Formulas In Schedules? [Archive]

Phillip Miller

2003-12-19, 11:34 PM

Hi All

Thanks for your replies. If I understand you correctlly, what you are saying, is that you need a unique family for each window and door in the whole model and assign the lintel to that family.

This seams an odd way of doing things.

In ADT I might have typically only three to five window styles, but all differnt sizes. When I stretch the window automatically the schedule will update with the new lintel size and hold down fixings. This calculation has to assess the size of the window, the loaded dimension on the lintel itself, the type of lintel it is, eg supporting roof, supporting roof and upper walls, supporting roof, upper walls, and floors, and also what wind zone we are in for the hold down fixings. I can't see how you could do this by not using more complicated formula that is supported in Revit.

What you are saying, is that you would have to create a new window style (family) for each window, therefor you might have 30 windows on a job???

Thanks for your reply anyway. I was just curious as to how Revit handles formula. Looks like ADT might be better in this regard.

Cheers

Phillip

hand471037

2003-12-19, 11:51 PM

Phillip, in a word, no. It would be much more like your ADT.

You would have three or four window families, with many family types within.

So, for example, you would have your wood double-hung window family, your casement window family, and your fixed window w/mullions family. Within those three families, you would have different types, which in this case would define the different sizes of that *kind* of window. So you would have, under your project browser:

wood double-hung
- 24" x 24"
- 36" x 24"
- 48" x 24"

If you opened that wood double hung family, and made changes to it, like changed the trim profiles or number of mullions, then reloaded it into your project, it would change every instance of these three different sized wood double hung windows. So you wouldn't need 30 different window styles! It's more of a 'tree' approach; sometimes 'family' within Revit is the same as a 'style' within ADT (and sometimes not- hence the name difference!) . You can also redefine these types on the fly within your project, giving you a window of any size you want, or redefine all windows of a type, so that all windows that were 20" wide can bow be 24" inches wide or something.

And as for your question about the fomulas, what everyone's saying is that rather than having to make a complex if/then schedule that pulls data from the windows and hashes on it, you could have the family itself calc out the info, and then have that as just another perimeter that get's listed on the schedule, that can also be further calc'ed upon. That could also drive the geometery of your lintels via your window/door size. But most of thei would happen automatically from within the family, and wouldn't require any complex programming at all, just a few reference planes and dim strings properly done within the family!

don't just assume because a tool approaches a problem in a different way that it's either wrong or can't do the task. :)

Revit can do a lot with fomula, and have that info drive the geomotry in very complex ways. Just because it doesn't do it using VB statements and custom programming doesn't mean it can't be done! I've made several fomula-driven families, and now with fomulas in schedules, have started making projects that will, say, auto-calculate BOMA load factors and such. Every bit as capable as ADT, with the added bonus of it being much more accessible to the general public.

Now, when it comes to programing and *extending* the product, ADT wins out, for if you can't do something in Revit then there isn't really a way to make a plug-in or add-on that will do what you want. However, there isn't much that Revit can't do at this point, so I feel that the lack of an API is almost moot, except for in certain cases. I don't have to write VB script to do complex things with Word, or write C+ plugins to do complex things with Photoshop either...

JamesVan

2003-12-20, 04:38 AM

.... using If Then Else Statements. If I increase the size of the window the lintel increases automaticlly in line with our building code.

I think I understand where Phillip is coming from. You can establish a formula that is a given multiplier of a value like the width of an opening, but it will react in real-time to any changes in that width.

What PM wants is something that specifies one size of lintel when the width of the opening is within a certain range, then jumps to the next size when it crosses into another range. This would be great not only for lintel sizing, but for horizontal structural elements. Picture a beam family that ratcheted up each standard shape as the length of the beam increased. Another idea is with the unsupported height of walls and the guage of metal stud inside. We have standard partition types that include sub-sets that increase the stud guage within certain ranges of heights.

So to answer his question in the short-term, no, there is no ability to do If-Then calculations in Revit at this time, but the schedule formulas are so powerful I can't even begin to estimate their potential yet.

Phillip Miller

2003-12-20, 06:46 PM

Hi Guys

Thanks Jeffrey for your detailed explaination on how this would be done in Revit. Looks like I will have to download it myself and try it out.

