Hello mr. art

Thanks for replying.

Right now I did try to replace the s with other
variable names, but it didn't stop those ever-
changing error messages.

I'm just using plain POV-Ray (v3.1g) for Windows 
(Not MegaPOV).

I looked up reserved identifiers and keywords in
the help file, but I could not find 's' listed 
for this plain version of POV-Ray.

Regards

Tor Olav

mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html


"mr.art" wrote:
> 
> I know that these are not directly part of the problem,
> but, s seems to be flagged as a reserved word in MegaPOV.
> 
> Tor Olav Kristensen wrote:
> >
> > Hello
> >
> > I'm trying to make some macros to enable me to
> > experiment with different rotation matrix's. (That I
> > later will apply to 3D vectors to get the desired
> > rotation of the vector.)
> >
> ><snip>
> >
> > #macro Mscale(s, MM)
> >
> >   #local NN = array[3]
> >   #local NN[0] = s*MM[0];
> >   #local NN[1] = s*MM[1];
> >   #local NN[2] = s*MM[2];
> >
> >   MM
> >
> > #end
> >
> > #macro Minv(MM)
> >
> >   #local NN = array[3]
> >   #local PP = array[3]
> >   #local QQ = array[3]
> >   #local s = 1/Mdet(MM);
> >   #local NN = Mcof(MM)
> >   #local PP = Mtrans(NN)
> >   #local QQ = Mscale(s, PP)
> >
> >   QQ
> >
> > #end
> 
> --
> Mr. Art
> 
> "Often the appearance of reality is more important
> than the reality of the appearance."
> Bill DeWitt 2000

Post a reply to this message

Tor Olav Kristensen wrote:
> 
> My problem is that I get several different error
> messages when I try to Run the file below in this
> message (I did not alter it between the Runs).

I have sometimes gotten error messages that seemed like the
wrong error message.  If I recall correctly, it turned out that
the actual error was at some point earlier than what the parser
flagged.

-- 
ICQ: 46085459

Post a reply to this message

Tor Olav Kristensen wrote:
> 
> Hello
> 
Hello. 

Just a thought: try to add semicolons to lines, where they are
missing...

Post a reply to this message

Hello John

I too have got error messages pointing to the 
wrong point in my code when my error(s) were 
hidden somewhere earlier.

In these cases I just had to start commenting 
out code, changing variable names and moving 
things around until the error messages points 
at my real error.

I suspect that this may also be the case here,
and I have therefore tried to play around with 
my code before posting to this newsgroup... But 
I haven't had any luck smoking out my(?) errors 
yet.

But I have found out that if I replace the last 
line of these four:

#declare QQi = array[3]
#declare QQi = Minv(MMi) 

#declare RRi = array[3]
#declare RRi = Mmult(MMi, Minv(MMi))

with 

#declare RRi = Mmult(MMi, QQi)

then the error messages disappear.

This may be my solution for this time, but the 
problem still bothers me, because I want to be 
able to replace macros like e.g. this one:

#macro Minv(MM)

  #local NN = array[3]
  #local PP = array[3]
  #local QQ = array[3]
  #local s = 1/Mdet(MM); 
  #local NN = Mcof(MM) 
  #local PP = Mtrans(NN)
  #local QQ = Mscale(s, PP) 

  QQ

#end

with macors like this one:

#macro Minv(MM)

  Mscale(1/Mdet(MM), Mtrans(Mcof(MM))) 

#end

Lately I have also found that it seems that 
the more I do of the substitutions like the 
one above, the more it seems likely that I 
start getting those random changing error 
messages I have described earlier.

(It seems like I can do some substitutions 
without being punished.)

And now I don't know how to proceed in my 
hunt for these errors.

Am I the only one who is getting changing 
error messages when running the code I 
enclosed in my initial posting?

