TheSwamp

Code Red => AutoLISP (Vanilla / Visual) => Topic started by: dubb on February 10, 2017, 12:12:02 PM

Title: Wrong calculation using FIX and 2 points.
Post by: dubb on February 10, 2017, 12:12:02 PM

Using this snippet script to calculate the distance. The result is 1 unit less than what I expected :tickedoff:. The unexpected calculated results only occurs on parallel lines that are angled. Horizontal parallel lines seem to calculate as expected. Screenshot included.

Script used to pick points.

Code: [Select]

(setq pt1 (getpoint "\nSelect first point"))
(setq pt2 (getpoint pt1 "\nSelect second point"))

Script used to calculate the distance.

Code: [Select]

(fix (distance pt1 pt2))

Code: [Select]

Select first point
Select second point_per to
Command:
Command: (fix (distance pt1 pt2))
7

Title: Re: Wrong calculation using FIX and 2 points.
Post by: ronjonp on February 10, 2017, 12:22:42 PM

HERE (https://www.theswamp.org/index.php?topic=52552.msg574643#msg574643) is a thread with a similar problem.

Maybe try: (fix (+ 1e-8 (distance pt1 pt2)))

Title: Re: Wrong calculation using FIX and 2 points.
Post by: dubb on February 10, 2017, 12:37:01 PM

Ahhh! Thanks Ron!  :smitten:
I kinda remember that post. I guess I was using the wrong search query. Though its weird we have to use scientific notation to obtain these results.

Title: Re: Wrong calculation using FIX and 2 points.
Post by: ronjonp on February 10, 2017, 12:38:31 PM

Quote from: dubb on February 10, 2017, 12:37:01 PM

Ahhh! Thanks Ron!  :smitten:
I kinda remember that post. I guess I was using the wrong search query. Though its weird we have to use scientific notation to obtain these results.

Glad to help  :)

Title: Re: Wrong calculation using FIX and 2 points.
Post by: David Bethel on February 11, 2017, 07:40:18 AM

I would suggest using a rounding function in lieu of  ( fix ).  -David

Title: Re: Wrong calculation using FIX and 2 points.
Post by: mailmaverick on February 14, 2017, 04:32:44 AM

Quote from: David Bethel on February 11, 2017, 07:40:18 AM

I would suggest using a rounding function in lieu of  ( fix ).  -David

Something like : http://www.lee-mac.com/round.html (http://www.lee-mac.com/round.html)