You can add a reference line, band, distribution, or box and whisker plot to indicate specific values in your visualization. These overlays offer a quick and convenient way to compare multiple data points in a dataset against a central theme and to assess the impact of groups of data points in a single set.

Contents

Lines

Visual Analytics offers a set of reference values based on the underlying data of the user. It indicates values that are average, median, minimum, maximum, sum, or a user-defined constant. You can add a reference line on any axis of a measure or continuous dimension.

 
 
To add reference lines

1. Connect to the sample data source in Aqua Data Studio.
2. Build a Bar Chart.
3. Right-click on the axis, and then click Add Reference Line, Band, or Box.
   
4. In the Add Reference Line, Band, or Box dialog box, select Lines.

5. Choose a scope for the reference lines.

   Add Entire Table	Add Per Pane	Add Per Cell
   Visual Analytics calculates reference lines based on values in the table.	Visual Analytics calculates reference lines based on values in each pane.	Visual Analytics calculates reference lines based on values within each cell.

6. Specify a continuous dimension or measure from the current view as the basis for your reference line. From the adjacent list, select one of the following aggregate functions.
   
   • Sum adds all values in the view and places a reference line of the summed up values in the selected scope.
   • Total places a reference line based on the view's underlying data. It inherits the aggregate calculation from its field. For example, if placed on SUM(Quantity Ordered), Total will calculate the sum of the underlying Quantity Ordered data in the selected scope. If AVG(Quantity Ordered) is used, this results in a weighted rather than simple average of Quantity Ordered. The values obtained via this aggregate function match the result of the Show Row Grand Totals option from the Analysis menu. 
   • Constant places a reference line at the value that you specify in the selected scope.
   • Minimum places a reference line at the minimum value in the selected scope.
   • Maximum places a reference line at the maximum value in the selected scope.
   • Average places a reference line at the average value in the selected scope.
   • Median places a reference line at the median value in the selected scope.

   • Percentile place a reference line at the specified percentile value in the selected scope. Percentile value indicates the percentage of data points less than a given value. For example, if you place a reference at the 75th percentile, 75% of the data lie below that line. 

     All aggregate calculations (except Total) are based on the data in the view as opposed to the underlying data, which means, the calculation is being performed on the chart's visible data points. For these calculations, the view data is binned according to the scope and then the aggregate function is applied. If the user has defined a field calculation, this calculation will be carried out prior to the reference aggregation function. It is treated exactly as view data. Total is not available for calculated functions whose aggregation is AGG().

7. Choose how to label your reference lines from the following options.
   • None does not display any label for the reference line.
   • Value displays an aggregated value for the reference line.
   • Name displays a field name in use for the reference line.
   • Function Name displays an aggregation function name for the reference line.
   • Name-Function displays a field name and applied aggregation.
   • Custom allows creating a custom label. 
8. Choose formatting options for label alignment, line style, thickness, and color. You can also choose to have colors above and below the reference lines.  
   
9. Specify whether to recalculate line based on data selection. For more information, see Recalculate Data with Recalculated Lines.
10. Click Apply and then OK.
    

Bands

Bands are a pair of linked reference lines and provide a range of values for comparison as opposed to a single line. It is often used to determine when a given measure value is exceeding an acceptable threshold. All values that you can use as the basis for reference lines are available for bands as well. You can add a reference band on any axis of a measure or continuous dimension.

To add a band

1. Connect to the sample data source in Aqua Data Studio.
2. Build a Bar Chart.
3. Right-click on the axis, and then click Add Reference Line, Band, or Box.
   
4. In the Add Reference Line, Band, or Box dialog box, select Band.

5. Choose a scope for the band.

   Add Entire Table	Add Per Pane	Add Per Cell
   Visual Analytics calculates reference bands based on values in the table.	Visual Analytics calculates reference bands based on values in each pane.	Visual Analytics calculates reference bands based on values within each cell.

6. Specify a value to use as the basis for your reference band. You can select a value that is part of your current view from the Band From and Band To areas. From the adjacent list, select one of the following aggregate functions.
   
