CAD Forum discussion (EN) : limitations to a real https://www.cadforum.cz/forum_en/ Tue, 21 Apr 2026 01:24:10 +0000 Tue, 14 Dec 2010 08:28:07 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://www.cadforum.cz/forum_en/RSS_post_feed.asp?TID=4905 <![CDATA[CAD Forum discussion (EN)]]> https://www.cadforum.cz/forum_en/forum_images/web_wiz_forums.png https://www.cadforum.cz/forum_en/ <![CDATA[limitations to a real : CarlB, thanks for your answer. I...]]> https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12261&title=limitations-to-a-real#12261 Author: XPeter61
Subject: 4905
Posted: 14.Dec.2010 at 08:28

CarlB,
 
thanks for your answer.
I think this is exactly the information I was looking for.
 
Peter
 
]]> Tue, 14 Dec 2010 08:28:07 +0000 https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12261&title=limitations-to-a-real#12261 <![CDATA[limitations to a real : Nice!! Thanks Carl. I guess I...]]> https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12243&title=limitations-to-a-real#12243 Author: HAWDesigner
Subject: 4905
Posted: 13.Dec.2010 at 23:27

Nice!! Thanks Carl. I guess I learned my 'something new' today.

I have a limited knowledge of LISP, but I do have a background in computer programming and love getting tidbits of info like this.
]]> Mon, 13 Dec 2010 23:27:43 +0000 https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12243&title=limitations-to-a-real#12243 <![CDATA[limitations to a real : Lisp is limited by the same precision...]]> https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12241&title=limitations-to-a-real#12241 Author: CarlB
Subject: 4905
Posted: 13.Dec.2010 at 23:15

Lisp is limited by the same precision as is AutoCAD. It can store 16 digits in a number. To properly display numbers as internally calculated, use the "rtos" function.
 
For your example, you'll see the accurate decimals by setting precision to 1 or higher:
(rtos (+ 100000.0 3.2) 2 1)
 
where the "2" specifies decimal output, "1" is the precision, which can be 0 to 16.
 
With large numbers, the number of decimal places may be less that the precision; such as:
Command: (rtos 1234567890.0987654321 2 16)
"1234567890.098765"
 
]]> Mon, 13 Dec 2010 23:15:52 +0000 https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12241&title=limitations-to-a-real#12241 <![CDATA[limitations to a real : All I can say is the system isn&#039;t...]]> https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12238&title=limitations-to-a-real#12238 Author: HAWDesigner
Subject: 4905
Posted: 13.Dec.2010 at 22:45

All I can say is the system isn't perfect. LISP is a very old language and relied upon many many different factors that probably aren't in place with any of today's technology.

Good Luck!!
]]> Mon, 13 Dec 2010 22:45:50 +0000 https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12238&title=limitations-to-a-real#12238 <![CDATA[limitations to a real : Peter Poeliejoe 04-12-1017:21 When...]]> https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12093&title=limitations-to-a-real#12093 Author: XPeter61
Subject: 4905
Posted: 04.Dec.2010 at 17:43


 Peter Poeliejoe 04-12-10  17:21
When I type this (AutoLISP):

(+ 10000.8 2.4), the result is 10003.2, as expected.

However, when typed: (+ 100000.8 2.4), the result is
100003.0.Is 100000 a magical border voor a real in AutoLISP? Any settings involved here?

Thanks in advance for any brain activity...
Peter
]]> Sat, 04 Dec 2010 17:43:28 +0000 https://www.cadforum.cz/forum_en/forum_posts.asp?TID=4905&PID=12093&title=limitations-to-a-real#12093