/* -*-ePiX-*- */
#include "epix.h"
using namespace ePiX;

const P sz(2,0.25);
const P O(0,0);

int main()
{
  picture(P(0,0), sz, "2.4 x 0.3in");

  begin();

  double rad(0.25), phi(M_PI_4);
  P ctr(1), A(ctr + P(rad)), B(ctr - P(rad)), X(ctr + polar(rad, phi));

  arrow_inset(0.25);
  arrow_width(1.5);

  line(O, P(xmax()));
  arc(ctr, rad, 0, M_PI);
  arc_arrow(ctr, 1.33*rad, M_PI/3, 3*M_PI/4);

  label(O, P(0,-4), "$O$", b);
  label(A, P(0,-4), "$A$", b);
  label(B, P(0,-4), "$B$", b);

  line(ctr, X);
  label(X, P(2,2), "$x$", tr);
  label(0.5*(O+B), P(0,2), "$\\frac{1}{k}$", t);
  label(ctr, P(-2,2), "$1$", t);

  font_size("footnotesize");
  arc_measure(ctr, E_1, cis(phi), P(3,1), "$\\varphi$", r);

  tikz_format();
  end();
}