Groups > comp.lang.java.programmer > #25126

Re: Autoboxing and Performance ?

Newsgroups	comp.lang.java.programmer
Date	2013-08-23 11:08 -0700
References	(5 earlier) <b7lk0hFpbj9U1@mid.dfncis.de> <5csRt.197906$jW3.50636@fx23.iad> <kv5p7j$30v$1@dont-email.me> <units-20130822220059@ram.dialup.fu-berlin.de> <kv5v87$1og$1@dont-email.me>
Message-ID	<92908c21-7db9-4ddc-8dc5-ed14d4ab8406@googlegroups.com> (permalink)
Subject	Re: Autoboxing and Performance ?
From	Lew <lewbloch@gmail.com>

Show all headers | View raw

Martin Gregorie wrote:
> Stefan Ram wrote:
>>   Moreover, a lenght (in physics) /does not have/ a unit!
>>
> 
> As a chemistry graduate I disagree quite strongly with that. Its quite 
> impossible to calculate anything without knowing the units the givens 
> were measured in. I seem to recall a certain NASA Mars probe failing 
> because the units used to measure fuel remaining were unstated. As a 
> result somebody calculated burns wrongly by confusing lbs and kg, causing 
> the probe to run out of fuel and miss Mars entirely.

If read carefully, he didn't say the unit shouldn't be known, only that that knowledge 
should be prior to run-time.

A certain Mars probe would have landed if that unit were properly communicated by 
memo. It need not have been encoded in the computer.

You are correct that the problem was that the unit was unstated. That is not at issue. 
What is at issue is where that statement should be made.

>>   For example, there is a certain distance from the sun to the Procyon,
>>   what is the unit of that lenght? As a physical value, it has no unit!
>>   Only when one wants to write it down, one has to choose a certain unit
>>   system and number system, and one can choose every unit system one
>>   likes. This is an artefact of our notation, not a property of the
>>   length.
>>
> 
> If you don't know the units the measurement was made in, its a 
> meaningless number that can't be used to calculate a valid result any 

Again, it is not in dispute that the unit is needed for communication. 

> more than you can add "not very far" to "a huge distance" and get a 
> measurable distance.

And yet again, measurement of a distance does require a unit. It is distance 
itself that does not.

I didn't read any post here that attempts to refute the necessity of units for 
calculation and communication.

I do read two positions, one that the unit should be communicated out of band 
and the other that it should be encoded in the software.

Like all engineering decisions, the choice depends on the need of the system at 
hand. Each has features that render it more optimal for some scenarios and less 
for others.

-- 
Lew

Thread

Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:15 -0500
  Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-20 12:20 +0200
    Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 05:33 -0500
      Re: Autoboxing and Performance ? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2013-08-20 10:43 +0000
        Re: Autoboxing and Performance ? Peter Olcott <OCR4Screen> - 2013-08-20 06:04 -0500
          Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 08:08 -0400
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:15 -0400
      Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:12 -0400
      Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-21 03:52 +0300
        Re: Autoboxing and Performance ? Sebastian <news@seyweiler.dyndns.org> - 2013-08-21 07:27 +0200
          Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 18:43 -0400
            Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 08:08 +0300
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-22 07:56 +0300
            Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 10:51 -0700
              Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 19:36 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 13:01 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-22 21:19 +0000
                Re: Autoboxing and Performance ? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-08-22 14:39 -0700
                Re: Autoboxing and Performance ? markspace <markspace@nospam.nospam> - 2013-08-22 19:50 -0700
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:16 +0000
                Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-24 17:20 +0300
                Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-23 11:08 -0700
                Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-23 22:52 +0200
                Re: Autoboxing and Performance ? Jim Gibson <jimsgibson@gmail.com> - 2013-08-23 16:38 -0700
                Re: Autoboxing and Performance ? "John B. Matthews" <nospam@nospam.invalid> - 2013-08-23 06:17 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-23 17:25 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-25 18:34 -0400
                Re: Autoboxing and Performance ? Jeff Higgins <jeff@invalid.invalid> - 2013-08-28 10:52 -0400
                Re: Autoboxing and Performance ? Martin Gregorie <martin@address-in-sig.invalid> - 2013-08-23 23:37 +0000
        Re: Autoboxing and Performance ? Robert Klemme <shortcutter@googlemail.com> - 2013-08-26 19:33 +0200
          Re: Autoboxing and Performance ? Sven Köhler <remove-sven.koehler@gmail.com> - 2013-08-29 10:09 +0300
            Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-29 14:14 +0200
      Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 21:28 -0300
  Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-20 20:03 +0200
    Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-20 16:23 -0700
      Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:51 +0200
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:39 -0700
          Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 16:51 +0100
        Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:19 -0400
          Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-22 09:49 +0200
    Re: Autoboxing and Performance ? Jan Burse <janburse@fastmail.fm> - 2013-08-21 11:54 +0200
  Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-20 20:06 -0400
    Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-20 21:19 -0400
      Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-21 10:05 +0200
        Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 07:19 -0400
          Re: Autoboxing and Performance ? Joerg Meier <joergmmeier@arcor.de> - 2013-08-22 00:18 +0200
            Re: Autoboxing and Performance ? Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-08-21 19:58 -0400
        Re: Autoboxing and Performance ? Lew <lewbloch@gmail.com> - 2013-08-21 08:36 -0700
      Re: Autoboxing and Performance ? taqmcg@gmail.com - 2013-08-21 09:37 -0700
  Re: Autoboxing and Performance ? Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-08-20 23:28 -0500
  Re: Autoboxing and Performance ? lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-08-21 10:09 +0100
    Re: Autoboxing and Performance ? Arne Vajhøj <arne@vajhoej.dk> - 2013-08-21 19:04 -0400
      Re: Autoboxing and Performance ? Arivald <NOSPAMarivald@interia.pl> - 2013-08-22 07:39 +0200
  Re: Autoboxing and Performance ? Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-08-29 01:42 -0300

csiph-web