You understand where i'm comming from James. This is the start of my code to how it works FYI:

type = [LType]
Width = [Width]
lDim = [LoadDim]
weight = [Weight]
cladding = [Cladding]

If ltype = 1 Then

If weight = 1 Then

If lDim = 3 Then

If Width <= 1200 Then
RESULT = "100x100"
ElseIf Width <= 1800 Then
RESULT = "150x100"
ElseIf Width <= 2400 Then
RESULT = "200x100"
ElseIf Width <= 3100 Then
RESULT = "250x100"
ElseIf Width <= 3700 Then
RESULT = "300x100"
Else
RESULT = "Note 1"
End If

ElseIf lDim = 4 Then

If Width <= 1100 Then
RESULT = "100x100"
ElseIf Width <= 1700 Then
RESULT = "150x100"
ElseIf Width <= 2200 Then
RESULT = "200x100"
ElseIf Width <= 2800 Then
RESULT = "250x100"
ElseIf Width <= 3400 Then
RESULT = "300x100"
Else
RESULT = "Note 1"
End If .............

See what I mean now. This works really well and I have also made up one for bracing. Now i'm no programmer and as you can see this is resonalbly easy code.

Another thing that frustrated me when trying Revit was the inability to be able to stretch windows and doors with grip editingas in ADT. Is this still the case in R6? What are the advantages of not being able to do this?

Thanks again for your replies.

Cheers

Phillip

PeterJ

2003-12-20, 07:57 PM

The advantage of not allowing grip editing is that Revit's families are common rather than instance based (unless set to behave instance by instance) so altering one window would alter each instance of that type of that family, which may well be undersirable. If you do want to alter all of them you simply change the properties of that type and all instances of it will update.

To take Jeffrey's earlier example you may wish to have an instance of the 24" x 24" wood double hung actually be 26" x 24", so you establish a new type and make it the appropriate size. If however, you wish all instances of the 24 x 24 to be 26 x 24 you simply alter the existing. I don't think any Revit users would se this as limiting in any way.

hand471037

2003-12-20, 08:00 PM

Phillip, I think the reasoning behind not being able to simply stretch the windows ala ADT is because of how Revit uses 'types' for everything, which are subsets of families, and that's how you typically control sizes of simular objects. This is true for most things, from chairs to doors to structural beams; it's a bit different of an approach from ADT, but everything works the same, it's increadably consistant, instead of ADT's more mixed approach. This makes it so that once you learn one, you can use them all. Coming from a long history of AutoCAD use, I can't stress how great it is to now use software that's extremely consistant!

Also part of the thinking behind it is that Revit assumes that most things are prefab, and not custom. Stretching windows around in virtual space is one thing, but the contractor is quickly gonna get angry with you for not using standard windows he can order off-the-shelf. It's the same for furniture and other things; they mostly come in certain sizes. It's only in the minority that people can make them any size they want, so Revit focuses more on the majority of this 'kit of parts' approach. At least that's what I think. :)

If you wanted to, you could make window familes that were sized via instance perimeters rather than type perimeters; then you would be able to size each window completely independantly from the rest while still maintining them all within the same family (or 'style' in ADT thinking). However this still wouldn't give you the grips your after. Certain families based upon instance perimeters will respond to the align tool (which is much much more powerful in Revit than in AutoCAD/ADT) so that they will auto-strech themselves to align with whatever edges you've picked. But I haven't tried this out with windows, only custom worksurfaces in systems furniture...

Phillip Miller

2003-12-20, 08:39 PM

HI Peter and Jeffery.

Thanks again for your replies. I'm impressed that you take the time to explain and answer my questions when i'm a silly old ADT user. I am impressed with alot of features of revit, but at the moment i'm sticking with ADT as it suits me better especially dealing with structural engineers that use it as well. But I thing Revit has a very good future.

One last parting shot:

I have to disagree with your comment jeffery:

"Also part of the thinking behind it is that Revit assumes that most things are prefab, and not custom. Stretching windows around in virtual space is one thing, but the contractor is quickly gonna get angry with you for not using standard windows he can order off-the-shelf."

Maybe thats the case in USA but not here in New Zealand. I'm not wanting to constrain my design to what the computer software and building contractor can do!!! Never mind we are different down here.

Thanks again.

Cheers

Phillip

PeterJ

2003-12-21, 08:10 AM

That's an unecessarily sly dig, Phillip, but it's one that is made at ADT too.

