Polyline over boundary

Hey everyone!

I'm new to VB.NET and some rather annoying error is keeping me from moving forward with my work.

Here's an example of what i'm trying to do: create a polyline by adding points generated (recursively) by one starting point; if the polyline gets close to a certain boundary (curve), it jumps it.

Simple as it looks, i keep giving an error: "script exception: the index was out of the interval. it has to be not negative and inferior to the size of the collection. Name of the parameter: index"

weird thing #1 - i have no "index" parameter in my code
weird thing #2 - the only list is created inside the script and grows at the same pace as the loop index i have ("i").

Can anyone figure this out?

Thanks!

Attachments:

test_boundary.ghx, 43 KB
test_boundary.3dm, 27 KB

Replies to This Discussion

Permalink Reply by Luis Fraguada on June 17, 2009 at 10:07am

Hello rvzkm,

Why are you incrementing i inside the loop? There is the line:

i = i + 1

on line #74. The for loop does this for you. If you want to increment another variable, make a separate counter. I commented this out, and the polyline jumps over the curve...

When you get this error its because you have reached a point in a list or array where your index (the index value of the element in the array or list) is outside of the size of your array or list. The way your list works, you have added "pt" in line 68...so your list has one element in it. Once you start in the for loop, you are adding other elements. The first time you go into the loop, you add a point, your list has two elements, upperbound index is 1. But then you increment the i variable, so the next time you go into the loop, line 72 is looking for list_pt(2) when you actually should just be on list_pt(1)...anyways...try it out and see if it does what you need...

Luis

Permalink Reply by Rui de Klerk on June 17, 2009 at 10:51am

So that was it?! Thanks a LOT Luis, it worked just fine ;)

I didn't know the For loop made the increments by itself - back when i programmed with fortran90 we had to do it inside!

No wonder i couldn't figure it out...

Thanks!

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