Attributes - Defining Constants

To access this dialog:

Using the Setup ribbon, select Model - Attributes - Select the Values tab.
Using the Reserves ribbon, select Mining Blocks - Attributes. Select the Values tab.
Using the Reserves ribbon, select Reserves - Attributes. Select the Values tab.

The Constants panel is used to define re-usable variables for attribute value expressions. The same controls are available using the Model Attributes, Mining Blocks Attributes or Reserves Attributes managed tasks.

Constants represent a fixed expression element that can be re-used over multiple value expressions. Once defined, they can be injected into expressions using the Attribute Value Editor dialog.

Add a constant using New. Constants are described in attribute value expressions in square brackets, e.g.:

Creating a New Constant

You can edit the default name. Then, enter a Value.

A Value can be anything from a simple numeric or alphanumeric constant to a complex expression involving multiple attribute values and other mathematical constructs. In essence, the Value is simply the syntax that will be transposed to the expression whenever the constant is found.

As such, it is ideal for hosting commonly-used calculations that will remain static in multiple situations. For example, calculating a Gold Equivalent grade as (AU*RECOVERY)/100.

Other examples of constants:

A numeric value derived from the numeric attribute MCOST:

MCOST*0.005
A lowercase alphanumeric filename for a reserves table, representing a phase:

lcase(PIT + "_" + PHASE + ".dm")
The sum of multiple named value definitions (as created using the Values tab):

([Named Value 1] + [Named Value 2] + [Named Value 3])/3
Processing cost adjusted to include a Processing Cost Adjustment Factor:

PCOST*PCAF

Once a constant has been defined, it becomes available for any method of attribution (model, mining block or reserves).

Alphanumeric constants should be wrapped in quotes, unless it is a reference to an alphanumeric field, in which case the full attribute name should be given in quotes.

Deleting Constants

You can use Delete to delete a defined constant from the OP database. You will be asked to confirm this action.

Deleting a constant will replace all existing value definitions that use it with the value or expression used to define the constant. This action cannot be undone.

You can delete any existing constant, be aware that any existing expression that uses it will be updated to include the verbose constant expression instead.

For example, if a constant "CuEq" is created as:

(CU/RECOV)*100

...and an Attribute value contains a reference to the constant:

[CuEq]*0.96

...deleting the constant forces the Attribute value to become:

((CU/RECOV)*100)*0.96

The additional brackets are added to the Attribute value(s) automatically to ensure that mathematical operator precedence doesn't introduce unexpected results from the modified expression.

	Related Topics
	The Reserves Workflow Model Attributes Task Mining Block Attributes Task Reserves Attributes Task Attribute Value Editor Dialog Evaluate Reserves Table Summary The Block Outlines File