The designer can quit any piece of software if it constrains him and get a specialist to show him a way, use a different piece of software or scrawl it on the back of a fag packet to get the idea across. Few designs that can be achieved cannot be drawn using any of the major CAD or BIM applications and that's as true of Revit as ofADT I imagine

EDIT: For our N. American cousins, a fag packet is a cigarette packet, not what you might have been thinking.

Nic M.

2003-12-21, 02:08 PM

Also part of the thinking behind it is that Revit assumes that most things are prefab, and not custom. Stretching windows around in virtual space is one thing, but the contractor is quickly gonna get angry with you for not using standard windows he can order off-the-shelf. It's the same for furniture and other things; they mostly come in certain sizes. It's only in the minority that people can make them any size they want, so Revit focuses more on the majority of this 'kit of parts' approach. At least that's what I think. :)

This was one of my dissapointments in Revit, the focus on the prefab market. For us 99% of what we design is custom made.
We get arround by using instance parameters in families, and since rel 6.0 we can use them (instance parameters) in formulas and export them to ODBC. So I was a verry happy Revity, it only got better.
Thanks

Scott D Davis

2003-12-21, 03:30 PM

The thing with Revit, is that you can be as pre-fab, or as custom as you want. The idea of not having grips for objects like windows is that it forces you to think a little. What size do I actually want this window to be? It's not just an arbitrary pull of a grip, resulting in a window that has a width dimension of something like 3'-7 23/128". If you actually wanted a window with that dimension, you could do it in Revit, you aren't constrained.

Yes, all Architects/Designers want to be 'free' from the constraints of the contractor and computer. But in reality, if you want the project built within a reasonable budget a building with 36 'standard' size windows is gonna be a heck of a lot cheaper than the same project with 36 custom windows, and no one will be able to tell the difference.

hand471037

2003-12-21, 05:48 PM

"3'-7 23/128"

I once worked with someone who would dim stuff to the closest 1/32nd with no 'slop' space anywhere, and would completely ignore common sizes of things like sheets of plywood, ceiling tiles, or rough lumber.

The contractors would laugh at them, and then build it the 'right' way. :)

Phillip Miller

2003-12-21, 06:43 PM

Hi Jeffery

Opps - I'm sorry I offended you!!! I didn't mean it's only Revit that restricts what we design. I would say all software can do that.

You must be joking though when you suggest people design spaces constrained to sheet sizes of plywood!!! If that is the case in the US we are certainlly different here down under.

Cheers

Phillip

GuyR

2003-12-21, 07:51 PM

Also part of the thinking behind it is that Revit assumes that most things are prefab, and not custom.

The thing with Revit, is that you can be as pre-fab, or as custom as you want.

I have to agree with Phillip here. For almost 100% of the residential work I do in NZ I don't buy windows and doors from catalogs. Practically all residential exterior windows and doors are aluminium framed and custom. There are some standard sizes and layouts I use but I spent a hell of a lot of time building custom families.

If you are going to present 3D information you really need to have 3D content.On a recent renovation project I built nearly 20 windows that were not used in the final scheme. This takes significant time. It's the one feature from ArchiCAD I really miss. Their theometrics door and window builder is the best. Don't get me wrong, I love the family editor but in this part of the world we need a quick way of building doors and windows.

Even window and door families that allow you to place mullions like curtain walls would be a huge improvement.

The bad news Phillip is I've been on about this to Revit since V3 and the standard response in the past has been 'build more content'. The last feedback I had on this 'they are aware of the need but it's a low priority'. I'd suggest firing the request off to the revit team and let them know your thoughts.

Guy

PeterJ

2003-12-21, 09:18 PM

Guy

If you really want to work at it it would be possible to make a family that had a parametric number of mullions and transoms. That way you would need only four families, the 1 mullion 1 transom family, the 1 mullion many transoms, the many mullions and 1 transom and the many by many families.

I haven't had a chance to use 6 yet, but arrays in families in two dimensions, have been troublesome in earlier releases and I think was due to be tightened up. So you should be okay.

To my thoughtful editor earlier on I have been worried to see photos taken by witty friends on their return from parts south showing that the fags on sale in Kings Cross are Peter Jackson....

beegee

2003-12-21, 09:41 PM

To my thoughtful editor earlier on I have been worried to see photos taken by witty friends on their return from parts south showing that the fags on sale in Kings Cross are Peter Jackson....

