Strange behavior of FOR loop for real iterator.

konstantin_shiriazdanov

in this simple test feature i reproduced the sutuatuin when number of iterations
of my loop is +2 bigger then one would expect for test values bigger then 127 degrees
https://cad.onshape.com/documents/c0429467b6e5c445825d5e38/w/4ac0768c5fbd908e4dd309f6/e/d53b7f0578bcaaa9835d8461

FeatureScript 559;
import(path : "onshape/std/geometry.fs", version : "559.0");

annotation { "Feature Type Name" : "My Feature" }
export const myFeature = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        annotation { "Name" : "My Angle" }
        isAngle(definition.myAngle, ANGLE_360_BOUNDS);

    }
    {
        var list = [];
        for (var phi = 0 * degree; phi < definition.myAngle; phi += 1 * degree)
        {
            list = append(list, phi);
        }

        list = append(list, list[0]);
        debug(context, size(list));
    });

ilya_baran

I didn't check, but I expect you're running into floating point tolerance issues -- keep in mind that addition is not an exact operation and neither is multiplication by degree (since our internal units are radians).  To fix this, I suggest you either add or subtract TOLERANCE.zeroAngle * radian to definition.myAngle (depending on whether you want inclusion or exclusion).

konstantin_shiriazdanov

thanks @ilya_baran, i suspected it was because real iterator, but hardly belived that it can add two more iterations after only 127

ilya_baran

It's only adding one more iteration: the result of adding 1 degree 127 times is very slightly less than 127 * degree.

MBartlett21

@konstantin_shiriazdanov
Would it fix it if you divided by degree before doing the for loop?

konstantin_shiriazdanov

mbartlett21 said:

Would it fix it if you divided by degree before doing the for loop?

@mbartlett21 possibly if i had unitless integer iterator and multiplied it by degree inside the loop it would work without taking tolerances into account. don't think dividing by real number would help for it

john_f_carr

The FeatureScript range() function may help you.  It divides a range into equal steps and ensures the last value is equal to the upper limit.