Limiting Precision of Decimals,

Hi rebols, Is there any way to avoid scientific notation on decimals? For example, I don't want the E-2 at the end of the following number my program has calculated: 6.59262575231111E-2 I want instead: .06592625 <====<<< I would like less precision also. Louis

Hi Louis, << Is there any way to avoid scientific notation on decimals? For example, I don't want the E-2 at the end of the following number my program has calculated: >> Here's a rounding function that might do what you want. ; Ladislav Mecir, Gregg Irwin (minor adjustment) mod: func [ {Compute a remainder.} value1 [number! money! time!] {The dividend} value2 [number! money! time!] {The divisor} /euclid {Compute a non-negative remainder such that: a = qb + r and r < b} /local r ] [ either euclid [ either negative? r: value1 // value2 [r + abs value2] [r] ;-- Alternate implementation ;value1 // value2 + (value2: abs value2) // value2 ][ value1 // value2 ] ] ;-- Note: to-interval does mod-like rounding. If the interval you ; specify is not evenly divisble into your base, the result ; may not be what you expect. E.g. round/to-interval 133 30 ; will round to 120, not 130, because 120 is an even multiple ; (read interval) of 30. ; Ladislav Mecir, Gregg Irwin round: func [ {Rounds numeric value with refinements for what kind of rounding you want performed, how many decimal places to round to, etc.} value [number! money! time!] {The value to round} /up {Round away from 0} /floor {Round towards the next more negative digit} /ceiling {Round towards the next more positive digit} /truncate {Remaining digits are unchanged. (a.k.a. down)} /places {The number of decimal places to keep} pl [integer!] /to-interval {Round to the nearest multiple of interval} interval [number! money! time!] /local factor ][ ;-- places and to-interval are redundant. E.g.: ; places 2 = to-interval .01 ; to-interval is more flexible so I may dump places. ;-- This sets factor in one line, under 80 chars, but is it clearer? ;factor: either places [10 ** (- pl)][either to-interval [interval][1]] factor: either places [ 10 ** (negate pl) ] [ either to-interval [interval] [1] ] ;-- We may set truncate, floor, or ceiling in this 'if block. if not any [up floor ceiling truncate] [ ;-- Default rounding is even. Should we take the specified ; decimal places into account when rounding? We do at the ; moment. either (abs value // factor) <> (.5 * factor) [ value: (.5 * factor) + value return value - mod/euclid value factor ] [ ;-- If we get here, it means we're rounding off exactly ; .5 (at the final decimal position that is). either even? value [ truncate: true ] [ either negative? value [floor: true][ceiling: true] ] ] ] if up [either negative? value [floor: true][ceiling: true]] if truncate [return value - (value // factor)] if floor [return value - mod/euclid value factor] if ceiling [return value + mod/euclid (negate value) factor] ] --Gregg

Hi Gregg, Thanks! But I haven't been able to figure out how to use it. Would you please give me a sample usage? Louis At 04:58 PM 5/24/2002 -0600, you wrote:

Hi Louis, << Thanks! But I haven't been able to figure out how to use it. Would you please give me a sample usage? >> DOH! I was going to post a simple reply, but it appears you've outsmarted me. :) If there's only a decimal component, and the value is <~.1, REBOL returns it with scientific notation. E.g.

>> round/places/truncate 1.0659262575231111 8

>> round/places/truncate .0659262575231111 8

--- Gregg Irwin <[greggirwin--mindspring--com]> wrote:

> Hi Louis, > << Thanks! But I haven't been able to figure out > bug! :) > Anyone else listening in? Any thoughts?

Hi Gregg, On Saturday, May 25, 2002, 5:37:55 AM, you wrote: (CC to Gregg and Luis to avoid list slowness) GI> Anyone else listening in? Any thoughts? Sorry for using a nonstandard style... You should be easily able to fix it for negative numbers (I didn't need them :) and to use different decimal separators (this is for the italian way). form-decimal: func [ num [number!] cifre [integer!] /local str poscifre ] [ ; ***WARNING*** positive numbers only. num: abs num str: make string! 16 either zero? num [ insert str #"0" if cifre > 0 [ insert/dup insert tail str #"," #"0" cifre ] ] [ if 14 < add cifre log-10 num [ return form num] num: form add multiply power 10 cifre to-decimal num 0,5 clear any [find num "." ""] poscifre: skip tail num negate cifre insert/part str num num: skip num 1 + remainder subtract index? poscifre 2 3 while [(index? poscifre) > (index? num)] [ insert/part insert tail str #"'" num num: skip num 3 ] if empty? str [insert str #"0"] if not tail? poscifre [ insert insert/dup insert tail str #"," #"0" cifre - length? poscifre poscifre ] ] str ]

>> form-decimal 1 2

>> form-decimal 1000 2

>> form-decimal 0.1 2

>> form-decimal 0.01 2

>> form-decimal 0.01 5

>> form-decimal 0.00001 5

>> d: .0659262575231111

>> form-decimal d 5

Hi Louis and Gregg

> Anyone else listening in? Any thoughts?

Thanks Chris, Gabriele, and Romano! Louis, it looks like you have a few options to pursue here. I'll be looking into them as well but let me know if, other than formatting, the ROUND function misbehaves. --Gregg

Gregg, Chris, Gabriele, and Romano, Thanks for all the help. I'm still studying your code. I get back with you ASAP (I still have a lot to learn). Louis