On 5/21/2014 7:55 PM, Fabrice Couvreur wrote:
Hi,
As PSTricks (which I prefer) is not yet well integrated, I decided to
learn Metapost starting with a simple code.
\starttext
\startMPcode
numeric xmin, xmax, ymin, ymax;
xmin := -2.5; xmax := 2.5; ymax :=2.5 ;ymin:=-2.5; u := 2cm;
vardef f(expr x) = -x*x+1 enddef;
xinc := 0.001;
path pts_f;
pts_f := (xmin,f(xmin))*u
for x=xmin+xinc step xinc until xmax+xinc:
.. (x,f(x))*u
endfor;
path axe_x,axe_y;
path screen;
screen=(xmin,ymin)*u--(xmax,ymin)*u--(xmax,ymax)*u--(xmin,ymax)*u--cycle;
axe_x = (xmin,0)*u -- (xmax,0)*u;
axe_y = (0,ymin)*u -- (0,ymax)*u;
drawarrow axe_x;
drawarrow axe_y;
draw pts_f withpen pencircle scaled 1;
clip currentpicture to screen;
\stopMPcode
\stoptext
Are there any routines with Metafun to improve this code?
define 'improve' .. anyway:
\starttext
\startMPpage
numeric xmin, xmax, ymin, ymax;
xmin := -2.5; xmax := 2.5; ymax :=2.5 ;ymin:=-2.5; u := 2cm;
pickup pencircle scaled 1pt ;
drawarrow ((xmin,0) -- (xmax,0)) scaled u;
drawarrow ((0,ymin) -- (0,ymax)) scaled u;
draw tightfunction ("x", "-x*x+1", xmin, xmax, (xmax-xmin)/10)
scaled u;
setbounds currentpicture to boundingbox (((xmin,ymin) --
(xmax,ymax)) scaled u);
\stopMPpage
\stoptext
I'm sure that Alan can tell you how to use the new built-in
interpolators, their pros and cons in this case.
Hans
ps. A step of 0.001 is not needed here and gives a pretty large path.
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Hans Hagen | PRAGMA ADE
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