Is there a script that will round off a number to a certain number of
decimal places? -Allen Thompson
decimal places? -Allen Thompson
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Re: rounding off numbers
In article <LxGCb.99$sW5.5 0@newsread2.new s.atl.earthlink .net>, Allen
Thompson <genericjoe@min dspring.com> wrote:
[color=blue]
> Is there a script that will round off a number to a certain number of
> decimal places? -Allen Thompson
>
>[/color]
1. Let x = the number of decimal places you want.
2. Multiply the number by 10 raised to x.
3. Use Math.round() on the answer.
4. Divide by the number obtained in 2.
--
Dennis M. Marks
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
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Re: rounding off numbers
Dennis M. Marks wrote:[color=blue]
> In article <LxGCb.99$sW5.5 0@newsread2.new s.atl.earthlink .net>, Allen
> Thompson <genericjoe@min dspring.com> wrote:
>
>[color=green]
>>Is there a script that will round off a number to a certain number of
>>decimal places? -Allen Thompson
>>
>>[/color]
>
>
> 1. Let x = the number of decimal places you want.
> 2. Multiply the number by 10 raised to x.
> 3. Use Math.round() on the answer.
> 4. Divide by the number obtained in 2.
>[/color]
or use the toFixed() method of the Number object:
Comment
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Re: rounding off numbers
In article <brfn22$oqs$1@s parta.btinterne t.com>, bagbourne <noway@noway.co m>
writes:
[color=blue]
>Dennis M. Marks wrote:[/color]
<--snip-->
[color=blue]
>
>or use the toFixed() method of the Number object:[/color]
alert((0.007).t oFixed(2)
//gives 0.00
Which is dropping it to two decimal places, *not* rounding it.
--
Randy
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Re: rounding off numbers
bagbourne a ecrit :
[color=blue]
> or use the toFixed() method of the Number object:
>
> http://devedge.netscape.com/library/...r.html#1193137[/color]
very interesting
they send me to a page to tell me to download NN7
beuark ! :-(((
--
*************** *************** *************** *************** **
Stéphane MORIAUX : mailto:stephane OTER-MOImoriaux@wana doo.fr
Aide aux Pages Perso (images & couleurs, formulaire, CHP, JS)
*************** *************** *************** *************** **
Comment
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Re: rounding off numbers
In article <20031213155410 .11891.00002906 @mb-m11.aol.com>,
HikksNotAtHome <hikksnotathome @aol.com> wrote:
[color=blue]
> In article <brfn22$oqs$1@s parta.btinterne t.com>, bagbourne <noway@noway.co m>
> writes:
>[color=green]
> >Dennis M. Marks wrote:[/color]
>
> <--snip-->
>[color=green]
> >
> >or use the toFixed() method of the Number object:[/color]
>
> alert((0.007).t oFixed(2)
> //gives 0.00
>
> Which is dropping it to two decimal places, *not* rounding it.[/color]
What kind of misquoting are you doing? My response was about
Math.round() NOT TOFIXED. MY RESPONSE WAS AS FOLLOWS:
1. Let x = the number of decimal places you want.
2. Multiply the number by 10 raised to x.
3. Use Math.round() on the answer.
4. Divide by the number obtained in 2.
--
Dennis M. Marks
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
Comment
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Re: rounding off numbers
"Dennis M. Marks" a ecrit :
[color=blue]
> My response was about
> Math.round() NOT TOFIXED. MY RESPONSE WAS AS FOLLOWS:
> 1. Let x = the number of decimal places you want.
> 2. Multiply the number by 10 raised to x.
> 3. Use Math.round() on the answer.
