Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.physics > #586386 > unrolled thread

Re: Where did the 3 geometric dimensions come from?

Back to article view | Back to sci.physics

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: Where did the 3 geometric dimensions come from? Michael J. Strickland <michael06582@comcast.net> - 2016-06-24 10:38 -0400
    Re: Where did the 3 geometric dimensions come from? Sergio <invalid@invalid.com> - 2016-06-24 10:02 -0500
      Re: Re: Where did the 3 geometric dimensions come from? Michael J. Strickland <michael06582@comcast.net> - 2016-06-25 01:29 -0400
        Re: Where did the 3 geometric dimensions come from? Sergio <invalid@invalid.com> - 2016-06-25 15:01 -0500
      Re: Where did the 3 geometric dimensions come from? "Y.Porat" <y.y.porat@gmail.com> - 2016-06-26 01:04 -0700
    Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-24 16:15 +0000
      Re: Where did the 3 geometric dimensions come from? benj <benj@nobody.net> - 2016-06-24 17:24 -0400
        Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-24 22:03 +0000
          Re: Where did the 3 geometric dimensions come from? benj <benj@nobody.net> - 2016-06-24 18:25 -0400
            Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-24 22:44 +0000
      Re: Re: Where did the 3 geometric dimensions come from? Michael J. Strickland <michael06582@comcast.net> - 2016-06-25 01:33 -0400
        Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-25 15:44 +0000
          Re: Re: Where did the 3 geometric dimensions come from? Michael J. Strickland <michael06582@comcast.net> - 2016-06-26 15:34 -0400
            Re: Where did the 3 geometric dimensions come from? Sergio <invalid@invalid.com> - 2016-06-27 09:06 -0500
    Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-25 16:45 -0500
      Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-25 22:44 +0000
        Re: Where did the 3 geometric dimensions come from? noTthaTguY <abu.kuanysh05@gmail.com> - 2016-06-25 16:10 -0700
        Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-25 18:25 -0500
          Re: Where did the 3 geometric dimensions come from? Sergio <invalid@invalid.com> - 2016-06-25 21:08 -0500
            Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-25 21:58 -0500
            TripolarS from ... wTf are you from, any way noTthaTguY <abu.kuanysh05@gmail.com> - 2016-06-26 16:53 -0700
              Re: TripolarS from ... wTf are you from, any way noTthaTguY <abu.kuanysh05@gmail.com> - 2016-06-26 21:10 -0700
          Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-26 02:04 +0000
            Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-25 22:28 -0500
              Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-26 04:49 +0000
                Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-26 11:23 -0500
                  Re: Where did the 3 geometric dimensions come from? jimp@specsol.spam.sux.com - 2016-06-26 17:33 +0000
                    Re: Where did the 3 geometric dimensions come from? ClutterFreak <ClutterFreak@FakeAddress.com> - 2016-06-26 13:13 -0500

Page 2 of 2 — ← Prev page 1 [2]

#586838 — TripolarS from ... wTf are you from, any way

easily transformed by x - Rcos(alpha) etc. (or
alpha = arcos(x/R) etc., but
I like to use Diadians

> you can address the same "cubic spaces" by braking it up into multi 
> dimensional arrays.  It does not have to correspond to x,y,z, but that 
> is readily convenient.
> 
> It is just addressing a finite set.  If you had infinite items or a lot 
> of them, then spherical, cylendrical or x,y,z make more sense.

[toc] | [prev] | [next] | [standalone]

#586870 — Re: TripolarS from ... wTf are you from, any way

radius times the cosine of one of the three angles,
gives one of the three cartesians

> easily transformed by x :=: Rcos(alpha) etc. (or
> alpha = arcos(x/R) etc., but
> I like to use Diadians

that was the question:
if cartesians are nonpolar .. unipolar .. bipolar;
what is tripolar (or "nonlinear coordination

> > of them, then spherical, cylendrical or x,y,z make more sense.

[toc] | [prev] | [next] | [standalone]

#586729

ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
> On Sat, 25 Jun 2016 22:44:24 -0000,
> jimp@specsol.spam.sux.com wrote:
> 
>> ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
>>> On Fri, 24 Jun 2016 10:38:52 -0400, Michael J.
>>> Strickland wrote:
>>> 
>>>> We could easily number all locations in a cubical area with one
>>>> coordinate starting at top left, near and progressing to bottom, right
>>>> , far
>>> 
>>> I'm not sure but I think computers store 3-D
>>> information in that manner, using only one number to
>>> find various parts of it. 
>> 
>> Ummm, no, computers store 3D information in whatever manner the programmer
>> used, which could be anything. Generally it is in whatever is the easiest
>> convention for the task at hand.
>> 
>> The only computers I have ever heard of that knew anything about coordinates
>> were purpose built analog computers that used spherical coordinates. 
>> 
>> The task of locating a freeway off ramp is very different than the task
>> of defining an object for a 3D printer.
>> 
>> 
> 
> Again I'm not sure (this is very old stuff I'm trying
> to remember) but when you have, say, an array variable
> like A(i,j,k) with i going from 1 to 10, j from 1 to
> 100, and k from 1 to 5 computer allocates memory
> locations for it that form a continuous chain of 5000
> location (each for a different value of that
> variable). And when you want to retrieve what's stored
> at A(3,70,4) computer does 3 + 70*10 + 4*100 = 1103
> and goes to 1103rd position along that chain to get
> the value. It is similar to how Strickland wants to
> access a cubic volume using only one number. 
> 
> But I'm not sure :) 
> 
> Of course you could force the computer store your data
> in any strange way you want, but if you leave it to
> computer to do it that's I believe it does it.

