def calc_epm_zones(pts):
if len(pts) != 8:
print >> sys.stderr, 'argument must be list of length 8; length is %s. argument pts:\n%s' % (len(pts),pts)
raise ValueError
else:
outerpts = []
m1,b1 = vidtools.line_fx_from_pts(pts[0],pts[1])
m2,b2 = vidtools.line_fx_from_pts(pts[7],pts[6])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
outerpts.append((x,y))
m2,b2 = vidtools.line_fx_from_pts(pts[2],pts[3])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
outerpts.append((x,y))
m1,b1 = vidtools.line_fx_from_pts(pts[4],pts[5])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
outerpts.append((x,y))
m2,b2 = vidtools.line_fx_from_pts(pts[7],pts[6])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
outerpts.append((x,y))
centerpts = []
m1,b1 = vidtools.line_fx_from_pts(pts[0],pts[5])
m2,b2 = vidtools.line_fx_from_pts(pts[7],pts[2])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
centerpts.append((x,y))
m1,b1 = vidtools.line_fx_from_pts(pts[1],pts[4])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
centerpts.append((x,y))
centerpts
m2,b2 = vidtools.line_fx_from_pts(pts[6],pts[3])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
centerpts.append((x,y))
m1,b1 = vidtools.line_fx_from_pts(pts[0],pts[5])
x = (b2-b1)/(m1-m2)
y = m2*x+b2
centerpts.append((x,y))
zones = {}
zones['F1'] = [outerpts[0],pts[0],centerpts[0],pts[7]]
zones['F2'] = [pts[1],outerpts[1],pts[2],centerpts[1]]
zones['F3'] = [centerpts[2],pts[3],outerpts[2],pts[4]]
zones['F4'] = [pts[6],centerpts[3],pts[5],outerpts[3]]
zones['OT'] = [pts[0],pts[1],centerpts[1],centerpts[0]]
zones['OB'] = [centerpts[3],centerpts[2],pts[4],pts[5]]
zones['CR'] = [centerpts[1],pts[2],pts[3],centerpts[2]]
zones['CL'] = [pts[7],centerpts[0],centerpts[3],pts[6]]
zones['M'] = centerpts
return zones
def nearest_point_on_line(lpt1,lpt2,qpt): h = vidtools.hypotenuse(lpt1,lpt2) xdiff = lpt2[0] - lpt1[0] m,b = vidtools.line_fx_from_pts(lpt1,lpt2) xstep = xdiff/h lpoly = [(x,(m*x+b)) for x in numpy.arange(lpt1[0],lpt2[0],xstep)] return vidtools.perigee(lpoly,[qpt])
def calc_chord_stats(tun,cm_factor=1):
h = vidtools.hypotenuse(tun[0],tun[-1])
xdiff = tun[-1][0] - tun[0][0]
m,b = vidtools.line_fx_from_pts(tun[0],tun[-1])
xstep = xdiff/h
lpoly = [(x,(m*x+b)) for x in numpy.arange(tun[0][0],tun[-1][0],xstep)]
on_chord_pt,on_curve_pt = max([(vidtools.hypotenuse(*vidtools.perigee(lpoly,[p])),vidtools.perigee(lpoly,[p])) for p in tun])[1]
chord_len = vidtools.hypotenuse(tun[0],tun[-1])/cm_factor
chord_pt = vidtools.hypotenuse(tun[0],on_chord_pt)/cm_factor
chord_dp = vidtools.hypotenuse(on_chord_pt,on_curve_pt)/cm_factor
return chord_len, chord_pt, chord_dp