Graphics Programs Reference
In-Depth Information
Size>250mm,″Neck Size is too Big “Neck Size is
Correct”)
The next two types of statements (Logical and/or) are good for testing
whether a diffuser has been sized correctly. Either of the following formulas
could be used:
Using Logical
and
If(and(Air Flow>Minimum Air Flow, Air
Flow<Maximum Air Flow),“Correct”, “Wrong Size”)
Using Logical
or
If(or(Air Flow<Minimum Air Flow, Air
Flow>Maximum Air Flow),“Wrong Size”, “Correct”)
Both of the preceding statements give the result—a text string—stating
whether a connection is correctly sized…or not.
Using Logical
not
if(not(Top Alignment), 0″, tan(15$) *
b)
Using Logical
not
for Yes/No Parameters
not(myCheckbox)
Using
if
with Yes/No Condition
If (Length>10)
(Note that both the condition and the results are implied.)
Embedded
if
Statement with Logical
and
if(and(Maximum
Air Flow < 391 CFM, Auto Size), 8″, if(and(Maximum
Air Flow < 641 CFM, Auto Size), 10″, if(and(Maximum
Air Flow < 1001 CFM, Auto Size), 12 1/2″,
if(and(Maximum Air Flow < 1651 CFM, Auto Size), 15″,
if(and(Maximum Air Flow < 2201 CFM, Auto Size), 17
1/2″, if(and(Maximum Air Flow < 3001 CFM, Auto Size),
18″, OVERRIDE HEIGHT)))))if(and(Maximum Air Flow <
185 l/s, Auto Size), 200mm, if(and(Maximum Air Flow <
300 l/s, Auto Size), 250mm, if(and(Maximum Air Flow <
470 l/s, Auto Size), 350mm, if(and(Maximum Air Flow <
780 l/s, Auto Size), 400mm, if(and(Maximum Air Flow <
1000 l/s, Auto Size), 450mm, if(and(Maximum Air Flow
< 1400 l/s, Auto Size), 450mm″, OVERRIDE HEIGHT)))))
Revit can be very picky about the units that you use in formulas. For
example, you can't use the Number parameter in a CFM (l/s) parameter
