# ¿Þ£± s0 ¶ÊÌÌ¤È c1 ¶ÊÀþ
TMP1="tmp1$$"
TMP2="tmp2$$"
trap 'rm -f $TMP1 $TMP2; exit 0' 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
/usr/bin/awk '
BEGIN {
  PI = atan2(0, -1)
  PI2 = atan2(0, -1) * 2
  a = 1
  k1 = sqrt(2)
  zmin = 0
#  zmax = zmin + 10
  zmax = zmin + PI2
  dz = (zmax - zmin) / 5
  for (z = 0; z <= zmax; z += dz) {
	for (p = PI; p <= PI2; p += PI / 50) {
		x = a * cos(p)
		y = a * sin(p)
		print x, y, z >"'"$TMP1"'"
	}
	print "\n"  >"'"$TMP1"'"
  }
  for (p = 0; p <= PI2; p += PI / 50) {
	x = a * cos(p)
	y = a * sin(p)
	print x, y, zmax >"'"$TMP1"'"
  }
  print "\n"  >"'"$TMP1"'"
  d = (zmax - zmin) / 50
  for (p = PI; p <= PI2; p += PI/ 10) {
	for (z = zmin; z <= zmax; z += d) {
		x = a * cos(p)
		y = a * sin(p)
		print x, y, z >"'"$TMP1"'"
	}
	print "\n"  >"'"$TMP1"'"
  }
  for (z = zmin; z <= zmax; z += d) {
	p = sqrt(k1^2 - 1)*z/a
	if (k < 0)
		p = -1
	x = a*cos(p)
	y = a*sin(p)
	print x, y, z  >"'"$TMP2"'"
  }
  exit 0
}
END {
  print "set size square 0.5"
  print "set nokey"
  print "set zeroaxis"
  print "set noxtics"
  print "set noytics"
  print "set noztics"
  print "set noborder"
  print "set view 60,0,1"
  print "splot \"'"$TMP1"'\" with lines lc \"red\", \"'"$TMP2"'\" with lines lc \"black\""
  print ""
  exit 0
}
' | gnuplot -persist