Legends

Legends make use of symbology or colours to graphically represent codes or numeric ranges in reports. Legends can therefore be divided into two categories:

• text-based legends (e.g. using codes)
• numeric legends (based on numeric ranges)

A legend comprises two or more bins, where each bin is associated with a given text code or a specified numeric range. Each bin in turn is represented by a colour or a pattern.

Legends can be built in two ways:

• by manually adding the individual bins, one by one
• by using the wizard to generate a number of bins automatically.

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Creating a text legend using the manual method

Code legends are usually created by way of the legend wizard, using the mappings established via the  Code Table Symbology editor xxx. However, it is also possible to create legends based on ad hoc code lists.

Starting with the legends editor, click the Add Legend toolbutton.

In the legend editor, enter a description for the legend. (This example will be a simple legend based on the codes "Yes" and "No".)

Choose the legend type (text-based, for this example).

Click the Add Bin  toolbutton to start adding bins to the legend. This opens the Legend Bin editor.

In the bin editor, enter the code and description for the bin. Select the standard colour radio button and choose the desired colour from the background colour dropdown list.

Click the Save button to save the bin.

Now repeat the process to add the second bin, using the code "N" for "No".

This results in a legend with two bins.

Finally, click the Save button to store the legend definition.

Creating a numeric legend using the manual method

A numeric legend is created in very much the same way, but in this case the legend type is numeric and each bin is associated with a specified numeric range.

Numeric legends are usually created using the legend wizard; however, the manual method is easier when the extent of the numeric range differs from bin to bin.

The following example creates a legend for values based on a base-10 logarithmic scale.

Three more bins are added in similar fashion, resulting in the legend shown below.

Click the Save button to add the legend definition to the list of legends.

Using the wizard to create a text legend

This method relies on mappings established via the  Code Table Symbology editor xxx.

Start by clicking Add Legend in the legends editor.

Enter an appropriate description for the new legend and choose the text option for the legend type; then click the Wizard toolbutton.

Select the appropriate code category in the dropdown list to display the code list, then tick all the codes to be included in the legend. Click Save to generate the legend bins.

Click Save again to create the legend.

Using the wizard to create a numeric legend

The wizard can be used to create a set of legend bins covering a specified numeric range, with each bin represented by a set increment in the value.

Start by clicking Add Legend in the legends editor.

Enter an appropriate description for the new legend and choose the numeric option for the legend type; then click the Wizard toolbutton.

Enter a minimum value and maximum value for the numeric range, as well as the increment value to represent the individual bins. Choose a start and end colour to represent the value range. The colour generated for each bin will be based on the colour gradient between the start and end colours.

Click Save to generate the legend bins.

To modify the properties of a bin (such as description or colour), select the bin in the list and click the Properties toolbutton.

Use the other toolbuttons to add, remove or rearrange the bins.

In the example shown below, appropriate descriptions have been provided, as well as two extra bins to cover extreme values on either end of the temperature range.

Finally, click the Save button to store the new legend in the database