Apparently you can get them on any street corner. Satisfaction guaranteed.

http://www.zoogdesign.com/forums/phpBB2/download.php?id=1050

GuyR

2003-12-21, 09:42 PM

If you really want to work at it it would be possible to make a family that had a parametric number of mullions and transoms. That way you would need only four families, the 1 mullion 1 transom family, the 1 mullion many transoms, the many mullions and 1 transom and the many by many families.

Believe me Peter I've been working on trying to find a quick way for a longtime now. I use profiles/sweeps and well setup templates currently. I've found I can get the parametric working more reliably this way. This is the closest I've got. It's just not as easy as 4 families. All I can say is have a look at AC's theometric door and window builder and you'll see what I mean.
The family editor is one of the most significant features of Revit but the existing methods of constructing doors and windows don't work well for this part of the world. Now there are a few more voices using revit here people might start believing me:-)

Overall I'm still more productive than I was with AC but it does interrupt the design process when you have to spend even 10 minutes modelling a window or door when it could change 5 times over a day.For initial design studies I find it considerably faster using curtain walls for exterior doors and then putting the 'correct' doors once the clients happy.

Guy

The other problem is revit's so easy to use, functionality that isn't quite there sticks out like a sore thumb.

Guy

beegee

2003-12-21, 09:59 PM

The family editor is one of the most significant features of Revit but the existing methods of constructing doors and windows don't work well for this part of the world. Now there are a few more voices using revit here people might start believing me:-)

Overall I'm still more productive than I was with AC but it does interrupt the design process when you have to spend even 10 minutes modelling a window or door when it could change 5 times over a day.For initial design studies I find it considerably faster using curtain walls for exterior doors and then putting the 'correct' doors once the clients happy.

Guy

Hi Guy,

We use standard and custom doors and windows, depending on which part of Australia the project is in ( ie. North Queensland is custom, South Australia and Victoria are standard )
For the design stage, we just leave the standard windows and doors in usually. The client wouldn't know, since at that stage there are no dimensions or schedules. We swap out the standards to custom when we get into DD.
The customs still usually relate to some module ( Brick, block or metric increments ) so its not that difficult to make the families and reuse them.

You must be working in high end custom residential or commercial, I presume. Even so, I would have thought you could develop a palette of the types you use, together with a type catalogue.

Phillip Miller

2003-12-21, 10:07 PM

Hi Guy

At last someone agrees with me, and you guessed it you are from NZ. As I said we must be different here. Interesting your are using Revit, I've looked a couple of times, but have been a bit concerned about support. How do you find it here. Do you know how many firms use Revit in NZ.

Any way back in ADT I have only four windows set up which basically can do a whole house. I have a single, double even, double uneven, and triple uneven. So basically I insert a window, stretch it to the size I want and maybe I might have to merge a cell or two. Really easy. That was one of the main reasons I stayed with ADT. Same with doors.

This disscussion has certainlly changed from my origonal question hasn't it.

Phillip

GuyR

2003-12-21, 11:16 PM

Beegee,Phillip,

At last someone agrees with me, and you guessed it you are from NZ.

Yep.

You must be working in high end custom residential or commercial, I presume

I wish, almost the opposite actually and mainly residential . Going by recent NZ Architecture magazines if I was doing high-end I'd be exclusively using curtain walls:-)
I don't know if it's just NZ then but from my experience and discussions with fabricators I can certainly save money by specifying same size modules. But different mullion, transom options have minimal effect on cost compared to overall m2 of the unit and pushing extrusion limits (with regard to wind loading etc). That's a simplistic summary, but I find there is little constraint put on custom design with aluminium windows in NZ and it's a very competitive market.

