From c4fd2855e6ff9252003d7b2607570ce6884938c4 Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Fri, 9 Oct 2015 09:20:15 +0700 Subject: [PATCH 1/5] Add support for general quadric surfaces --- docs/source/methods/geometry.rst | 4 + docs/source/usersguide/input.rst | 8 +- docs/source/usersguide/output/summary.rst | 3 +- src/input_xml.F90 | 14 +++ src/summary.F90 | 5 ++ src/surface_header.F90 | 102 +++++++++++++++++++++- 6 files changed, 131 insertions(+), 5 deletions(-) diff --git a/docs/source/methods/geometry.rst b/docs/source/methods/geometry.rst index 9eece1e919..6592909298 100644 --- a/docs/source/methods/geometry.rst +++ b/docs/source/methods/geometry.rst @@ -117,6 +117,10 @@ to fully define the surface. | Cone parallel to the | z-cone | :math:`(x-x_0)^2 + (y-y_0)^2 | :math:`x_0 \; y_0 \; | | :math:`z`-axis | | = R^2(z-z_0)^2` | z_0 \; R^2` | +----------------------+------------+------------------------------+-------------------------+ + | General quadric | quadric | :math:`Ax^2 + By^2 + Cz^2 + | :math:`A \; B \; C \; D | + | surface | | Dxy + Eyz + Fxz + Gx + Hy + | \; E \; F \; G \; H \; | + | | | Jz + K` | J \; K` | + +----------------------+------------+------------------------------+-------------------------+ .. _universes: diff --git a/docs/source/usersguide/input.rst b/docs/source/usersguide/input.rst index 44db252079..87b613a453 100644 --- a/docs/source/usersguide/input.rst +++ b/docs/source/usersguide/input.rst @@ -787,7 +787,7 @@ Each ```` element can have the following attributes or sub-elements: :type: The type of the surfaces. This can be "x-plane", "y-plane", "z-plane", "plane", "x-cylinder", "y-cylinder", "z-cylinder", "sphere", "x-cone", - "y-cone", or "z-cone". + "y-cone", "z-cone", or "quadric". *Default*: None @@ -855,6 +855,12 @@ The following quadratic surfaces can be modeled: R^2 (z - z_0)^2`. The coefficients specified are ":math:`x_0 \: y_0 \: z_0 \: R^2`". + :quadric: + A general quadric surface of the form :math:`Ax^2 + By^2 + Cz^2 + Dxy + + Eyz + Fxz + Gx + Hy + Jz + K = 0` The coefficients specified are ":math:`A + \: B \: C \: D \: E \: F \: G \: H \: J \: K`". + + ```` Element ------------------ diff --git a/docs/source/usersguide/output/summary.rst b/docs/source/usersguide/output/summary.rst index d37b2172fa..f87f60c4a0 100644 --- a/docs/source/usersguide/output/summary.rst +++ b/docs/source/usersguide/output/summary.rst @@ -132,7 +132,8 @@ The current revision of the summary file format is 1. **/geometry/surfaces/surface /type** (*char[]*) Type of the surface. Can be 'x-plane', 'y-plane', 'z-plane', 'plane', - 'x-cylinder', 'y-cylinder', 'sphere', 'x-cone', 'y-cone', or 'z-cone'. + 'x-cylinder', 'y-cylinder', 'sphere', 'x-cone', 'y-cone', 'z-cone', or + 'quadric'. **/geometry/surfaces/surface /coefficients** (*double[]*) diff --git a/src/input_xml.F90 b/src/input_xml.F90 index 6d15f0d204..40e0583daf 100644 --- a/src/input_xml.F90 +++ b/src/input_xml.F90 @@ -1294,6 +1294,9 @@ contains case ('z-cone') coeffs_reqd = 4 allocate(SurfaceZCone :: surfaces(i)%obj) + case ('quadric') + coeffs_reqd = 10 + allocate(SurfaceQuadric :: surfaces(i)%obj) case default call fatal_error("Invalid surface type: " // trim(word)) end select @@ -1378,6 +1381,17 @@ contains s%y0 = coeffs(2) s%z0 = coeffs(3) s%r2 = coeffs(4) + type is (SurfaceQuadric) + s%A = coeffs(1) + s%B = coeffs(2) + s%C = coeffs(3) + s%D = coeffs(4) + s%E = coeffs(5) + s%F = coeffs(6) + s%G = coeffs(7) + s%H = coeffs(8) + s%J = coeffs(9) + s%K = coeffs(10) end select ! No longer need coefficients diff --git a/src/summary.F90 b/src/summary.F90 index 1bf57cc93f..d8ac1e3fa8 100644 --- a/src/summary.F90 +++ b/src/summary.F90 @@ -276,6 +276,11 @@ contains allocate(coeffs(4)) coeffs(:) = [s%x0, s%y0, s%z0, s%r2] + type