How do I make the IsNonNegativeInteger precondition commit?

peter_morris

Hi, I'm learning FeatureScript and CAD generally so perhaps I'm trying to do too much, but I'm comfortable with the basics of CAD and have some competent (in my view!) drawings.  I want to add the ability to create a helical gear and believe FeatureScript is the best way do so.  I've completed the tutorials, but as soon as I try to get started on the preconditions I've failed!  The code below is as far as I've got, and the particular line that is causing the problem is that around the IsNonNegativeInteger.  If I use the IsInteger snippet it works fine, but I would prefer either IsNonNegativeInteger or IsPositiveInteger, but I cant get either to work.  Any ideas gratefully received.

</code><code><pre class="CodeBlock"><code>import(path : "onshape/std/geometry.fs", version : "464.0");<br><br><br>annotation { "Feature Type Name" : "MyGear" }<br>export const MyGear = defineFeature(function(context is Context, id is Id, definition is map)<br>    precondition<br>    {<br>        annotation { "Name" : "Pitch Diameter" }<br>        isLength(definition.pitchDiameter, LENGTH_BOUNDS);<br>        <br>        annotation { "Name" : "Gear Module?" }<br>        definition.gearModule is boolean;<br>        <br>        annotation { "Name" : "Number of Teeth:" }<br>        isNonNegativeInteger(definition.numTeeth);<br><br>        <br>    }<br>    {<br>        // Define the function's action<br>    });
/FeatureScript 464;

kevin_o_toole_1

Great to hear.

You were likely looking at the generated code which comprises a Part Studio — That stuff can be very hard to read!

For future readers, if you want to create a modified version of an existing custom feature, the thing to do is copy the document and modify the code in the Feature Studio.

Best of luck to you, and continue posting in the forums if and when you run into issues!

kevin_o_toole_1

For this the thing to do is:

isInteger(definition.numTeeth, POSITIVE_COUNT_BOUNDS);

For more details I'd look at the predicates and bounds exported from the valueBounds module.

Additional advice: If you want to make a helical gear feature, you could start with a copy of the Spur gear feature, remove the extrude, make a second profile,  and loft between them.

peter_morris

Hi Kevin,

Many thanks for the prompt reply.  The solution you've proposed is what I have now implemented and created my own bounds statement.  I had imagined that I could use the isNonNegativeInteger() in the same manner as isInteger(), the only documentary difference is that against the latter form it does state that it can be used as a Feature Precondition, whereas this is not stated against isNonNegativeInteger(), which is not very easy for anyone learning FeatureScript.  Perhaps improvements in the documentation in this area could be considered for the future?

With regard to the latter suggestion, I did consider trying to amend the Spur Gear Feature and may well need to resort to that as a solutio, but I hope I will learn more by starting from basics! - I'm already learning a lot!!

Again, many thanks

Peter

peter_morris

Hi Kevin,

Apologies, but further to my last post I thought I'd look at the Spur Gear Feature, unfortunately I don't seem to be able to access the code.  I've created a spur gear in a parts studio, but when viewing the code I can't make any sense of it.  It appears to have long hashed names and a structure that doesnt reflect anything in the tutorials. A segment of it is shown below.  What am I doing wrong?

const buildPrivate = definePartStudio(function(context is Context, configuration is map, lookup is function)
    precondition
    {
    }
    {
        const id is Id = newId();
        annotation { 'unused' : true }
        var features = {};
        features.F95ADTdmMwyvnvg_0 = function(id)
            {
                annotation { 'unused' : true }
                var features = features;
                if (true)
                {
                    {
                    }
                    annotation { "Feature Name" : "Spur Gear (#teeth teeth)" }
                    d5742c8cde4b06c68b362d748::vc65839fc6078faeb4d2aece1::e01a666571e625f8b819fd75b::me0006d76c0ec7692c3393bb7::SpurGear(context, id + "F95ADTdmMwyvnvg_0", { "teeth" : "25", "numTeeth" : 25.0, "GearInputType" : d5742c8cde4b06c68b362d748::vc65839fc6078faeb4d2aece1::e01a666571e625f8b819fd75b::me0006d76c0ec7692c3393bb7::GearInputType.module, "module" : 1.0 * millimeter, "diametralPitch" : { 'value' : try(25.400000000000002), 'expression' : "25.400000000000002" }.value, "circularPitch" : 3.141592653589793 * millimeter, "pitchCircleDiameter" : 25.0 * millimeter, "pressureAngle" : 20.0 * degree, "centerHole" : false, "centerHoleDia" : 10.0 * millimeter, "key" : false, "keyWidth" : 3.0 * millimeter, "keyHeight" : 3.0 * millimeter, "centerPoint" : false, "center" : qUnion([]), "gearDepth" : 5.0 * millimeter, "flipGear" : false, "offset" : false, "offsetClearance" : 0.0 * millimeter, "offsetDiameter" : 0.0 * millimeter, "offsetAngle" : 0.0 * degree });
                }
            };
        try(features.F95ADTdmMwyvnvg_0(id));
        return context;
    }, millimeter, {});

peter_morris

Kevin, Please ignore my most recent post - I've found the version to copy!! sorry.

kevin_o_toole_1

Great to hear.

You were likely looking at the generated code which comprises a Part Studio — That stuff can be very hard to read!

For future readers, if you want to create a modified version of an existing custom feature, the thing to do is copy the document and modify the code in the Feature Studio.

Best of luck to you, and continue posting in the forums if and when you run into issues!