Is it possible to change a varible entity

[The Big Bear]

Hi All

I am trying to write a script that calculates the thickness and width of an reinforcement pad.

I have asign one variables with the starting width and another varible with the starting thickness but would like to change the varible entity if they need to be wider and thicker.

This is what I have done so far but it does not quite work.

Set Variable [$dp; Value: Field a + Filed b]

Set Varaible [$te; Value: .375

If[if(area_required > total_area;

A5=($dp*$te);"")]

endif

loop

If[case(area required > total_area;

$dp=($dp + .5) and $te=($te+.125);

A5 = ($dp*$te)]

endif

If[area_required < total_area]

EXIT Script []

endif

endloop

The looping script is where I have the problem. The variables do not change. Is ther a way of having the varible increase until the total area becomes larger than the area required?

I hope I have explain my problem to understand what I am trying to do.

Thanks

Lionel

Edited October 29, 2007 by Guest

[comment]

Can you explain the actual problem (in non-Filemaker terms)? I gather you start with a given width and thickness, and a required area. The rest is a complete mystery.

[The Big Bear]

Comment

Sorry about that.

I want to increase the width and thickness of the reinforcement pad until the total area is greater that the area required.

Example

Thickness is set at .375

width at 2

I want the width varaible to increase by .5 segments and the thickness variable to increase by .125 segments until the total area is greater then the area required.

Hope this explaination helps.

Lionel

[comment]

I'm afraid it's still not very clear. Is the area calculated as width * thickness? And what determines which variable should be increased, and by how much? You can get a variety of results here, all seemingly correct.

My instinct would be to increase both parameters by the same ratio to get the required area, then round them up to the next 'notch'. This could be done by a relatively simple calculation - no looping required. But perhaps you need something else?

[The Big Bear]

comment

You are correct, both variables will be change at the same time. The calculation is width * thickness. the required area will be calculated and will change as the condition change. the thickness variable will be set at 2 inches.

The thickness varaible will be set at .375 inches

If the [color:red]required area is larger than the [color:red]total area then I want the width area to be increase by 1/2 inch and the thickness area by 1/8 inch until the required area is less than the total area and then the script will exit.

Thanks

Lionel

Edited October 30, 2007 by Guest

[comment]

Do I understand this correctly:

You ALWAYS start with an area of 2 * 0.375 = 0.75 sq.inch.

You want to increment BOTH values x times, with each increment adding 0.5 to the width and 0.125 to the thickness, until the required area is reached or exceeded?

[The Big Bear]

comment

That is correct

[comment]

Well, if you want to do this with a script, I think you could do something like:

Set Variable [ $a ; 2 ]

Set Variable [ $b ; 0.375 ]

Loop

Exit Loop If [ $a * $b ≥ RequiredArea ]

Set Variable [ $a ; $a + 0.5 ]

Set Variable [ $b ; $b + 0.125 ]

End Loop

# NOW DO SOMETHING WITH THE VARIABLES

However this seems a bit pedestrian, since x could be computed directly from the formula:

( 0.5*x + 2 ) * ( 0.125*x + 0.375 ) = A

where A is the required area. If I'm not mistaken*, this can be rewritten as:

x^2 + 7*x + 12 - 16*A = 0

and solved as a quadratic equation.

Edited October 30, 2007 by Guest
(*) and of course I was...

[The Big Bear]

comment

I will look end to both ways.

Thanks

Lionel