OneEye Changeset - d07ae4bfa145

Changeset - d07ae4bfa145

Parent rev.

Child rev.

[Not reviewed]

default

0 3 0

Laman - 6 years ago 2019-03-06 18:03:44

transforming points and lines with a matrix

3 files changed with 40 insertions and 4 deletions:

exp/geometry.py

exp/tests/test_geometry.py

src/analyzer/epoint.py

0 comments (0 inline, 0 general)

exp/geometry.py

➞

Show inline comments

@@ @@ -25,12 +25,24 @@ class Line: @@
 	def toNormal(self):
 		# https://en.wikipedia.org/wiki/Line_(mathematics)#In_normal_form
 		"""ax + by + c = 0"""
 		return (self._cos, self._sin, -self._d)
 	def toPoints(self):
 		(a,b,c)=self.toNormal()
 		assert a!=0 or b!=0
 		if a==0:
 			y=-c/b
 			return (EPoint(0,y),EPoint(10,y))
 		elif b==0:
 			x=-c/a
 			return (EPoint(x,0),EPoint(x,10))
 		else:
 			return (EPoint(0,-c/b),EPoint(-c/a,0))
 	def intersect(self,line):
 		if self._alpha==line._alpha: return None
 		(a,b,c)=self.toNormal()
 		(d,e,f)=line.toNormal()
 		x=(b*f-c*e)/(a*e-b*d)
 		y=(c*d-a*f)/(a*e-b*d)
@@ @@ -48,12 +60,16 @@ class Line: @@
 		else:
 			point=EPoint(0,-c/b)
 		(x_,y_)=point-newBasis
 		c_=-a*x_-b*y_
 		return Line.fromNormal(a,b,c_)
 	def transform(self,matrix):
 		transformed=(p.transform(matrix) for p in self.toPoints())
 		return Line.fromPoints(*transformed)
 	@property
 	def alpha(self): return self._alpha
 	@property
 	def d(self): return self._d

exp/tests/test_geometry.py

➞

Show inline comments

 import math
 import random
 from unittest import TestCase
 import numpy as np
 from geometry import Line,EPoint
 random.seed(361)
 class TestLine(TestCase):
@@ @@ -86,6 +88,18 @@ class TestLine(TestCase): @@
 		self.assertAlmostEqual(p_._d,diag/2)
 		q=Line(math.pi*3/4,-diag/2)
 		q_=q.shiftBasis(newBasis)
 		self.assertAlmostEqual(q_._alpha,math.pi*7/4)
 		self.assertAlmostEqual(q_._d,3/2*diag)
 	def testTransform(self):
 		rot90=np.array([[0,-1,0],[1,0,0],[0,0,1]])
 		p=Line(math.pi/4,10)
 		p_=p.transform(rot90)
 		self.assertAlmostEqual(p_.alpha,math.pi*3/4)
 		self.assertAlmostEqual(p_.d,p.d)
 		shiftXY10=np.array([[1,0,10],[0,1,10],[0,0,1]])
 		p_=p.transform(shiftXY10)
 		self.assertAlmostEqual(p_.alpha,p.alpha)
 		self.assertAlmostEqual(p_.d,10+10*math.sqrt(2))

src/analyzer/epoint.py

➞

Show inline comments

 import math
 import numpy as np
 def homogenize(v):
 	for k in v:
+	for k in reversed(v):
 		if k!=0: return v/k
 	return v
 ## Euclidean 2D plane point: (x,y).
 class EPoint:
@@ @@ -18,32 +20,36 @@ class EPoint: @@
 	@property
 	def y(self): return self._y
 	@staticmethod
 	def fromProjective(point):
 		if point.item(0)==0: return None
 		return EPoint(point.item(1)/point.item(0),point.item(2)/point.item(0))
 		if point.item(2)==0: return None
 		return EPoint(point.item(0)/point.item(2),point.item(1)/point.item(2))
 	@staticmethod
 	def fromPolar(point,center):
 		(alpha,length)=point
 		x=math.cos(alpha)
 		y=math.sin(alpha)
 		return length*EPoint(x,y)+center
 	def toProjective(self):
-		return (1,self._x,self._y)
+		return (self._x,self._y,1)
 	def toPolar(self,center):
 		v=self-center
 		alpha=math.atan2(v.y,v.x)
 		if alpha<0: alpha+=2*math.pi
 		k=self.dist(center)
 		return (alpha,k)
 	def transform(self,matrix):
 		transformed=np.matmul(matrix,np.array(self.toProjective()).transpose())
 		return EPoint.fromProjective(transformed)
 	def dist(self,a):
 		return math.sqrt((self._x-a._x)**2+(self._y-a._y)**2)
 	def __add__(self,a):
 		return EPoint(self._x+a._x,self._y+a._y)

0 comments (0 inline, 0 general)