design/boxalign.py

   1 #!/usr/bin/env python
   2 import sys, math
   3 sys.path[:0] = [".."]
   4 from pyx import *
   5
   6 c = canvas.canvas()
   7 c.stroke(path.line(0, 0, 4, 2), deco.earrow.Large())
   8 t = text.text(2, 1, r"$\vec p$")
   9 t.linealign(0.1, -2/math.sqrt(20), 4/math.sqrt(20))
  10 c.insert(t)
  11 c.stroke(path.line(0, 0, 1, 1), deco.earrow.Large())
  12 t = text.text(0.5, 0.5, r"$\vec a$")
  13 t.linealign(0.1, -1/math.sqrt(2), 1/math.sqrt(2))
  14 c.insert(t)
  15 c.stroke(path.line(-1, 3, 3, -1), style.linestyle.dotted)
  16 c.stroke(path.line(1, 1, 1-1/math.sqrt(2), 1+1/math.sqrt(2)), deco.earrow.Large())
  17 t = text.text(1-1/math.sqrt(8), 1+1/math.sqrt(8), r"$\vec b$")
  18 t.linealign(0.1, 1/math.sqrt(2), 1/math.sqrt(2))
  19 c.insert(t)
  20 c.writetofile("boxalignpal")
  21
  22 ###############################################################################
  23
  24 c = canvas.canvas()
  25 c.stroke(path.line(0, 0, 4, 2), deco.earrow.Large())
  26 t = text.text(2, 1, r"$\vec p$")
  27 t.linealign(0.1, -2/math.sqrt(20), 4/math.sqrt(20))
  28 c.insert(t)
  29 c.stroke(path.line(0, 0, -1, 1), deco.earrow.Large())
  30 t = text.text(-0.5, 0.5, r"$\vec a$")
  31 t.linealign(0.1, -1/math.sqrt(2), -1/math.sqrt(2))
  32 c.insert(t)
  33 c.stroke(path.path(path.arc(0, 0, math.sqrt(2), 0, 360), path.closepath()), style.linestyle.dotted)
  34 c.writetofile("boxalignpac")
  35
  36 ###############################################################################
  37
  38 c = canvas.canvas()
  39 c.stroke(path.line(0, 0, 4, 2), deco.earrow.Large())
  40 t = text.text(2, 1, r"$\vec e$")
  41 t.linealign(0.1, -2/math.sqrt(20), 4/math.sqrt(20))
  42 c.insert(t)
  43 c.stroke(path.line(0, 0, 6, 2), deco.earrow.Large())
  44 t = text.text(3, 1, r"$\vec f$")
  45 t.linealign(0.1, 2/math.sqrt(60), -6/math.sqrt(60))
  46 c.insert(t)
  47 c.stroke(path.line(6, 2, 4, 2), deco.earrow.Large())
  48 t = text.text(5, 2, r"$\vec g$")
  49 t.linealign(0.1, 0, 1)
  50 c.insert(t)
  51 c.stroke(path.line(0, 0, -1, 1), deco.earrow.Large())
  52 t = text.text(-0.5, 0.5, r"$\vec a$")
  53 t.linealign(0.1, -1/math.sqrt(2), -1/math.sqrt(2))
  54 c.insert(t)
  55 c.stroke(path.path(path.arc(0, 0, math.sqrt(2), 0, 360), path.closepath()), style.linestyle.dotted)
  56 c.stroke(path.line(0, 0, 0, math.sqrt(2)), deco.earrow.Large())
  57 t = text.text(0, 1/math.sqrt(2), r"$\vec b$")
  58 t.linealign(0.1, -1, 0)
  59 c.insert(t)
  60 c.writetofile("boxalignlac")
  61
  62 ###############################################################################
  63
  64 def drawexample(canvas, corner, linealign):
  65     r = 1.5
  66     canvas.stroke(path.path(path.arc(0, 0, r, 0, 360)))
  67     phi = 0
  68     while phi < 2 * math.pi + 1e-10:
  69         if corner:
  70             b = box.polygon(center=(0, 0), corners=[(0, 0), (1, 0), (0.5, math.sqrt(3)/2)])
  71         else:
  72             b = box.polygon(center=(0, 0), corners=[(-0.5, -math.sqrt(3)/6), (0.5, -math.sqrt(3)/6), (0, math.sqrt(3)/3)])
  73         if linealign:
  74             b.linealign(r, math.cos(phi), math.sin(phi))
  75         else:
  76             b.circlealign(r, math.cos(phi), math.sin(phi))
  77         if round(phi / math.pi * 2 * 100) % 100:
  78             canvas.stroke(b.path())
  79         else:
  80             canvas.stroke(b.path(), color.rgb.red)
  81         phi += math.pi / 50
  82
  83 d = 6
  84 c = canvas.canvas()
  85 sc = c.insert(canvas.canvas(trafo.translate(0, d)))
  86 drawexample(sc, 0, 0)
  87 sc = c.insert(canvas.canvas(trafo.translate(d, d)))
  88 drawexample(sc, 0, 1)
  89 sc = c.insert(canvas.canvas(trafo.translate(0, 0)))
  90 drawexample(sc, 1, 0)
  91 sc = c.insert(canvas.canvas(trafo.translate(d, 0)))
  92 drawexample(sc, 1, 1)
  93 c.text(0, 1.5*d, "align at a circle", text.halign.center)
  94 c.text(d, 1.5*d, "align at tangents", text.halign.center)
  95 c.text(-0.5*d, d, "reference point at the triangle center", text.halign.center, trafo.rotate(90))
  96 c.text(-0.5*d, 0, "reference point at a triangle corner", text.halign.center, trafo.rotate(90))
  97 c.writetofile("boxalignexample")
  98
  99