is (SurfaceQuadric) + call write_dataset(surface_group, "type", "quadric") + allocate(coeffs(10)) + coeffs(:) = [s%A, s%B, s%C, s%D, s%E, s%F, s%G, s%H, s%J, s%K] + end select call write_dataset(surface_group, "coefficients", coeffs) deallocate(coeffs) diff --git a/src/surface_header.F90 b/src/surface_header.F90 index 6fc1bbc237..a927ce4d40 100644 --- a/src/surface_header.F90 +++ b/src/surface_header.F90 @@ -1,6 +1,6 @@ module surface_header - use constants, only: ONE, TWO, ZERO, INFINITY, FP_COINCIDENT + use constants, only: ONE, TWO, ZERO, HALF, INFINITY, FP_COINCIDENT implicit none @@ -183,6 +183,15 @@ module surface_header procedure :: normal => z_cone_normal end type SurfaceZCone + type, extends(Surface) :: SurfaceQuadric + ! Ax^2 + By^2 + Cz^2 + Dxy + Eyz + Fxz + Gx + Hy + Jz + K = 0 + real(8) :: A, B, C, D, E, F, G, H, J, K + contains + procedure :: evaluate => quadric_evaluate + procedure :: distance => quadric_distance + procedure :: normal => quadric_normal + end type SurfaceQuadric + contains !=============================================================================== @@ -640,7 +649,7 @@ contains end function z_cylinder_normal !=============================================================================== -! SphereImplementation +! SurfaceSphere Implementation !=============================================================================== pure function sphere_evaluate(this, xyz) result(f) @@ -874,7 +883,7 @@ contains end function y_cone_normal !=============================================================================== -! SurfaceZConeImplementation +! SurfaceZCone Implementation !=============================================================================== pure function z_cone_evaluate(this, xyz) result(f) @@ -953,4 +962,91 @@ contains uvw(3) = -TWO*this%r2*(xyz(3) - this%z0) end function z_cone_normal +!=============================================================================== +! SurfaceQuadric Implementation +!=============================================================================== + + pure function quadric_evaluate(this, xyz) result(f) + class(SurfaceQuadric), intent(in) :: this + real(8), intent(in) :: xyz(3) + real(8) :: f + + associate (x => xyz(1), y => xyz(2), z => xyz(3)) + f = x*(this%A*x + this%D*y + this%G) + & + y*(this%B*y + this%E*z + this%H) + & + z*(this%C*z + this%F*x + this%J) + this%K + end associate + end function quadric_evaluate + + pure function quadric_distance(this, xyz, uvw, coincident) result(d) + class(SurfaceQuadric), intent(in) :: this + real(8), intent(in) :: xyz(3) + real(8), intent(in) :: uvw(3) + logical, intent(in) :: coincident + real(8) :: d + + real(8) :: a, k, c + real(8) :: quad, b + + associate (x => xyz(1), y => xyz(2), z => xyz(3), & + u => uvw(1), v => uvw(2), w => uvw(3)) + + a = this%A*u*u + this%B*v*v + this%C*w*w + this%D*u*v + this%E*v*w + & + this%F*u*w + k = (this%A*u*x + this%B*v*y + this%C*w*z + HALF*(this%D*(u*y + v*x) + & + this%E*(v*z + w*y) + this%F*(w*x + u*z) + this%G*u + this%H*v + & + this%J*w)) + c = this%A*x*x + this%B*y*y + this%C*z*z + this%D*x*y + this%E*y*z + & + this%F*y*z + this%G*x + this%H*y + this%J*z + K + quad = k*k - a*c + + if (quad < ZERO) then + ! no intersection with cone + + d = INFINITY + + elseif (coincident .or. abs(c) < FP_COINCIDENT) then + ! particle is on the cone, thus one distance is positive/negative and the + ! other is zero. The sign of k determines which distance is zero and which + ! is not. + + if (k >= ZERO) then + d = (-k - sqrt(quad))/a + else + d = (-k + sqrt(quad))/a + end if + + else + ! calculate both solutions to the quadratic + quad = sqrt(quad) + d = (-k - quad)/a + b = (-k + quad)/a + + ! determine the smallest positive solution + if (d < ZERO) then + if (b > ZERO) then + d = b + end if + else + if (b > ZERO) d = min(d, b) + end if + end if + + ! If the distance was negative, set boundary distance to infinity + if (d <= ZERO) d = INFINITY + end associate + end function quadric_distance + + pure function quadric_normal(this, xyz) result(uvw) + class(SurfaceQuadric), intent(in) :: this + real(8), intent(in) :: xyz(3) + real(8) :: uvw(3) + + associate (x => xyz(1), y => xyz(2), z => xyz(3)) + uvw(1) = TWO*this%A*x + this%D*y + this%F*z + this%G + uvw(2) = TWO*this%B*y + this%D*x + this%E*z + this%H + uvw(3) = TWO*this%C*z + this%E*y + this%F*x + this%J + end associate + end function quadric_normal + end module surface_header From 80b0a1ad251090159a4f8465511ed01ddfca8ec7 Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Fri, 9 Oct 2015 09:36:00 +0700 Subject: [PATCH 2/5] Add support in Python API for quadric surfaces --- openmc/summary.py | 5 ++ openmc/surface.py | 146 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 151 insertions(+) diff --git a/openmc/summary.py b/openmc/summary.py index 75f2a0f2a2..2c704557c8 100644 --- a/openmc/summary.py +++ b/openmc/summary.py @@ -179,6 +179,11 @@ class Summary(object): if surf_type == 'z-cone': surface = openmc.ZCone(surface_id, bc, x0, y0, z0, R2, name) + elif surf_type == 'quadric': + a, b, c, d, e, f, g, h, j, k = coeffs + surface = openmc.Quadric(surface_id, bc, a, b, c, d, e, f, + g, h, j, k, name) + # Add Surface to global dictionary of all Surfaces self.surfaces[index] = surface diff --git a/openmc/surface.py b/openmc/surface.py index afa426fa3b..92f047b66d 100644 --- a/openmc/surface.py +++ b/openmc/surface.py @@ -949,6 +949,152 @@ class ZCone(Cone): self._type = 'z-cone' +class Quadric(Surface): + """A sphere of the form :math:`Ax^2 + By^2 + Cz^2 + Dxy + Eyz + Fxz + Gx + Hy + + Jz + K`. + + Parameters + ---------- + surface_id : int + Unique identifier for the surface. If not specified, an identifier will + automatically be assigned. + boundary_type : {'transmission, 'vacuum', 'reflective', 'periodic'} + Boundary condition that defines the behavior for particles hitting the + surface. Defaults to transmissive boundary condition where particles + freely pass through the surface. + a, b, c, d, e, f, g, h, j, k : float + coefficients for the surface + name : str + Name of the sphere. If not specified, the name will be the empty string. + + Attributes + ---------- + a, b, c, d, e, f, g, h, j, k : float + coefficients for the surface + + """ + + def __init__(self, surface_id=None, boundary_type='transmission', + a=None, b=None, c=None, d=None, e=None, f=None, g=None, + h=None, j=None, k=None, name=''): + # Initialize Quadric class attributes + super(Quadric, self).__init__(surface_id, boundary_type, name=name) + + self._type = 'quadric' + self._coeff_keys = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k'] + + if a is not None: + self.a = a + if b is not None: + self.b = b + if c is not None: + self.c = c + if d is not None: + self.d = d + if e is not None: + self.e = e + if f is not None: + self.f = f + if g is not None: + self.g = g + if h is not None: + self.h = h + if j is not None: + self.j = j + if k is not None: + self.k = k + + @property + def a(self): + return self.coeffs['a'] + + @property + def b(self): + return self.coeffs['b'] + + @property + def c(self): + return self.coeffs['c'] + + @property + def d(self): + return self.coeffs['d'] + + @property + def e(self): + return self.coeffs['e'] + + @property + def f(self): + return self.coeffs['f'] + + @property + def g(self): + return self.coeffs['g'] + + @property + def h(self): + return self.coeffs['h'] + + @property + def j(self): + return self.coeffs['j'] + + @property + def k(self): + return