   • Sum adds all values in the view and extends a reference band of the summed up values in the selected scope.
   • Total places a reference band based on the view's underlying data. It inherits the aggregate calculation from its field. For example, if placed on SUM(Quantity Ordered), Total will calculate the sum of the underlying Quantity Ordered data in the selected scope. If AVG(Quantity Ordered) is used, this results in a weighted rather than simple average of Quantity Ordered. The values obtained via this aggregate function match the result of the Show Row Grand Totals option from the Analysis menu. 
   • Constant extends a reference band up to the user specified value, in the selected scope.
   • Minimum extends a reference band up to the minimum value in the selected scope.
   • Maximum extends a reference band up to the maximum value in the selected scope.
   • Average extends a reference band up to the average value in the selected scope.
   • Median extends a reference band up to the median value in the selected scope.
   • Percentile place a reference line at the specified percentile value in the selected scope. Percentile value indicates the percentage of data points less than a given value. For example, if you place a reference at the 75th percentile, 75% of the data lie below that line. 
     

     All aggregate calculations (except Total) are based on the data in the view as opposed to the underlying data, which means, the calculation is being performed on the chart's visible data points. For these calculations, the view data is binned according to the scope and then the aggregate function is applied. If the user has defined a field calculation, this calculation will be carried out prior to the reference aggregation function. It is treated exactly as view data. Total is not available for calculated functions whose aggregation is AGG().

7. Choose how to label the bands from the following options.
   • None does not display any label for the reference band.
   • Value displays an aggregated value for the reference band.
   • Name displays a field name in use for the reference band.
   • Function Name displays an aggregation function name for the reference band.
   • Name-Function displays field name and applied aggregation.
   • Custom allows creating a custom label. 
8. Configure the appearance of the band by selecting label alignment, style, thickness, and color for the lines and shaded area. 
9. 
   
10. Specify whether to recalculate line based on data selection. For more information, see Recalculate Data with Recalculated Lines.
11. Click Apply and then OK.
    

Distributions

Distributions represent variability in a data set concisely. Two sets of identical averages can give a different result if they differ in range and internal variation. Distributions include confidence intervals, percentages, percentiles, quartiles, and standard deviation, and applies shading above, below, and between two aggregated values. You can add a reference distribution on any axis of a measure or continuous dimension.

To add a distribution

1. Connect to the sample data source in Aqua Data Studio.
2. Build a Bar Chart.
3. Right-click on the axis, and then click Add Reference Line, Band, or Box.
   
4. In the Add Reference Line, Band, or Box dialog box, select Distribution.

5. Choose a scope for the distribution.

   Add Entire Table	Add Per Pane	Add Per Cell
   Visual Analytics calculates reference distributions based on values in the table.	Visual Analytics calculates reference distributions based on values in each pane.	Visual Analytics calculates reference distributions based on values within each cell.

6. Specify a value from the following options, to use as the basis for your reference distributions. You can select a value that is part of your current view, from the Value list. 
   
   • Confidence Interval is the estimated range likely to contain values from the mean. It indicates how closely the sampled data reflects the population from which it was taken. 
   • Percentages add shading between the specified percentage values. Separate multiple values with a comma. 
   • Percentiles divide the data set into 100 evenly populated segments. Percentile values indicate the percentage of data points less than a given value. For example, if you place a reference at the 45th percentile, 45% of the data lie below that line. 
   • Quantiles divide the underlying data into a user-defined number of segments, between 3 and 10. The quantile overlay displays all subsets as a series of bands. 
   • Standard Deviation is an explicit measure of the variability of the data. It is shown as a band centered at the mean with a width defined by you.
7. Choose how to label distributions from the following options.
   • None does not display any label for the reference distributions.
   • Value displays an aggregated value for the reference distributions.
   • Name displays a field name in use for the reference distributions.
   • Function Name displays an aggregation function name for the reference distributions.
   • Name-Function displays a field name and applied aggregation.
   • Custom allows creating a custom label. 
8. Choose the formatting options for label alignment, line style, thickness, and color. You can also specify whether to add shading above and below the distribution. Symmetric uses a single color instead of a gradient. Reverse changes the order of the colors above and below the distribution.
   