> 4. Divide by the number obtained in 2.[/color]
and ???
x = Math.round(2*10 00)/1000;
gives
x = 2
where are the missing .000 to obtain 2.000
--
*************** *************** *************** *************** **
Stéphane MORIAUX : mailto:stephane OTER-MOImoriaux@wana doo.fr
Aide aux Pages Perso (images & couleurs, formulaire, CHP, JS)
*************** *************** *************** *************** **
Comment
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Re: rounding off numbers
"Dennis M. Marks" <denmarks@dcsi. net> wrote in message
news:1312200315 06178104%denmar ks@dcsi.net...[color=blue]
>In article <20031213155410 .11891.00002906 @mb-m11.aol.com>,
>HikksNotAtHo me <hikksnotathome @aol.com> wrote:
>[color=green]
>>In article <brfn22$oqs$1@s parta.btinterne t.com>,
>>bagbourne <noway@noway.co m> writes:
>>[color=darkred]
>>>Dennis M. Marks wrote:[/color]
>>
>><--snip-->[color=darkred]
>>>
>>>or use the toFixed() method of the Number object:[/color]
>>
>>alert((0.007) .toFixed(2)
>>//gives 0.00
>>
>>Which is dropping it to two decimal places, *not*
>>rounding it.[/color]
>
>What kind of misquoting are you doing? ...[/color]
<snip>
There is no misquoting, Randy is responding to bagbourne's reply to your
post and has quoted the parts of that post that he is responding to
verbatim.
Richard.
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Re: rounding off numbers
In article <3FDBA9A9.E426D 870@wanadoo.fr> , <"@SM"> wrote:
[color=blue]
> "Dennis M. Marks" a ecrit :
>[color=green]
> > My response was about
> > Math.round() NOT TOFIXED. MY RESPONSE WAS AS FOLLOWS:
> > 1. Let x = the number of decimal places you want.
> > 2. Multiply the number by 10 raised to x.
> > 3. Use Math.round() on the answer.
> > 4. Divide by the number obtained in 2.[/color]
>
> and ???
>
> x = Math.round(2*10 00)/1000;
> gives
> x = 2
> where are the missing .000 to obtain 2.000
>[/color]
<snip>
The original question was:
Is there a script that will round off a number to a certain number of
decimal places? -Allen Thompson
It did not state "display" a certain number of decimal places. My
answer is mathematically correct. To show trailing zeros after the
decimal point text zeros would have to be affixed to the end. It's too
bad that javascript doesn't have output formatting like some other
languages.
--
Dennis M. Marks
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Comment
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Re: rounding off numbers
JRS: In article <13122003082539 8921%denmarks@d csi.net>, seen in
news:comp.lang. javascript, Dennis M. Marks <denmarks@dcsi. net> posted at
Sat, 13 Dec 2003 08:25:39 :-[color=blue]
>In article <LxGCb.99$sW5.5 0@newsread2.new s.atl.earthlink .net>, Allen
>Thompson <genericjoe@min dspring.com> wrote:
>[color=green]
>> Is there a script that will round off a number to a certain number of
>> decimal places?[/color][/color]
That is not, as written, a meaningful question. All javascript numbers
are 64-bit IEEE Doubles, floating-point binary. Only strings can have
decimal places. Presumably you want to start with a variable (or
expression) of type Number, and generate a String representing that
number in decimal with two digits after the decimal point, probably for
display.
You should have read the FAQ before posting; all of it, but item 4.6
refers.
[color=blue]
>1. Let x = the number of decimal places you want.
>2. Multiply the number by 10 raised to x.
>3. Use Math.round() on the answer.
>4. Divide by the number obtained in 2.[/color]
That is the answer to a different question than the one almost certainly
intended.
You too should have read the FAQ before posting. That gives the nearest
(give or take) Number which is a multiple of 10^-x. When displayed,
that result will be shown with no more than x digits after the point;
but there may be fewer. One might get # or #.# or #.## if x=2.
The version in the FAQ has
if (S.search && S.search(/\D/)!=-1) { return ''+X }
If S.search does not exist, but S.search(/\D/) would have succeeded, the
return does not occur. But the following code was written on the
assumption that the search had, or would have, failed.
I now use
if (/\D/.test(S)) { return ''+X }
on the basis that it should work in Javascript 1.2 and higher, which is
adequate.
Otherwise, is there a brief method of testing for a non-digit that works
in earlier javascript? Better than
for (x=0;x<S.length ;x++) if ((t=S.charAt(x) )<'0'||t>'9') return ''+X
?
