Creating a master measure from a field
When you are working with an unpublished app, you can create master measures so that they can be reused. You can create a master measure from the Fields section of the assets panel.
When naming an entity, avoid assigning the same name to more than one field, variable, or measure. There is a strict order of precedence for resolving conflicts between entities with identical names. This order is reflected in any objects or contexts in which these entities are used. This order of precedence is as follows:
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Inside an aggregation, a field has precedence over a variable. Measure labels are not relevant in aggregations and are not prioritized.
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Outside an aggregation, a measure label has precedence over a variable, which in turn has precedence over a field name.
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Additionally, outside an aggregation, a measure can be re-used by referencing its label, unless the label is in fact a calculated one. In that situation, the measure drops in significance in order to reduce risk of self-reference, and in this case the name will always be interpreted first as a measure label, second as a field name, and third as a variable name.
- Click to select the fields tab.
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Click the field you want to use to create a measure.
The preview opens.
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Click at the bottom of the preview.
The Create new measure dialog opens with the field you selected. The field name is also used as the name of the measure.
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Click in the Expression field to open the Edit expression dialog.
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Type the expression directly in the expression editor (the main window).
The field names you use in the expression are checked, and the syntax of the expression is validated.
Tip noteAs you type in the expression editor, the expression is validated continuously. If there is an error, you see a hint about what is incorrect in the lower left-hand corner. Additional error information may be available by clicking the icon next to the hint.Each line in the expression editor is numbered and syntax highlighting is used.
Tip noteYou can open the online help with the full description of how to use the current function by double-clicking the function name in the expression editor and pressing Ctrl+H on the keyboard. This feature becomes available after having entered the first parenthesis of the expression after the function name, and only when using a computer with a keyboard. -
Click Apply to close the Add expression dialog.
Now you need to add some descriptive data for the measure.
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Edit the name if you want to.
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Type a description for the measure (optional).
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If you want to specify a color, click in the color drop down and select a color through one of the following methods:
- Click one of the colors in the palette.
- Type a 6 character color code in the Hex input field.
- Click at the bottom of the dialog, select a color in the color wheel, and optionally adjust the saturation slider.
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Add tags (optional).
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Under Number formatting, you can choose:
- Auto
- Number
- Money
- Date
- Duration
- Custom
- Measure expression
- Click Create.
The measure is now saved in the Measures category in the master items, and you can use it in visualizations.
For more information, see Designing visualizations with Direct Discovery.