STEM has its own terminology for internal references, similar to the labels used in the dialogs, but generally rather more compact. You can type references to other fields straight into the formula bar, but it is usually easier to use the point-and-click approach, described above, to generate the reference text automatically.
An internal reference consists of two parts. The first part is the name of the model element which contains the field to be referenced. The second part is a series of labels, separated by dots, identifying the particular field in that element. The full internal reference for the Capital Cost in Resource Transceiver in the example above is:
Transceiver.Costs.Capital
However, in the formula above only Capital
was required to identify the field, because the formula defined a field in the same element, and in the same Costs group of fields.
When the name of an element in an internal reference includes spaces, or any other special characters that might be mis-interpreted as another part of the formula, the name must be enclosed in double quotes. So for a Resource called
Resource 1, the corresponding internal reference would be:
"Resource 1".Costs.Capital
If the name of an element actually contains a literal double quote, this must be escaped with (preceded by) a ‘~’ character, and therefore the ‘~’ character must also be escaped. Thus for a Resource with the unlikely name,
xx"yy~zz, we would have:
"xx~"yy~~zz".Costs.Capital