Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Alexander Burger
Hi Jimmie, > What I didn't see in any of the examples is this > > : (format (*/ 9.9 9.789 9.56789 `(* 1.0 1.0)) *Scl) >-> "927.234744579000" Good idea! I added this example to the reference of '*/' ♪♫ Alex -- UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe

Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Jimmie Houchin
Hello, I am trying to understand something about PicoLisp and Fixpoint numbers. I am writing an app and would consider PicoLisp should I get my head around Lisp. But I do not understand how to use numbers. I use a lot of floating point numbers and lots of calculations. From simple

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Aatos Heikkinen
I´ve found ´format´ and ´round´ functions quite helpful, see https://the-m6.net/blog/fixed-point-arithmetic-in-picolisp.html On 12 Jul 2017 18:52, "Jimmie Houchin" wrote: > Hello, > > I am trying to understand something about PicoLisp and Fixpoint numbers. > > I am writing

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Jimmie Houchin
Hello, Thanks for all the help. It is a little more complicated than in languages with support for floating point, but it appears manageable. I think I am slowly wrapping my mind around it. What I didn't see in any of the examples is this : (format (*/ 9.9 9.789 9.56789 `(* 1.0 1.0)) *Scl)

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Alexander Burger
Hi Jimmie, the key is to use the '*/' function for both multiplication and division. '*' is not very useful here. > : (format (* 9.9 9.789 9.56789) 20) > -> "927234744579000." Instead, try : (scl 20) -> 20 : (format (*/ 9.9 9.789

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Jimmie Houchin
Yes, I understand. But not without complicating the calculation to keep track of the number of times I have done multiplication in the current result. Formating with current scale does not work. : (format (* 9.9 9.789 9.56789) 20) ->

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Alexander Burger
On Wed, Jul 12, 2017 at 08:05:42PM +0200, Aatos Heikkinen wrote: > I´ve found ´format´ and ´round´ functions quite helpful, see > https://the-m6.net/blog/fixed-point-arithmetic-in-picolisp.html Yes, this article describes it very well. Especially, it explains Jimmie's issues with multiplication

Re: Floating Point numbers vs Fixpoint numbers

2017-07-12 Thread Christophe Gragnic
On Wed, Jul 12, 2017 at 8:36 PM, Jimmie Houchin wrote: > > I didn't know if PicoLisp provided a solution without complicating every > function which uses multiplication and division. Yes, the */ function: http://software-lab.de/doc/ref_.html#*/ I think you just have to