Regards

Tor Olav

mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

John VanSickle wrote:
> 
> Tor Olav Kristensen wrote:
> >
> > My problem is that I get several different error
> > messages when I try to Run the file below in this
> > message (I did not alter it between the Runs).
> 
> I have sometimes gotten error messages that seemed like the
> wrong error message.  If I recall correctly, it turned out that
> the actual error was at some point earlier than what the parser
> flagged.
> 
> --
> ICQ: 46085459

Post a reply to this message

Hi Vahur

Vahur Krouverk wrote:
> 
> Tor Olav Kristensen wrote:
> >
> > Hello
> >
> Hello.
> 
> Just a thought: try to add semicolons to lines, where they are
> missing...

Hmm...

I have been a little bit worried about my use of semicolons.

Earlier I have seen that too many missing semicolons can 
cause crashes of POV-Ray (on my Windows 98 machine at home, 
and if I remember right, also on my Windows NT4 machine at 
work).

Therefore I have looked through my code to make sure that I 
had put them where I thought they should be.

But your reply (thank you btw.) made me check both my code 
and the help file once again. 

Here are my (rather lengthy) findings:

When POV-Ray parses my file, I do not get any warning 
messages like this one:

warning: All #versions and #declares of float, vector, and 
color require semi-colon ';' at end.

So everything apparently looked fine, but I thought that
maybe my array declarations should have some semi-colons as 
well (even if array declarations aren't mentioned in 
messages like the one above.)

In the help file for Windows didn't have any luck finding
explicit instructions about whether I should use semi-colons
after array declarations or not.

But I found two code examples of array declarations:

The first one 

8< snip
 #declare MyArray = array[10];
 #declare MyArray[5] = pigment{White}  //all other elements must be
                     //pigments too.
8< snip

used semi-colon, and the second one

8< snip
 #declare MyArray = array[10]
 #declare MyGrid = array[4][5]
 #declare YourArray = MyArray  //this is ok
8< snip

did not.

So now I thought that I should try to insert some of them 
after my array declarations.

So I did, but now the parser started complaining about these 
semi-colons:

#declare NNi = array[3]; <----ERROR
error: object or directive expected but ; found instead.

... So now I am totally confused about semi-colons!

;(

Regards

Tor Olav

-- 
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

Post a reply to this message

Tor Olav Kristensen wrote:
> 
> I have been a little bit worried about my use of semicolons.
> 
> Earlier I have seen that too many missing semicolons can
> cause crashes of POV-Ray (on my Windows 98 machine at home,
> and if I remember right, also on my Windows NT4 machine at
> work).

This is new to me. You mean the machine crached? Or just POV quit parsing?
Usually, missing semi-colons should only produce warnings (at least in the
current version). Only in some macros have I seen actual errors caused by them.

> ... So now I am totally confused about semi-colons!
> 

Semi-colons should only go after declarations of floats and vectors (colours can
also be thought of as vectors).
If you are declaring an array, it should not have a semi-colon:

#declare MyArray=array[10]

If the docs said otherwse, this is a typo. However, if you are declaring an
element of an array, and that element is a float or a vector, it should have a
semi-colon:

#declare MyArray[0]=11.5;

See docs section "Declaring identifiers" for further reference.

Margus

Post a reply to this message

Tor Olav Kristensen wrote:
> 
> Hello John
> 
> I too have got error messages pointing to the
> wrong point in my code when my error(s) were
> hidden somewhere earlier.
> 
> In these cases I just had to start commenting
> out code, changing variable names and moving
> things around until the error messages points
> at my real error.
> 
> I suspect that this may also be the case here,
> and I have therefore tried to play around with
> my code before posting to this newsgroup... But
> I haven't had any luck smoking out my(?) errors
> yet.
> 
> But I have found out that if I replace the last
> line of these four:
> 
> #declare QQi = array[3]
> #declare QQi = Minv(MMi)
> 
> #declare RRi = array[3]
> #declare RRi = Mmult(MMi, Minv(MMi))
> 
> with
> 
> #declare RRi = Mmult(MMi, QQi)
> 
> then the error messages disappear.

There appears to be a bug in macro argument parsing.  Sometimes when
I #declare a value using a macro, the semicolon at the end of the
declare statement is flagged as an error, and when it's absent a
warning message is displayed.

