Metapost labeling question. Please help
Hi, I want the labels as (0.5,0.55,0.6,0.65,0.7,...,1) or (0.50,0.55,0.60,0.65,0.70,...,1). Either of these two is fine. I tried the following code for this. \starttext \startuseMPgraphic{labeltest} numeric rmin,rmax; rmin := 0.5; rmax := 1; ux := 25cm; uy :=10cm; % draw axes draw (rmin,0)*ux -- (rmax+0.1,0)*ux; draw (rmin,0)*ux -- (rmin*ux,(1.1)*uy); for x = 0.5 step 0.05 until 1.1: label.bot(textext(decimal(x)),(x*ux,x*uy)); endfor; \stopuseMPgraphic \useMPgraphic{labeltest} \stoptext I get (0.5,0.55, 0.6,0.65001,0.70001,0.75002,...,1.00003) instead. I don't understand why I get more than 2 digits after 0.6. Is there a way to restrict the number of digits after the decimal point. Thanks very much.
On Fri, Apr 3, 2009 at 03:02, Curiouslearn wrote:
Hi, I want the labels as (0.5,0.55,0.6,0.65,0.7,...,1) or (0.50,0.55,0.60,0.65,0.70,...,1). Either of these two is fine. I tried the following code for this. \starttext \startuseMPgraphic{labeltest} numeric rmin,rmax; rmin := 0.5; rmax := 1; ux := 25cm; uy :=10cm; % draw axes draw (rmin,0)*ux -- (rmax+0.1,0)*ux; draw (rmin,0)*ux -- (rmin*ux,(1.1)*uy); for x = 0.5 step 0.05 until 1.1: label.bot(textext(decimal(x)),(x*ux,x*uy)); endfor; \stopuseMPgraphic \useMPgraphic{labeltest} \stoptext I get (0.5,0.55, 0.6,0.65001,0.70001,0.75002,...,1.00003) instead. I don't understand why I get more than 2 digits after 0.6.
It's because you get exact numbers in the terms what metapost considers exact (multiples of 2^{-something}). You have exactly the same problem if you work with floating points with any other programming language.
Is there a way to restrict the number of digits after the decimal point. Thanks very much.
See page 18 of metapost manual (speaking of metapost manual present in TeX Live): ----- 6.2 Operators The length operator returns the number of characters in a string. For substring construction, the ⟨of operator⟩ substring is used like this: substring ⟨pair expression⟩ of ⟨string primary⟩ substring (2,4) of "abcde" is "cd". ----- You can use substring (0,4) to truncate the number. 0.5 might need special treatment, so you either need to concatenate it with 0 at the end or you need to check the lenght of string before using substring. Mojca
Curiouslearn schrieb:
Hi,
I want the labels as (0.5,0.55,0.6,0.65,0.7,...,1) or (0.50,0.55,0.60,0.65,0.70,...,1). Either of these two is fine.
I tried the following code for this.
\starttext
\startuseMPgraphic{labeltest} numeric rmin,rmax; rmin := 0.5; rmax := 1; ux := 25cm; uy :=10cm; % draw axes draw (rmin,0)*ux -- (rmax+0.1,0)*ux; draw (rmin,0)*ux -- (rmin*ux,(1.1)*uy); for x = 0.5 step 0.05 until 1.1: label.bot(textext(decimal(x)),(x*ux,x*uy)); you accumulate the rounding error with every step of the loop. try to avoid such 'low value' steps if possible.
for x = 10 step 1 until 22: % 0.05*20 to get an integer loop index tx := x/20; % correct value label.bot(textext(decimal(tx)),(tx*ux,tx*uy)); Best wishes, Peter
endfor; \stopuseMPgraphic
\useMPgraphic{labeltest}
\stoptext
I get (0.5,0.55, 0.6,0.65001,0.70001,0.75002,...,1.00003) instead. I don't understand why I get more than 2 digits after 0.6. Is there a way to restrict the number of digits after the decimal point.
Thanks very much.
------------------------------------------------------------------------
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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://tex.aanhet.net archive : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net ___________________________________________________________________________________
-- "Es ist doch ein Trost, das Geldgier manchmal blöd macht." - Kottan in "Kottan ermittelt", Folge 9: "Die Einteilung" -
Mojca and Peter, thanks very much for your responses. I used Peter's
solution and it worked beautifully.
Does anyone know how I can change the size of these labels? If I try
textext(\tfa decimal(tx))
that does not work.
On Fri, Apr 3, 2009 at 6:52 AM, Peter Rolf
Curiouslearn schrieb:
Hi,
I want the labels as (0.5,0.55,0.6,0.65,0.7,...,1) or (0.50,0.55,0.60,0.65,0.70,...,1). Either of these two is fine.
I tried the following code for this.
\starttext
\startuseMPgraphic{labeltest} numeric rmin,rmax; rmin := 0.5; rmax := 1; ux := 25cm; uy :=10cm; % draw axes draw (rmin,0)*ux -- (rmax+0.1,0)*ux; draw (rmin,0)*ux -- (rmin*ux,(1.1)*uy); for x = 0.5 step 0.05 until 1.1: label.bot(textext(decimal(x)),(x*ux,x*uy));
you accumulate the rounding error with every step of the loop. try to avoid such 'low value' steps if possible.
for x = 10 step 1 until 22: % 0.05*20 to get an integer loop index tx := x/20; % correct value label.bot(textext(decimal(tx)),(tx*ux,tx*uy));
Best wishes, Peter
endfor;
\stopuseMPgraphic
\useMPgraphic{labeltest}
\stoptext
I get (0.5,0.55, 0.6,0.65001,0.70001,0.75002,...,1.00003) instead. I don't understand why I get more than 2 digits after 0.6. Is there a way to restrict the number of digits after the decimal point. Thanks very much.
------------------------------------------------------------------------
___________________________________________________________________________________ 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 : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net
___________________________________________________________________________________
-- "Es ist doch ein Trost, das Geldgier manchmal blöd macht."
- Kottan in "Kottan ermittelt", Folge 9: "Die Einteilung" -
___________________________________________________________________________________ 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 : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net
___________________________________________________________________________________
Am 03.04.2009 um 14:47 schrieb Curiouslearn:
Mojca and Peter, thanks very much for your responses. I used Peter's solution and it worked beautifully.
Does anyone know how I can change the size of these labels? If I try
textext(\tfa decimal(tx))
textext("\tfa" & decimal(tx)) Wolfgang
Beautiful! Thanks, Wolfgang. On Fri, Apr 3, 2009 at 9:35 AM, Wolfgang Schuster < schuster.wolfgang@googlemail.com> wrote:
Am 03.04.2009 um 14:47 schrieb Curiouslearn:
Mojca and Peter, thanks very much for your responses. I used Peter's
solution and it worked beautifully.
Does anyone know how I can change the size of these labels? If I try
textext(\tfa decimal(tx))
textext("\tfa" & decimal(tx))
Wolfgang
___________________________________________________________________________________ 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 : https://foundry.supelec.fr/projects/contextrev/ wiki : http://contextgarden.net
___________________________________________________________________________________
participants (4)
-
Curiouslearn -
Mojca Miklavec -
Peter Rolf -
Wolfgang Schuster