto the visualization. I have a number of options available to me, the ones that I can use depend on my data set. In this case, I have just quarter, and then a single value field, so I can do linear overtime, I can do exponential, or polynomial. Unless, you know otherwise, you should always use linear as your trend line. Exponential and polynomial tend to be used in scientific applications. But in business, if you're just looking at sales datas, in this case, linear is what you want. So I will drag the trend line pill to linear, and you'll see that the trend line has been added. This is the line of best fit through the existing data, and you can also see, that it extends beyond quarter number 3. When I move the mouse pointer over the trendline, you can see that a tool tip appears, and it shows the equation for the line, which is 403.158 times the quarter, that is the count of the quarter, and then it looks like it's minus a very small amount. The r squared value is the amount of variation, or the amount of the value that is explained by the model, and 0.16247 is pretty low, so this trend line doesn't explain the data very well, so we need to take that into account when we look at any future projections. The p value is another measure of how good our model works to explain the data, and 0.282 is not that great. Generally, you want to have values below 0.05 or even better, 0.01. With the trend line in place, you can right click it, so right click here, and then you can click edit all trend lines. In the trend line options dialog box you can change the model type, in this case we'll stay with linear, and then below, the only option that isn't selected is show confidence bands. The confidence bands represent a confidence interval and that could be the range of values where, according to the math of the model, the actual values will fall within the top and bottom part of the confidence band with, say, 95 percent accuracy. If you want to show the confidence bands, you can check the show confidence bands box, click okay, and there they appear. And you can see that the bands are curved, so they go further out as you go along, and also there's quite a wide spread. So, we have several hundred thousand dollars above and below the mean, above and below the trend line, so that tells us that, in fact, this line doesn't fit the data very well. You can also edit the trend line, to change its appearance, so if I right click the trend line, I can click format and then over in the navigation panel I get format lines, and I have trend line here, so if I click that I can change the style, change it's color. So, for example, if I want to make it orange, I can click that, click in the body of the vis, and there they are. When I'm done formatting lines, I can click that panels close button, and continue working with my data. If you want to hide your trend line, you can right click it and click show trend line, which is currently selected, when you click it, it's turned off, and you're back with your graph the way it was before.
- Explain where a user would navigate to seek specific help in Tableau.
- Determine the best approach for using Excel in Tableau.
- Interpret how to use the features and functions of Tableau when creating charts.
- Describe how best to manage data in a worksheet or visualization.
- Explain how to create a selection filter for certain values.
- Explain how to manage data for different chart formats.
Skill Level Beginner
1. Introducing Tableau
2. Managing Data Sources and Visualizations
3. Managing Tableau Worksheets and Workbooks
4. Creating Custom Calculations and Fields
5. Analyzing Data
6. Sorting and Filtering Tableau Data
7. Defining Groups and Sets
8. Creating and Pivoting Crosstabs
9. Creating Basic Visualizations
10. Formatting Tableau Visualizations
11. Annotating and Formatting Visualizations
12. Mapping Geographic Data
13. Creating Dashboards and Actions
Next steps1m 17s
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.