Regards,
John
-- 
ICQ: 46085459

Post a reply to this message

Margus Ramst wrote:
> 
> Tor Olav Kristensen wrote:
> >
> > I have been a little bit worried about my use of semicolons.
> >
> > Earlier I have seen that too many missing semicolons can
> > cause crashes of POV-Ray (on my Windows 98 machine at home,
> > and if I remember right, also on my Windows NT4 machine at
> > work).
> 
> This is new to me. You mean the machine crached? Or just POV quit parsing?
> Usually, missing semi-colons should only produce warnings (at least in the
> current version). Only in some macros have I seen actual errors caused by them.
> 

I mean that as far as I remember, POV-Ray stopped executing and Windows 
gave me an error message like: 

This application has performed an illegal operation...

(When I restarted POV-Ray, reloaded the offending POV-file and tried 
to run it again, I got the same crash. And when I thereafter added all
the 
necessary semi-colons POV-Ray executed correctly again.)

Earlier I had not got used to typing semi-colons at the end of float 
and vector declarations, so I saw these error messages once or twice a 
month or so, but now I usually forget very few of the semi-colons, so I 
seldom see these crashes.

If it happens again I will provide you with the offending POV-file.


Btw. Do you have any idea of how POV-Ray manage to give me several 
different error messages after successive runs (without me altering 
my code or any settings in POV-Ray) ?

For me this seems like POV-Ray is in error ...

(Or could my error trigger several error messages, where only a 
random selected one is printed each time?)

The funny thing is that none of the keywords ('clock_delta', 'tan', 
'on') that POV-Ray claims it found in a wrong place, appears in my 
POV-file. 

error: undeclared identifier expected but float function 'clock_delta' 
found instead.

> > ... So now I am totally confused about semi-colons!
> >
> 
> Semi-colons should only go after declarations of floats and vectors (colours can
> also be thought of as vectors).
> If you are declaring an array, it should not have a semi-colon:
> 
> #declare MyArray=array[10]
> 
> If the docs said otherwse, this is a typo. However, if you are declaring an
> element of an array, and that element is a float or a vector, it should have a
> semi-colon:
> 

Thanks for clarifying!

> #declare MyArray[0]=11.5;
> 
> See docs section "Declaring identifiers" for further reference.
> 
> Margus


Regards

Tor Olav

-- 
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

Post a reply to this message

In article <38D04348.E90DFF94@hotmail.com>, Tor Olav Kristensen 
<tor### [at] hotmailcom> wrote:

> Earlier I had not got used to typing semi-colons at the end of float 
> and vector declarations, so I saw these error messages once or twice a 
> month or so, but now I usually forget very few of the semi-colons, so I 
> seldom see these crashes.

I really wish POV-Ray would accept, if not require, semicolons at the 
end of declarations. It should be a simple modification to make, at 
least for someone who understands the declaration code(I don't).


> Btw. Do you have any idea of how POV-Ray manage to give me several 
> different error messages after successive runs (without me altering 
> my code or any settings in POV-Ray) ?
> 
> For me this seems like POV-Ray is in error ...
> 
> (Or could my error trigger several error messages, where only a 
> random selected one is printed each time?)
> 
> The funny thing is that none of the keywords ('clock_delta', 'tan', 
> 'on') that POV-Ray claims it found in a wrong place, appears in my 
> POV-file. 
> 
> error: undeclared identifier expected but float function 'clock_delta' 
> found instead.

It sounds like POV is using(internally, not in your scene) a variable 
that doesn't get initialized...this would qualify as a bug even if that 
isn't the cause.

-- 
Chris Huff
e-mail: chr### [at] yahoocom
Web page: http://chrishuff.dhs.org/

Post a reply to this message

Chris Huff wrote:

> I really wish POV-Ray would accept, if not require, semicolons at the
> end of declarations. It should be a simple modification to make, at
> least for someone who understands the declaration code(I don't).

Why ?

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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