design/boxalign.py

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