(but my results with this using slice() was about the same with Firefox.
n=1000000; a = new Array(n);
for (var i = a.length;--i >= 0;) {a[i] = i;}
t1=performance.now(); b = a.slice();
t2=performance.now(); c = new Array(n);
for (var i = a.length;--i >= 0;)
{ c[i] = a[i] }
t3=performance.now(); dt1= t2 - t1; dt2= t3 - t2;
a[5] =-5;
msg='slice: ' + dt1 + 'ms copy: ' + dt2 + 'ms a[5]=' + a[5] +
'b[5]=' + b[5] + ' c[5]=' + c[5];
alert(msg)
On Fri, Dec 18, 2015 at 3:00 PM, Robert Hanson <hans...@stolaf.edu> wrote:
> I'm not sure the Java data are significant -- all you are seeing there is
> the overhead for executing JavaScript from Java. The Java itself has
> nothing to do with it, since the loop is in JavaScript.
>
> Note that you need to use .slice() not .slice(0). The latter just pulls
> the first value out.
>
> On Fri, Dec 18, 2015 at 2:43 PM, Rolf Huehne <rhue...@leibniz-fli.de>
> wrote:
>
>> On 12/18/2015 09:05 PM, Robert Hanson wrote:
>> > Oh, yes. .slice() copies all or part of an array.
>> >
>> The independence of 'n' was caused because the elements of the copied
>> array were all undefined. I have changed the test and filled the array
>> with values first:
>>
>> ---- Jmol script --------------------------
>> jsCommand = "n=1000000; a = new Array(n); for (var i = a.length;--i >=
>> 0;) {a[i] = i;} t1=performance.now(); b = a.slice(0);
>> t2=performance.now(); c = new Array(n); for (var i = a.length;--i >= 0;)
>> { c[i] = a[i] } t3=performance.now(); dt1= t2 - t1; dt2= t3 - t2; a[5] =
>> -5; msg='slice: ' + dt1 + 'ms copy: ' + dt2 + 'ms a[5]=' + a[5] + '
>> b[5]=' + b[5] + ' c[5]=' + c[5]; alert(msg)";
>> javascript @jsCommand;
>> ---------------------------------------------
>>
>> Now 'slice' also depends on 'n':
>> Firefox/HTML5: 4ms
>> Firefox/Java: 4ms
>> Chromium/HTML5: 10ms
>> Chromium/Java: 7ms
>>
>> And the new values for 'copy' are:
>> Firefox/HTML5: 500ms
>> Firefox/Java: 4000ms
>> Chromium/HTML5: 700ms
>> Chromium/Java: 130ms
>>
>> Bob and others, do you have any idea why there is such a huge
>> performance difference in running the same Javascript code from
>> JSmol/Java or JSmol/HTML5 and that in a different direction for Firefox
>> and Chrome?
>>
>> Regards,
>> Rolf
>> --
>>
>> Rolf Huehne
>> Postdoc
>>
>> Leibniz Institute on Aging - Fritz Lipmann Institute (FLI)
>> Beutenbergstrasse 11
>> 07745 Jena, Germany
>>
>> Phone: +49 3641 65 6205
>> Fax: +49 3641 65 6210
>> E-Mail: rhue...@leibniz-fli.de
>> Website: http://www.leibniz-fli.de
>>
>> Scientific Director: Prof. Dr. K. Lenhard Rudolph
>> Head of Administration: Dr. Daniele Barthel
>> Chairman of Board of Trustees: Burkhard Zinner
>>
>> VAT No: DE 153 925 464
>> Register of Associations: No. 230296, Amtsgericht Jena
>> Tax Number: 162/141/08228
>>
>>
>>
>> ------------------------------------------------------------------------------
>> _______________________________________________
>> Jmol-users mailing list
>> Jmol-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/jmol-users
>>
>
>
>
> --
> Robert M. Hanson
> Larson-Anderson Professor of Chemistry
> Chair, Department of Chemistry
> St. Olaf College
> Northfield, MN
> http://www.stolaf.edu/people/hansonr
>
>
> If nature does not answer first what we want,
> it is better to take what answer we get.
>
> -- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900
>
>
--
Robert M. Hanson
Larson-Anderson Professor of Chemistry
Chair, Department of Chemistry
St. Olaf College
Northfield, MN
http://www.stolaf.edu/people/hansonr
If nature does not answer first what we want,
it is better to take what answer we get.
-- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900
------------------------------------------------------------------------------
_______________________________________________
Jmol-users mailing list
Jmol-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/jmol-users