The customs still usually relate to some module ( Brick, block or metric increments )

Perhaps I've misunderstood but to me that's not custom that's parametrics.With regard to type catalogues, often and particularly with doors there is only one type. I do have libraries of windows/doors and often I'm modifiying these to create new ones. All I'm saying is in terms of workflow I'm spending more time than I should be building windows/doors IMO. Particularly compared to the opposition (AC)

Guy

PeterJ

2003-12-21, 11:28 PM

Satisfaction guaranteed.
You've been reading my mail again.

beegee

2003-12-22, 12:11 AM

Perhaps I've misunderstood but to me that's not custom that's parametrics.With regard to type catalogues, often and particularly with doors there is only one type. I do have libraries of windows/doors and often I'm modifiying these to create new ones. All I'm saying is in terms of workflow I'm spending more time than I should be building windows/doors IMO. Particularly compared to the opposition (AC)

Standard windows here would be say 1000x1110; 1000 x 1510; 1000 x 1810, whereas a cutom would be say 1114 x 1090 ( still a brick module, but not available "off the shelf " )
Where the market is larger, they tend to go for standard windows, because they are readily available and in stock. Where the market is small, they dont keep stock and just make them up to order.

GuyR

2003-12-22, 12:29 AM

Thanks for the info Beegee You said it's different depending the state. Why is this? Is it to do with the styles of most houses built?
The reason I ask is I'm about to do the scheme for my brothers house in Mildura.

OT, but have you used hebel blocks? According to my brother they're quite popular in Aussy- his words not mine. He's keen to use them, and they certainly look easy to work with.

I guess the other thing I should say is I don't tend to do a lot of brick work so that probably gives me a lot more design freedom in terms of sizes/shapes.

Guy

aaronrumple

2003-12-22, 02:04 AM

Who said you can't make a window that stretches like in ADT?

You can if the dimension is an instance instead of a type.

The Revit island countertop is a very good example of how an item can be stretched.

However - the designer of the family must decide if the dimension is a "catalog" dimension or a "custom" one.

As mentioned before - soetimes the best place to change aRevit object is in the schedule. Let's see ADT do that....

I make my "schematic" part as instance object for best flexibility during design and then as products are selected - switch families.

beegee

2003-12-22, 02:12 AM

Thanks for the info Beegee You said it's different depending the state. Why is this?

I think its the size of the market.

I'm about to do the scheme for my brothers house in Mildura.

I'm guessing that Mildura would go for standard windows. I'm about to do a project in Griffith, so I'll let you know.

OT, but have you used hebel blocks? According to my brother they're quite popular in Aussy

They do have a following, but its a bit like Mac users :) Personally. I havn't used them. I'd talk to local builders in Mildura first.

I don't tend to do a lot of brick work so that probably gives me a lot more design freedom in terms of sizes/shapes.

Its more about cost than design freedom. If the builder can easily source standard windows and doors in a reasonable size range, its difficult the justify the often substantial cost difference in terms of design.

My 2c anyway.

David Conant

2003-12-22, 05:43 PM

Understanding the Family/Type/Instance hierarchy is a key to making Revit work for you. The structure we have set up is quite intentional (I designed much of it) It attempts to replicate the way things are categorized and accounted for in the real world.
A family represents the entire gamut of components that can be created based on a particular set of governing geometric and logical parameters. It real world metaphor would be a model line, or perhaps several similar model lines such as the XYZ window comapny 123 series windows.
A type represents a particular vairiation of a family's governing parameters. It can be named as desired and identified on schedules or tags. It's real world equivalent is the specific model of a component such as an XYZ window company model 123-24x48.
An instance reperesents the actual placement of a component in a project. It can be identified by type -a 1b window- or by instance -door 325a- by exposing either the Type Mark, or Mark property repectively in a tag or schedule.

We recognize that different components need to be controlled at different levels of this hierarchy. For some, every identified type records a unique and invariant set of parameter values. This is most apt for components that have standard options for manufacture, will be custom sized for this project but used many times over, or where every variation must be uniquely identified for tagging or scheduling. In such a family, all parameters should be type parameters. If a new size is needed, simply create a new type of the desired size.

Other components have variations that are not regarded as creating a new type. A good example is a steel beam where the profile parameters are completely fixed for each type, but the length parameter may vary for each instance. Use instance parameters for such information. These can then be varied interactively for each instance in the project.

The drawbacks to instance parameters are that you lose project wide control over that parameter -it takes more work change an instance value in all instances-, it is much easier for users to create slight variations that would be undesireable in actual construction, and Revit has to track many more graphic symbols thus degrading preformance somewhat.

The content we supply uses as few instance parameters as possible for maximum efficieny. You should evaluate your own usage requirements to determine how to best use them. In most cases, you can open an existing family and change a parameter from type to instance or vice versa as you need.

If there are situations where you cannot get the result you desire, posting here with specific usage examples and pictures will often get you a solution. It will also give us good material to work with as we continue to refine the product.