How an array is stored is up to the compiler.

http://stackoverflow.com/questions/2565039/how-are-multi-dimensional-arrays-formatted-in-memory

https://en.wikipedia.org/wiki/Row-major_order


-- 
Jim Pennino

[toc] | [prev] | [next] | [standalone]

#586735

On Sun, 26 Jun 2016 02:04:15 -0000,
jimp@specsol.spam.sux.com wrote:

> ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
>> On Sat, 25 Jun 2016 22:44:24 -0000,
>> jimp@specsol.spam.sux.com wrote:
>> 
>>> ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
>>>> On Fri, 24 Jun 2016 10:38:52 -0400, Michael J.
>>>> Strickland wrote:
>>>> 
>>>>> We could easily number all locations in a cubical area with one
>>>>> coordinate starting at top left, near and progressing to bottom, right
>>>>> , far
>>>> 
>>>> I'm not sure but I think computers store 3-D
>>>> information in that manner, using only one number to
>>>> find various parts of it. 
>>> 
>>> Ummm, no, computers store 3D information in whatever manner the programmer
>>> used, which could be anything. Generally it is in whatever is the easiest
>>> convention for the task at hand.
>>> 
>>> The only computers I have ever heard of that knew anything about coordinates
>>> were purpose built analog computers that used spherical coordinates. 
>>> 
>>> The task of locating a freeway off ramp is very different than the task
>>> of defining an object for a 3D printer.
>>> 
>>> 
>> 
>> Again I'm not sure (this is very old stuff I'm trying
>> to remember) but when you have, say, an array variable
>> like A(i,j,k) with i going from 1 to 10, j from 1 to
>> 100, and k from 1 to 5 computer allocates memory
>> locations for it that form a continuous chain of 5000
>> location (each for a different value of that
>> variable). And when you want to retrieve what's stored
>> at A(3,70,4) computer does 3 + 70*10 + 4*100 = 1103
>> and goes to 1103rd position along that chain to get
>> the value. It is similar to how Strickland wants to
>> access a cubic volume using only one number. 
>> 
>> But I'm not sure :) 
>> 
>> Of course you could force the computer store your data
>> in any strange way you want, but if you leave it to
>> computer to do it that's I believe it does it.
> 
> How an array is stored is up to the compiler.
> 
> http://stackoverflow.com/questions/2565039/how-are-multi-dimensional-arrays-formatted-in-memory
> 
> https://en.wikipedia.org/wiki/Row-major_order
> 
> 

Sure but in both cases what I suspected takes place,
that is a multidimensional array of data gets stored
in a linear form. The second link indicates that the
order by which this linear arrangement is made can be
different (contiguous by row or contiguous by column). 

At first link it shows data from a two dimensional
array are stored in a linear way, but mentions a
complication that may occur trying to access the data
in a function's argument using a common practice
(using a pointer to that data location). 

These are just nitty gritty of the programming
languages and compilers. But data itself is always
stored linearly as it wouldn't make sense to be
otherwise because computer wouldn't understand two or
three dimensionality. 

Thanks god Java programming doesn't deal with memory
allocation :) The links you provided reminded me of C
which I left forever with the advent of Java. No
pointers, no memory allocation / deallocations. Not a
worry in the world compared to C. In Java such tricky
nuisances are all taken care of automatically. 
--
     "zan rAzi mard rAzi gure pedare ghAzi."

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[toc] | [prev] | [next] | [standalone]

#586742

ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
> On Sun, 26 Jun 2016 02:04:15 -0000,
> jimp@specsol.spam.sux.com wrote:

<snip>

>> How an array is stored is up to the compiler.
>> 
>> http://stackoverflow.com/questions/2565039/how-are-multi-dimensional-arrays-formatted-in-memory
>> 
>> https://en.wikipedia.org/wiki/Row-major_order
>> 
>> 
> 
> Sure but in both cases what I suspected takes place,
> that is a multidimensional array of data gets stored
> in a linear form. The second link indicates that the
> order by which this linear arrangement is made can be
> different (contiguous by row or contiguous by column). 
> 
> At first link it shows data from a two dimensional
> array are stored in a linear way, but mentions a
> complication that may occur trying to access the data
> in a function's argument using a common practice
> (using a pointer to that data location). 
> 
> These are just nitty gritty of the programming
> languages and compilers. But data itself is always
> stored linearly as it wouldn't make sense to be
> otherwise because computer wouldn't understand two or
> three dimensionality. 

