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% kindofcube.mp
% L. Nobre G.
% 2003
input featpost3Dplus2D;
verbatimtex
\documentclass{article}
\usepackage{beton,concmath,ccfonts}
\begin{document}
etex
Spread := 30;
f := 5.4*(1.5,0.5,1);
beginfig(1);
numeric gridstep, sidenumber, i, j, coord, aa, ab, ac;
color pa;
gridstep = 0.9;
sidenumber = 10;
coord = 0.5*sidenumber*gridstep;
for i=0 upto sidenumber:
for j=0 upto sidenumber:
pa := (-coord+j*gridstep,-coord+i*gridstep,0);
aa := uniformdeviate(360);
ab := uniformdeviate(180);
ac := uniformdeviate(90);
kindofcube( false, false, pa, aa, ab, ac, 0.4, 0.4, 0.9 );
endfor;
endfor;
endfig;
beginfig(2);
f := (4,1.0,0.5);
Spread := 120;
numeric lena, lenb, lenc, aa, ab, ac, angray, micr;
pair zeror;
color axa, axb, axc, returnedcorner, dummyc, auxx, auxy;
lena=0.3;
lenb=0.6;
lenc=0.9;
aa=130;
ab=20;
ac=70;
angray=0.7;
micr=0.01;
zeror=rp(black);
cartaxes(1,1,1);
axa = ( cosd(aa), sind(aa), 0 );
axb = axa*cosd(ab)+blue*sind(ab);
auxx= ( cosd(aa+90), sind(aa+90), 0);
auxy = ncrossprod( axb, auxx );
axc = auxx*cosd(ac)+auxy*sind(ac);
draw zeror--rp(axa);
draw zeror--rp(axb);
draw zeror--rp(-axa);
draw zeror--rp(axc);
draw zeror--rp(auxx);
label.rt( btex $a$ etex, rp(axa) );
label.rt( btex $b$ etex, rp(axb) );
label.lft( btex $c$ etex, rp(auxx) );
label.lft( btex $d$ etex, rp(axc) );
label.bot( btex $o$ etex, zeror );
angline( axa,red,black,angray,btex $\alpha_1$ etex,bot );
angline( axb,axa,black,angray,btex $\alpha_2$ etex,rt );
angline( axc,auxx,black,angray,btex $\alpha_3$ etex,lft );
squareangline( -axa,auxx,black,0.2);
kindofcube( true, true, black, aa, ab, ac, lena, lenb, lenc );
draw zeror--rp(blue) dashed evenly;
dotlabel.bot( btex $l_1$ etex, rp(lena*axb) );
dotlabel.rt( btex $l_2$ etex, rp(lenb*axc) );
dotlabel.top( btex $l_3$ etex, rp(lenc*ncrossprod(axb,axc) ) );
endfig;
verbatimtex
\end{document}
etex
end.
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