Have a good holiday. To all you southern hemisphere folks, may it be sunny and warm on the beach. For the rest of us, the shortest day is here, let it snow let it snow let it snow. I'll be off to skiing soon and will be inspecting one of Scott Brown's projects in Steamboat Colorado to be sure he was showing Revit off in a good light. Pix if I don't forget the camera.

irwin

2003-12-22, 08:26 PM

It was mentioned in this thread that you can stretch a window if it has instance parameters. Those of you who haven't done this might try the following:

Load the family "Instance - Fixed" from the standard library. Place an instance of this window in a wall. Go do an elevation view. In the Modify tool move the mouse over any of the four sides of the window. Press TAB until the prompt string says something that ends with "Shape Handle". Click and drag. Note that you can drag the side of the window to get whatever width or height you want.

Other window families can be made to work this way by editing the family and changing some parameters to instance parameters.

Phillip Miller

2003-12-22, 10:01 PM

Hi Irwin

Thanks for your reply. I will have to try it. So when I stretch the window is there any way that in the schedule my lintel size will automatically resize as per our building code, as in ADT.

Cheers Phillip

adegnan

2003-12-23, 01:43 AM

You must be joking though when you suggest people design spaces constrained to sheet sizes of plywood!!! If that is the case in the US we are certainlly different here down under.

No, no, no. Very few of us designers, architects, or contractors actually woud design something to fit exactly to a sheet of plywood. However, much in the tradition of Wright and many others, I generally use a grid system as an organizational method and design tool. I do design to a 4' x 4' grid for material efficiency.

And Revit certainly does not force you to design like that. I stick frame everythign I build. But I do order Andersen windows and I avoid custom sizes unless I'm creating a custom shape. It isn't necessary for me! Using casement windows that vary in width ever 4" and in height every 6" doesn't limit me at all, let along double-hung in 2" increments! Besides that, you can special order to 1/8" if ever necessary. But why pay the premium?

Anyway, Revit can do it all.
Abe, now new & improved with a broken leg.

ita

2003-12-23, 02:45 AM

Hi All,

Fascinating dialog. Thankyou Revit people for the input - I learnt a lot out of that. This is such a valuable forum. The comments and questions provide the depth and subtlety of Revit that is not discernable from the Help or the Tutorials. Thankyou zoog :D

I agree with some of the comments by others, in that the Family "formula" could use boorlean statments. Then Guy could install his lintel sizes related to the NZ building codes - it is the most logical place for that function to occur.

The simple arithmetic formulas are great but can be somewhat limiting if you are used to equivelent spreadsheet instances - it gives some additional flexibility to those (users) who want those attributes - and for the others - being the (probably) most of the people who don't want, it they can ignore it!

On little issue that occurs in family "formulas" is that when you set a ref plane angle to 0degrees the ref plane does not hold its position in relation to the origin. The ref plane shifts!!!

At least you can recover from 0deg in 6.0 - my experience in 5.1 was that there was no recovery.

So Revit masters can we have the ref plane retain its relative pivot point when the subtended angle is zero and when recovering to any new angle?

PeterJ

2003-12-23, 08:18 AM

You can declare an parameter as an integer number then with some care in your formula you can lintel depth = 3" x (integervalue+1) where integer value = width divided by what ever factor affects the lintel sizing. It won't do everything you require but with some care will get you most of the way there.

beegee

2003-12-23, 08:52 AM

Can someone tell me if am integer value in a formula rounds up or down ?

No mention in Help.

I think to get this type of formula to respond properly, you would want it to round up and down. It could work for timber sizes, but I'm nor sure about masonry lintels and suchwhat that don't respond to a linear progression since masonry sizes are more constrained than timber.

PeterJ

2003-12-23, 09:09 AM

Downwards. 3.1 and 3.9 both become 3. The function does not round it just returns the integer portion of a decimal.

I think to get this type of formula to respond properly, you would want it to round up and down. It could work for timber sizes, but I'm nor sure about masonry lintels and suchwhat that don't respond to a linear progression since masonry sizes are more constrained than timber.
I'm not sure that I have it fully worked out, it was offered more as a foundation for someone else to build upon. I have, however, used the integer function succesfully in array situations where I wanted the array number to be parametric dependent on, say, overall width.