--
© John Stockton, Surrey, UK. ?@merlyn.demon. co.uk Turnpike v4.00 IE 4 ©
<URL:http://jibbering.com/faq/> Jim Ley's FAQ for news:comp.lang. javascript
<URL:http://www.merlyn.demo n.co.uk/js-index.htm> Jsc maths, dates, sources.
<URL:http://www.merlyn.demo n.co.uk/> TP/BP/Delphi/Jsc/&c, FAQ topics, links.
Comment
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Re: rounding off numbers
@SM wrote on 14 Dec 2003 at Sun, 14 Dec 2003 00:07:11 GMT:
[color=blue]
> x = Math.round(2*10 00)/1000;
> gives
> x = 2
> where are the missing .000 to obtain 2.000[/color]
To be fair, the OP mentioned nothing about trailing zeros, just
performing rounding. They are not the same thing. The rounding may
just be part of a calculation.
If the question was: "How do I display a floating-point value to a
certain number of decimal places?", then you could argue about the
missing zeros.
Mike
--
Michael Winter
M.Winter@blueyo nder.co.invalid (replace ".invalid" with ".uk")
Comment
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Re: rounding off numbers
Dennis M. Marks hu kiteb:
[color=blue][color=green]
>> Which is dropping it to two decimal places, *not* rounding it.[/color]
>
>
> What kind of misquoting are you doing? My response was about
> Math.round() NOT TOFIXED. MY RESPONSE WAS AS FOLLOWS:[/color]
Hey Dennis, you need to lay off the coffee for a while. There wasn't any
misquoting, he was simply talking at a slight tangent.
--
--
Fabian
Visit my website often and for long periods!
Comment
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Re: rounding off numbers
Here is an actual code example of the formula defined by Dennis Marks.
function number_ClipToTh eHundredth(valu e) {
return Math.round(pars eFloat(value) * 100)/100;
}
Change the 100 to any decimal place you want, 10, 100, 1000 (10^x).
Mike
"Allen Thompson" <genericjoe@min dspring.com> wrote in message
news:LxGCb.99$s W5.50@newsread2 .news.atl.earth link.net...[color=blue]
> Is there a script that will round off a number to a certain number of
> decimal places? -Allen Thompson
>
>[/color]
Comment
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Re: rounding off numbers
Mike hu kiteb:
[color=blue]
> Here is an actual code example of the formula defined by Dennis Marks.
>
> function number_ClipToTh eHundredth(valu e) {
> return Math.round(pars eFloat(value) * 100)/100;
> }
>
> Change the 100 to any decimal place you want, 10, 100, 1000 (10^x).[/color]
To avoid floating errors, it is wise to leave the final divisor off
until you are ready to display the number. Wherver possible, it is best
to use whole numbers in javascript.
--
--
Fabian
Visit my website often and for long periods!
Comment
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Re: rounding off numbers
"Fabian" <lajzar@hotmail .com> wrote in news:brgqee$33v jm$2@ID-
174912.news.uni-berlin.de:
[color=blue]
> To avoid floating errors, it is wise to leave the final divisor off
> until you are ready to display the number. Wherver possible, it is best
> to use whole numbers in javascript.[/color]
Or any language in which arithmetic is done in floating point. For
example, when doing financial calculations, the rule is always to convert
all the numbers you use into the smallest units you do business with (for
ordinary commerce, that would be cents or your country's equivalent) and
only convert to larger units (e.g. dollars) at the very end.
There's an entire branch of mathematics (numerical analysis) devoted to the
study of the consequences of dealing with concrete representations of
numbers rather than ideal abstract numbers. When you study numerical
analysis you learn, for example, that if you try to subtract one large
floating-point number from another larger floating-point number that's
nearly equal to it, you cand lose nearly all of your significant digits
(which means, among other things, that the textbook formula for single-pass
computation of the standard deviation of a set of data often fails when
implemented on a computer). And that if you try to compare two floating-
point numbers for exact equality, you often get surprising results. Try:
for (i=0;i<=10;i+=0 .1) {document.write (i+"<br>");}
and you'll find that the last value displayed isn't exactly ten. Floating-
point numbers are *approximations * to real numbers. Floating-point
addition, for example, isn't strictly associative even though real-number
addition is.
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