help with function rtos

[leonucadomi]

hello masters:

I am using a formula

 

(setq weight ( rtos (/ (atof dato1) 1000) 2 3))
(princ weight)

 

I need it to show three numbers after the decimal point

example : 36.560

 

The problem is that even though I indicated  "3"

in rtos , truncates me to 36.56

I mean it doesn't show me the last zero

 

Someone knows something about it?

 

thanks

 

 

 

 

 

[pkenewell]

@leonucadomi See this routine on Lee Mac's website: http://www.lee-mac.com/consistentrtos.html

[leonucadomi]

excellent , thanks

[Lee Mac]

Essentially, DIMZIN is the reason.

[fuccaro]

This will truncate your string to 3 decimals:

(princ (setq weight (/ (fix (* 1000 (atof dato1)))1000.0)))

 

If you wish to round the result, use something like this:

(rtos (atof dato1) 2 3)

 

[fuccaro]

(setq s "123.456789")
(setq decs 3) ; desired number of decimals
(setq a (substr s 1 (+ 1 decs (vl-string-search "." s))))

If the initial number is already a string, and what you need is also a sting, you can use only string operations, there is no need to convert to number.