Computers don't understand anything.

It is the compiler that determines how data will be stored and recovered.

> Thanks god Java programming doesn't deal with memory
> allocation :) The links you provided reminded me of C
> which I left forever with the advent of Java. No
> pointers, no memory allocation / deallocations. Not a
> worry in the world compared to C. In Java such tricky
> nuisances are all taken care of automatically. 

If you think Java "doesn't deal with memory allocation", lord help
anyone that runs a program you write.


-- 
Jim Pennino

[toc] | [prev] | [next] | [standalone]

#586769

On Sun, 26 Jun 2016 04:49:18 -0000,
jimp@specsol.spam.sux.com wrote:

>> Thanks god Java programming doesn't deal with memory
>> allocation :) The links you provided reminded me of C
>> which I left forever with the advent of Java. No
>> pointers, no memory allocation / deallocations. Not a
>> worry in the world compared to C. In Java such tricky
>> nuisances are all taken care of automatically. 
> 
> If you think Java "doesn't deal with memory allocation", lord help
> anyone that runs a program you write.

I said Java programming, not Java. You, the
programmer, do not have to deal with memory
allocation/deallocation at all. Java takes care of it
by itself, and during the program run every now and
then checks and deallocates storage places that are
not being used anymore. It is all done automatically. 

My programs are recreational, being used by myself
alone. I don't know how others felt and why they chose
Java, but in my case the number one reason I went from
C to Java was the absence of this same nuisance of
memory allocation/deallocation and extensive use of
pointer arithmetic. In C you had to control all that
right inside the program you wrote. 

Also in those days (around 1990) deep enough
information about how C handles complicated memory
arrangements was not readily available. Serious
programming was being done still in fortran. Sources
in bookstores and libraries didn't have all the
information needed for complicated cases. By mid 90s
all that could be thrown away using Java.

Java has other conveniences too. But all such
conveniences compared to C are at the expense of a
little loss of speed and loss of a lot of power.
That's why viruses are written in C, not Java. Java is
for "civil" use :) It's deliberately designed to curb
that power. 
--
   "If you always optimize, you'll never be 
    happy." 
                       - Donald Knuth


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[toc] | [prev] | [next] | [standalone]

#586774

ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
> On Sun, 26 Jun 2016 04:49:18 -0000,
> jimp@specsol.spam.sux.com wrote:
> 
>>> Thanks god Java programming doesn't deal with memory
>>> allocation :) The links you provided reminded me of C
>>> which I left forever with the advent of Java. No
>>> pointers, no memory allocation / deallocations. Not a
>>> worry in the world compared to C. In Java such tricky
>>> nuisances are all taken care of automatically. 
>> 
>> If you think Java "doesn't deal with memory allocation", lord help
>> anyone that runs a program you write.
> 
> I said Java programming, not Java. You, the
> programmer, do not have to deal with memory
> allocation/deallocation at all. Java takes care of it
> by itself, and during the program run every now and
> then checks and deallocates storage places that are
> not being used anymore. It is all done automatically. 

Yeah, sure.

https://dzone.com/articles/java-performance-tuning
http://stackoverflow.com/questions/13855013/understanding-java-memory-management


-- 
Jim Pennino

[toc] | [prev] | [next] | [standalone]

#586777

On Sun, 26 Jun 2016 17:33:19 -0000,
jimp@specsol.spam.sux.com wrote:

> ClutterFreak <ClutterFreak@fakeaddress.com> wrote:
>> On Sun, 26 Jun 2016 04:49:18 -0000,
>> jimp@specsol.spam.sux.com wrote:
>> 
>>>> Thanks god Java programming doesn't deal with memory
>>>> allocation :) The links you provided reminded me of C
>>>> which I left forever with the advent of Java. No
>>>> pointers, no memory allocation / deallocations. Not a
>>>> worry in the world compared to C. In Java such tricky
>>>> nuisances are all taken care of automatically. 
>>> 
>>> If you think Java "doesn't deal with memory allocation", lord help
>>> anyone that runs a program you write.
>> 
>> I said Java programming, not Java. You, the
>> programmer, do not have to deal with memory
>> allocation/deallocation at all. Java takes care of it
>> by itself, and during the program run every now and
>> then checks and deallocates storage places that are
>> not being used anymore. It is all done automatically. 
> 
> Yeah, sure.
> 
> https://dzone.com/articles/java-performance-tuning
> http://stackoverflow.com/questions/13855013/understanding-java-memory-management
> 

These are fine tunings I never had to do. And I doubt
they were available when Java first came out. 

Any programming serious enough has to fine tune memory
management if it's not run on large powerful machines.
I only did serious programming in school and we used
fortran running on machines that could handle any
sloppy memory arrangements. My issues with memory
management began and ended with C. Never had it since. 
--
   "Only he who has learned early to 
    spread his soul out wide may later 
    hold the entire world within himself."

                     - Stefan Zweig


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

[toc] | [prev] | [standalone]

Page 2 of 2 — ← Prev page 1 [2]

Back to top | Article view | sci.physics

csiph-web