Unset Values
- Last UpdatedMar 13, 2024
- 1 minute read
A particular class of undefined values are unset values. The concept exists for attributes which are valid for a given element, but for which no value has been assigned. Typically these may be elements of an array, or ’word’ attributes. References of value =0/0 are also treated as unset.
Unset values are propagated as for undefined values (except for Boolean operations- see below). Undefined values take precedence over unset. There is a specific logical function UNSET to test if a values is unset.
Across comparisons, unset values are not propagated, but are treated as follows:
|
Operator |
When Applied to an UNSET |
|---|---|
|
EQ, GT, GE, LT, LE |
Results in FALSE. |
|
NE |
Results in TRUE. |
|
OR , AND |
Values are treated as FALSE. |
For example, if DESP(2) and LVAL(3) are unset then:
(DESP(2) GT 99) -> False
(DESP(2) NE 33) -> True
(:LVAL(3) AND TRUE) -> False
|
Distance |
Feet & Inch |
Feet & Inch |
Inches |
Inches Denom 4 |
Feet & Inch AVEVA E3D Design |
|
128.5 |
10’-_8_1/2"___ |
10’-_8_1/2"__ |
128.5" |
128_1/2" |
10’08.1/2 |
|
120.0 |
10’-_0"_______ |
10’-_0"______ |
120.0" |
120"____ |
10’00____ |
|
11.5 |
0’-11_1/2"___ |
11_1/2"__ |
11.5" |
11_1/2" |
0’11.1/2 |
|
0.75 |
0’-_0_3/4"___ |
3/4"__ |
0.8" |
3/4" |
0’01____ |
|
0.0 |
0’-_0"_______ |
______ |
0.0" |
____ |
0’00____ |
|
-10.0 |
-0’-10"_______ |
-10"______ |
-10.0" |
-10"____ |
-0’10____ |