F(x,y) need some help with expression plz!!!

can i insert something like 10 < height < maxheight into the F input as my expression to solve?

i tried it-cause i need some sort of interval. would be better if my lower limit (the 10) could also be controlled by a numeric slider- but somehow thats not working.
- i need this to select plines according to their length. for example: i got 100 plines with lengths between 10 and 70. and i want to select those with lengths from 20 to 40 and from 40 to 60.

hope someone can help me! if needed ill attach some file to explain.
added a pic of my definition- i can select both, the smallest and the biggest curves but if i want to select those inbetween in doesnt work.- i guess its easy and im using the wrong method-

btw: anyone knows: when i sweep along a railcurve my surface gets extremly twisted- when i remove some controlpoints of the railcurve- the twists disappear.-dont know why- i guess, again some basic knowledge is missing.

thx michael

Attachments:

selectcurvesbysize.bmp, 2.5 MB

Replies to This Discussion

Permalink Reply by michael b on May 4, 2010 at 5:10am

when i insert x={y,z} and y and z are my numeric boundaries it aint working. {y,z} would be my interval right? so if x would be equal to any of those numbers in this interval the curve should be selected :(
hmm i dont get it, sorry

Permalink Reply by Simon Kallioinen on May 4, 2010 at 6:01am

I'm not sure I understand your question. But you should probably use the < or > module if you want to select curve based on a comparison. See the image... Is that what you're after?

Permalink Reply by Danny Boyes on May 4, 2010 at 5:51am

This can be done with ordinary GH components:

Permalink Reply by michael b on May 4, 2010 at 6:27am

thx danny- i guess i was just playin round with the wrong tools- hmm no brep, no expressions needed :)

Permalink Reply by Vicente Soler on May 4, 2010 at 1:16pm

You can use the expression component to clean up the canvas.
10 < height < maxheight would be:
(10 < height) and (height < maxheight)
Rename the inputs of the component to match the variable names.

Permalink Reply by michael b on May 4, 2010 at 12:04pm

thx simon. it worked out great. i got now three different selections of my profiles.- and have another problem with lofting...zzzz i never run out of problems :D

anyone knows how to select all profiles- get the x values of them in a list- in order to loft them.
my loft looks weird and i guess the problem is that i have to reorganize them-

-im not sure if im right- but i would say ill put a point on every curve- like sayin the midpoint- than decompose the point into x,y,z components.- but then i get some problems- i dont really know how to handle lists and stuff.

would be nice if u could help me, again ;)

Permalink Reply by paloma on December 16, 2010 at 8:28am

Hope is not too late:

To manage the lists you should sort list or ad a flatten component

but the loft is giving you problems because of the direction of the curves, if one of the curves has a different direction it will not loft, to solve this you should add a flip component.

Best

Permalink Reply by michael b on May 5, 2010 at 3:02am

thx vicente! so all i did wrong, i forgot the brackets!
thx again!!

Permalink Reply by paloma on December 16, 2010 at 8:25am

Hi Michael, I´m new in this too, so please would you send a pic of your definition?

Thanks in advance

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