POV-Ray : Newsgroups : povray.binaries.scene-files : Simulated urbanism macro scene: version 2013.04.08 Server Time
28 Mar 2024 04:44:10 EDT (-0400)
  Simulated urbanism macro scene: version 2013.04.08 (Message 1 to 8 of 8)  
From: Thomas de Groot
Subject: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 04:00:40
Message: <51627928@news.povray.org>
I made a number of code improvements to the macros, following 
Christian's advice.

In the Orientation() macro I also changed the #while() loop into a 
#for() loop.

I have a major question though.

If, in the Urbanism() macro, I change the #while() into a #for() loop, I 
get a different end result! IMO this should not be the case as no 
changes whatsoever are made to any random parameter. You can test this 
yourself by:

1) change the line:
   #while (Counter < Numbers)
into:
   #for (Counter, 1, Numbers)

and 2) comment out the line: #local Counter = Counter + 1;

A second question follows from the docs about the #for() loop (my italics):
[quote]
A new #for loop construct is now available for simple loops incrementing 
Identifier from Start to End /(inclusive)/ with the given Step size. The 
default Step size is +1.0.
[/quote]

However, in the code and setting Verbose=on, #for() goes till End-1.

Probably my skull thickness but any idea?

Thomas


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From: nimda
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 09:40:01
Message: <web.5162c800e84780e6787874620@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> I made a number of code improvements to the macros, following
> Christian's advice.
>
> In the Orientation() macro I also changed the #while() loop into a
> #for() loop.
>
> I have a major question though.
>
> If, in the Urbanism() macro, I change the #while() into a #for() loop, I
> get a different end result! IMO this should not be the case as no
> changes whatsoever are made to any random parameter. You can test this
> yourself by:
>
> 1) change the line:
>    #while (Counter < Numbers)
> into:
>    #for (Counter, 1, Numbers)
>
> and 2) comment out the line: #local Counter = Counter + 1;
>
> A second question follows from the docs about the #for() loop (my italics):
> [quote]
> A new #for loop construct is now available for simple loops incrementing
> Identifier from Start to End /(inclusive)/ with the given Step size. The
> default Step size is +1.0.
> [/quote]
>
> However, in the code and setting Verbose=on, #for() goes till End-1.
>
> Probably my skull thickness but any idea?
>
> Thomas

IMHO the #for loop goes to the end value if reaches it e.g.:
#for (I, 1, 10)
#warning Str(I)
#end
will show all the numbers from 1 up to 10, but  :
#for (I, 1, 10, 2)
#warning Str(I)
#end
will only show 1, 3, 5, 7, 9 because the 11 that follows is greater than 10.

On the other hand a #while (I<10) statement will only show the numbers up to 9
because the symbol "<" means *strictly* smaller than. If you want 10 to show up
you should use #while (I<=10).

regards,

Marc


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From: Thomas de Groot
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 10:17:36
Message: <5162d180$1@news.povray.org>
On 8-4-2013 15:38, nimda wrote:
> IMHO the #for loop goes to the end value if reaches it e.g.:
> #for (I, 1, 10)
> #warning Str(I)
> #end
> will show all the numbers from 1 up to 10, but  :
> #for (I, 1, 10, 2)
> #warning Str(I)
> #end
> will only show 1, 3, 5, 7, 9 because the 11 that follows is greater than 10.

Yes. However, in my code #for (Counter, 1, 10) with default step=1, the 
Counter only shows the numbers 1 to 9...
I am sure I am missing something obvious here :-(

>
> On the other hand a #while (I<10) statement will only show the numbers up to 9
> because the symbol "<" means *strictly* smaller than. If you want 10 to show up
> you should use #while (I<=10).

Of course, but there lies not my problem.

Thomas


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From: Thomas de Groot
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 10:40:14
Message: <5162d6ce@news.povray.org>
On 8-4-2013 16:17, Thomas de Groot wrote:

> Yes. However, in my code #for (Counter, 1, 10) with default step=1, the
> Counter only shows the numbers 1 to 9...
> I am sure I am missing something obvious here :-(

More bizarre than that: #for(Counter, 1, Numbers) where Numbers=50  the 
last number shown is 49, but for all other values (as far as I have 
tested now) the result is correct. Have I met a freakish behaviour just 
by chance? Something to do with rounding effect?

Thomas


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From: nimda
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 15:00:01
Message: <web.516312fbe84780e6787874620@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> On 8-4-2013 16:17, Thomas de Groot wrote:
>
> > Yes. However, in my code #for (Counter, 1, 10) with default step=1, the
> > Counter only shows the numbers 1 to 9...
> > I am sure I am missing something obvious here :-(
>
> More bizarre than that: #for(Counter, 1, Numbers) where Numbers=50  the
> last number shown is 49, but for all other values (as far as I have
> tested now) the result is correct. Have I met a freakish behaviour just
> by chance? Something to do with rounding effect?
>
> Thomas

What messages do you get when you do the following:

#for (I, 1, 10)
#warning Str(I)
#end

Or does the Counter gets modified during the loop?

Marc


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From: clipka
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 8 Apr 2013 17:57:18
Message: <51633d3e@news.povray.org>
Am 08.04.2013 16:40, schrieb Thomas de Groot:
> On 8-4-2013 16:17, Thomas de Groot wrote:
>
>> Yes. However, in my code #for (Counter, 1, 10) with default step=1, the
>> Counter only shows the numbers 1 to 9...
>> I am sure I am missing something obvious here :-(
>
> More bizarre than that: #for(Counter, 1, Numbers) where Numbers=50  the
> last number shown is 49, but for all other values (as far as I have
> tested now) the result is correct. Have I met a freakish behaviour just
> by chance? Something to do with rounding effect?

Can't confirm that one. Are you computing Numbers somehow? Maybe due to 
rounding effects you end up with Numbers = 49.9999 or some such.


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From: Thomas de Groot
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 9 Apr 2013 03:19:11
Message: <5163c0ef$1@news.povray.org>
To nimda and Clipka:

I got it! :-)

The #for() loop definitely does *not* work correctly for my particular 
case, while the #while() loop does. The reason is that Counter should 
only be incremented *if* the #inside() test is passed as negative (not 
inside object). With the #for() loop, Counter is *always* incremented 
whatever the result of the #inside() test.

Conclusion: I should use the #while() loop in this case as easiest 
coding procedure.

My first question about the different results in placing houses is now 
also answered. It derives from the above of course.

Thomas


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From: clipka
Subject: Re: Simulated urbanism macro scene: version 2013.04.08
Date: 9 Apr 2013 04:04:41
Message: <5163cb99@news.povray.org>
Am 09.04.2013 09:19, schrieb Thomas de Groot:
>
> I got it! :-)
>
> The #for() loop definitely does *not* work correctly for my particular
> case, while the #while() loop does. The reason is that Counter should
> only be incremented *if* the #inside() test is passed as negative (not
> inside object). With the #for() loop, Counter is *always* incremented
> whatever the result of the #inside() test.

Yeah, that /could/ make a difference ;-)


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