Re: [NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-25 Thread Curiouslearn 
Taco, thanks for the suggestions. I will try using intersectiontimes.
It would be great if, as you said, this is solved with Metapost 2.0.

Any idea when that version is coming out?

Thanks.

On Wed, Nov 25, 2009 at 2:47 AM, Taco Hoekwater t...@elvenkind.com wrote:
 Taco Hoekwater wrote:

 The solution is to add an explicit fix to Lint[4] just after its
 current assignment:

    Lint[4]:=(xpart Lint[4], 0);

 Even better is to not use intersectionpoint at all: use
 intersectiontimes instead. With that, you can select a point
 that is guaranteed to be on one of the two paths.

 Best wishes,
 Taco
 ___
 If your question is of interest to others as well, please add an entry to
 the Wiki!

 maillist : ntg-context@ntg.nl /
 http://www.ntg.nl/mailman/listinfo/ntg-context
 webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
 archive  : http://foundry.supelec.fr/projects/contextrev/
 wiki     : http://contextgarden.net
 ___

___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___

Re: [NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-25 Thread Taco Hoekwater 

Curiouslearn wrote:

Taco, thanks for the suggestions. I will try using intersectiontimes.
It would be great if, as you said, this is solved with Metapost 2.0.

Any idea when that version is coming out?


Next summer
___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___

[NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-24 Thread Curiouslearn 
The code below shows a cyclic path that I am interested in creating
(it is in red if you run the code). The example works fine as long as
I have, u:=1cm, as in the code below. But if I replace it by ,
u:=0.6cm, there is no output. There is an error saying that paths 4
and 3 do not intersect. Is this a bug?

Thanks for your help.

\setuppapersize[letter][letter]
\setuplayout[leftedge=0in,leftmargin=1in,leftmargindistance=0in,rightmargin=1in,rightmargindistance=0in,rightedge=0in,leftedgedistance=0in,rightedgedistance=0in,topspace=0.5in,width=6.5in,height=10in]

\setupcolors[state=start]


\starttext

\startuseMPgraphic{buildS22}
numeric u;
u := 1cm;
w:= 2pt;
path xaxis; path yaxis;
xaxis := (0,0)--(12,0) scaled u;
yaxis := (0,0)--(0,12) scaled u;
path stLine;
path Curve;
stLine :=
function (1,x,10-x,0,10,1) scaled u;
Curve :=
function(1,x,2+8/x,1,10,0.1) scaled u;
drawarrow xaxis withpen pencircle scaled w;
drawarrow yaxis withpen pencircle scaled w; 
draw stLine withpen pencircle scaled w withcolor 0.5red;
draw Curve withpen pencircle scaled w withcolor 0.5green;
pair Lint[];
Lint[1]:=yaxis intersectionpoint stLine;
Lint[2]:=stLine intersectionpoint Curve;
Lint[3]:=reverse stLine intersectionpoint Curve;
Lint[4]:=stLine intersectionpoint xaxis;
path cyclicPath;
cyclicPath := buildcycle(Lint[1]--Lint[2],Curve,Lint[3]--Lint[4],reverse
xaxis,yaxis);
draw cyclicPath withpen pencircle scaled 5pt withcolor red;
\stopuseMPgraphic
\useMPgraphic{buildS22}

\stoptext
___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___

Re: [NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-24 Thread luigi scarso 
On Wed, Nov 25, 2009 at 5:45 AM, Curiouslearn curiousle...@gmail.com wrote:
 The code below shows a cyclic path that I am interested in creating
 (it is in red if you run the code). The example works fine as long as
 I have, u:=1cm, as in the code below. But if I replace it by ,
 u:=0.6cm, there is no output. There is an error saying that paths 4
 and 3 do not intersect. Is this a bug?

 Thanks for your help.

 \setuppapersize[letter][letter]
 \setuplayout[leftedge=0in,leftmargin=1in,leftmargindistance=0in,rightmargin=1in,rightmargindistance=0in,rightedge=0in,leftedgedistance=0in,rightedgedistance=0in,topspace=0.5in,width=6.5in,height=10in]

 \setupcolors[state=start]


 \starttext

 \startuseMPgraphic{buildS22}
        numeric u;
        u := 1cm;
        w:= 2pt;
        path xaxis; path yaxis;
        xaxis := (0,0)--(12,0) scaled u;
        yaxis := (0,0)--(0,12) scaled u;
        path stLine;
        path Curve;
        stLine :=
                        function (1,x,10-x,0,10,1) scaled u;
        Curve :=
                        function(1,x,2+8/x,1,10,0.1) scaled u;
        drawarrow xaxis withpen pencircle scaled w;
        drawarrow yaxis withpen pencircle scaled w;
        draw stLine withpen pencircle scaled w withcolor 0.5red;
        draw Curve withpen pencircle scaled w withcolor 0.5green;
        pair Lint[];
        Lint[1]:=yaxis intersectionpoint stLine;
        Lint[2]:=stLine intersectionpoint Curve;
        Lint[3]:=reverse stLine intersectionpoint Curve;
        Lint[4]:=stLine intersectionpoint xaxis;
        path cyclicPath;
        cyclicPath := 
 buildcycle(Lint[1]--Lint[2],Curve,Lint[3]--Lint[4],reverse
 xaxis,yaxis);
        draw cyclicPath withpen pencircle scaled 5pt withcolor red;
 \stopuseMPgraphic
 \useMPgraphic{buildS22}

 \stoptext
 ___
 If your question is of interest to others as well, please add an entry to the 
 Wiki!

 maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
 webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
 archive  : http://foundry.supelec.fr/projects/contextrev/
 wiki     : http://contextgarden.net
 ___

hm..
can you try  with
  tracingall;
  cyclicPath :=
buildcycle(Lint[1]--Lint[2],Curve,Lint[3]--Lint[4],reverse
xaxis,yaxis);

?
-- 
luigi
___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___

Re: [NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-24 Thread Taco Hoekwater 

luigi scarso wrote:

On Wed, Nov 25, 2009 at 5:45 AM, Curiouslearn curiousle...@gmail.com wrote:

The code below shows a cyclic path that I am interested in creating
(it is in red if you run the code). The example works fine as long as
I have, u:=1cm, as in the code below. But if I replace it by ,
u:=0.6cm, there is no output. There is an error saying that paths 4
and 3 do not intersect. Is this a bug?


More a 'known limitation': intersection point calculations are not
perfect because of the fixed precision calculus.

Lint[4] is the culprit. With u=0.6cm it has these coordinates:
(170.07976,0.00014). Notice how the y coordinate is not actually
on the xaxis? That is because the actual intersection between
stLine and xaxis does not fit nicely into a scaled pair, so
metapost takes the 'closest approximation', which in this case
is slightly off both lines.

The solution is to add an explicit fix to Lint[4] just after its
current assignment:

Lint[4]:=(xpart Lint[4], 0);

This is not pretty, and one of the problems we hope to solve
with metapost 2.0.

Best wishes,
Taco
___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___

Re: [NTG-context] Metapost - Seems like weird behavior. Is it a bug?

2009-11-24 Thread Taco Hoekwater 

Taco Hoekwater wrote:


The solution is to add an explicit fix to Lint[4] just after its
current assignment:

Lint[4]:=(xpart Lint[4], 0);


Even better is to not use intersectionpoint at all: use
intersectiontimes instead. With that, you can select a point
that is guaranteed to be on one of the two paths.

Best wishes,
Taco
___
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___