22 Aug 2007

Asymptote using geometry.asy – fig0890

Figure 0089
(Compiled with Asymptote version 2.14svn-r5318)
    
import geometry;
size(12cm,0);

// currentcoordsys=cartesiansystem((1,2),i=(1,0.5),j=(-0.5,.75));
show(currentcoordsys, xpen=invisible);

point A=(3.5,0.5);
dot("$A$",A,SW,red);

arc C=arc(ellipse(A,2,1,-30),90,270,fromCenter,CCW);
real l=arclength(C);

draw(C,Arrow);
draw(complementary(C),grey+dashed);
distance("$R=2$",A,point(C.el,0),0);

/* View the definition of point curpoint(arc,real) */
dot("curpoint(C, 0)", curpoint(C,0),E);
dot("curpoint(C, l/4)", curpoint(C,l/4),0.5N+E);
dot("curpoint(C, -l/4)", curpoint(C,-l/4));

dot("curpoint(C, l/2)", point(C,curabscissa(l/2)),W); // point(C,curabscissa(l/2)) is similar to curpoint(C,pi)
dot("curpoint(C, l)", curpoint(C,l), SW);
dot("curpoint(C, 3*l/2)", curpoint(C,3*l/2),E);

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