Saving real number to string while saving the precision?

(setq VALUE 5.0)
would equal
(rtos VALUE 2 1)

(setq VALUE 5.00)
would equal
(rtos VALUE 2 2)

(setq VALUE 5.00568)
would equal
(setq VALUE (rtos VALUE 2 5))

Thoughts?

 

Actual decimal values ( .00568 ) precision could be extracted. The .00
values will be next to impossible. -David

 

Once upon a time I had this issue, and I wrote a routine using (rtos) and
set the precision to 8 places, more than we ever needed in what we were
doing. Then, I wrote a simple function to strip off the trailing zeros.

 

That might just work 'good enough'. How about something like this? Extra
trailing Zero's I don't really care about. I just want to make sure that if
I decide to store a number with this that I'm able to get it back.

==============================================
(defun C:REALTOSTRING (/ REALNUMBER REALSTR CNT)
(setq REALNUMBER (getreal "\nEnter a number: "))
(setq REALSTR (rtos REALNUMBER 2 10))
(setq CNT (strlen REALSTR))
(while
(or
(= "." (substr REALSTR CNT 1))
(= "0" (substr REALSTR CNT 1))
)
(setq CNT (- CNT 1))
)
(setq REALSTR (substr REALSTR 1 CNT))
(prompt (strcat "\nYou specified number: " REALSTR))
(princ)
)

 

Looks fine to me! I tried it and it works...

 

???

REALTOSTRING
Enter a number: 1000
You specified number: 1

REALTOSTRING
Enter a number: 10.0
You specified number: 1

REALTOSTRING
Enter a number: 10.00
You specified number: 1

--

 

Lets try this...

(defun C:REALTOSTRING (/ REALNUMBER REALSTR CNT)
(setq REALNUMBER (getreal "\nEnter a number: "))
(setq REALSTR (rtos REALNUMBER 2 10))
(setq CNT (strlen REALSTR))
(while (= "0" (substr REALSTR CNT 1))
(setq CNT (- CNT 1))
)
(if (= "." (substr REALSTR CNT 1))
(setq CNT (- CNT 1))
)
(setq REALSTR (substr REALSTR 1 CNT))
(prompt (strcat "\nYou specified number: " REALSTR))
(princ)
)

 

REALTOSTRING
Enter a number: 1000
You specified number: 1

REALTOSTRING
Enter a number: 10.0
You specified number: 1

REALTOSTRING
Enter a number: 10.00
You specified number: 1

--
________________________________________________

Marc'Antonio Alessi (TV) Italy
(strcat "NOT a " (substr (ver) 8 4) " guru.")

O.S. = XP Pro 2002 Ita - Sp.1
AutoCAD = 2004 Ita - Sp.1a
________________________________________________

 

Sage:

It can be handled for you by the DIMZIN variable...
Command: (setvar "dimzin" 8)
8

Command: (rtos 12.05 2 10)
"12.05"

Command: (rtos 0.05 2 10)
"0.05"

Command: (rtos pi 2 10)
"3.1415926536"