9. Specify whether to recalculate line based on data selection. For more information, see Recalculate Data with Recalculated Lines.
10. Click Apply and then OK.
    

Box Plot

The box and whisker plot combine a set of reference values into a single overlay. The median, the box plot's center line, is the central value in the data set, with half the points above and half below. The upper and lower quartiles, or upper and lower boxes, further divide the set above and below the median. In this way, we can visualize how closely packed the data are in the upper and lower half of a given set. Not only does the box plot visually divide the data, but it can also indicate which data points fall outside the expected variability of the set (outliers). The outliers are marked by the whiskers in the box and whisker plot. You can choose to include or exclude outliers in the visualization. You can add a boxplot on any axis of a measure or continuous dimension.
 
You can add a box plot by using the Visualization Palette or adding a reference line, band, and box plot option from the axis. In the following example, we are adding the boxplot chart from the Visualization Palette. 
 

To add a box plot

1. Run the desired query in the Query Analyzer and launch Visual Analytics.
2. Select the desired dimensions and measures and then click the Visualization tab, and click . 
   
3. Right-click on the axis, and then click Edit Reference Line, Band, or Box.
   
4. In the Edit Reference Line, Band, or Box dialog box, choose the plot options for the whiskers.
   
   • Data within 1.5 times the IQR  places whiskers at a location that is 1.5 times further out than the width of the adjoining box. 
   • Maximum extent of the data places whiskers at the farthest data point (mark) in the distribution. 
5. Specify whether to hide all marks except those beyond the whiskers.
6. Configure the appearance of the plot by selecting a Style, Fill, Border, and Whiskers.
   
7. Click Apply and then OK.
   

Recalculate Data with Recalculated Lines

If you plot chart using a reference line or distribution and select specific data points in the view, Visual Analytics compares the data for the selected data points and plots a recalculated line for the highlighted data while dimming the original line.
 
The following example originally showed the total quantity of product categories ordered new for each customer segment. Out of these product categories, when you select Office Furnishings from each customer segment, Visual Analytics instantly compares the new quantity ordered for Office Furnishings and plots a recalculated line for the same. Now you can view the total quantity ordered new for Office Furnishing to the overall total quantity ordered new for each customer segment.

Custom Labels

Custom labels allow using multiple label options together along with user specified text. In the Built-in Labels screenshot, we have used Average as the aggregated function for the reference line; however, in the chart view, when the value is displayed, it is difficult to understand the aggregation function in use. This is where custom labels come into the picture. In the Custom Labels screenshot, you can view the aggregated function with its value for the reference line. Custom Label support is available for Lines, Bands, and Distributions.

To create a custom label

1. Open the Edit Reference Line, Band, or Box dialog.
2. Define a scope, a value for the line setting and an aggregation function from the drop-down list to the right of the Value drop-down.
3. In the Label drop-down list, click Custom.
   
4. Click to the right of the text box and click a custom label option. For example, <Function Name>. To add more custom labels, click again.  You can also enter text or enter a value that you want to display on the chart. For example: <Function Name> : <Value>.
   
5. Set the line formatting, and then click Apply > OK.
   

Other Actions

Other actions that you can perform on a plotted charts are as follows:

• You can sort data by using various sort options available in the chart view or the Advanced dialog. For more information, see Sorting.
• You can use highlight actions to focus on selected reference line, band, or box plot. Visual Analytics makes the highlighted lines, bars, and box plots and its data labels prominent while dimming others in the view. For more information, see Highlight Actions.
• You can filter records directly from the chart view without manually adding any fields to the Filters Deck. For more information, see Filters.
• You can export worksheets containing visualization to Image, HTML, and PDF formats. For more information, see Export Visualizations.