self.coeffs['k'] + + @a.setter + def a(self, a): + check_type('a coefficient', a, Real) + self._coeffs['a'] = a + + @b.setter + def b(self, b): + check_type('b coefficient', b, Real) + self._coeffs['b'] = b + + @c.setter + def c(self, c): + check_type('c coefficient', c, Real) + self._coeffs['c'] = c + + @d.setter + def d(self, d): + check_type('d coefficient', d, Real) + self._coeffs['d'] = d + + @e.setter + def e(self, e): + check_type('e coefficient', e, Real) + self._coeffs['e'] = e + + @f.setter + def f(self, f): + check_type('f coefficient', f, Real) + self._coeffs['f'] = f + + @g.setter + def g(self, g): + check_type('g coefficient', g, Real) + self._coeffs['g'] = g + + @h.setter + def h(self, h): + check_type('h coefficient', h, Real) + self._coeffs['h'] = h + + @j.setter + def j(self, j): + check_type('j coefficient', j, Real) + self._coeffs['j'] = j + + @k.setter + def k(self, k): + check_type('k coefficient', k, Real) + self._coeffs['k'] = k + + class Halfspace(Region): """A positive or negative half-space region. From 8fdc5fbba1eea407f9f919980c6456e6cf768591 Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Fri, 9 Oct 2015 15:05:55 +0700 Subject: [PATCH 3/5] Add test for quadric surface and fix bug in distance calculation. Also remove reflective cone, cylinder, and sphere tests since they are covered in the new test here. --- src/geometry.F90 | 2 +- src/surface_header.F90 | 2 +- tests/test_quadric_surfaces/geometry.xml | 14 ++++++++++++++ .../materials.xml | 3 ++- tests/test_quadric_surfaces/results_true.dat | 2 ++ .../settings.xml | 2 +- .../test_quadric_surfaces.py} | 0 tests/test_reflective_cone/geometry.xml | 7 ------- tests/test_reflective_cone/materials.xml | 9 --------- tests/test_reflective_cone/results_true.dat | 2 -- tests/test_reflective_cylinder/geometry.xml | 8 -------- tests/test_reflective_cylinder/materials.xml | 9 --------- tests/test_reflective_cylinder/results_true.dat | 2 -- tests/test_reflective_cylinder/settings.xml | 16 ---------------- .../test_reflective_cylinder.py | 11 ----------- tests/test_reflective_sphere/geometry.xml | 8 -------- tests/test_reflective_sphere/results_true.dat | 2 -- tests/test_reflective_sphere/settings.xml | 16 ---------------- .../test_reflective_sphere.py | 11 ----------- 19 files changed, 21 insertions(+), 105 deletions(-) create mode 100644 tests/test_quadric_surfaces/geometry.xml rename tests/{test_reflective_sphere => test_quadric_surfaces}/materials.xml (56%) create mode 100644 tests/test_quadric_surfaces/results_true.dat rename tests/{test_reflective_cone => test_quadric_surfaces}/settings.xml (79%) rename tests/{test_reflective_cone/test_reflective_cone.py => test_quadric_surfaces/test_quadric_surfaces.py} (100%) mode change 100644 => 100755 delete mode 100644 tests/test_reflective_cone/geometry.xml delete mode 100644 tests/test_reflective_cone/materials.xml delete mode 100644 tests/test_reflective_cone/results_true.dat delete mode 100644 tests/test_reflective_cylinder/geometry.xml delete mode 100644 tests/test_reflective_cylinder/materials.xml delete mode 100644 tests/test_reflective_cylinder/results_true.dat delete mode 100644 tests/test_reflective_cylinder/settings.xml delete mode 100644 tests/test_reflective_cylinder/test_reflective_cylinder.py delete mode 100644 tests/test_reflective_sphere/geometry.xml delete mode 100644 tests/test_reflective_sphere/results_true.dat delete mode 100644 tests/test_reflective_sphere/settings.xml delete mode 100644 tests/test_reflective_sphere/test_reflective_sphere.py diff --git a/src/geometry.F90 b/src/geometry.F90 index e1e1b1f44e..e922479b1d 100644 --- a/src/geometry.F90 +++ b/src/geometry.F90 @@ -430,7 +430,7 @@ contains call find_cell(p, found) if (.not. found) then call handle_lost_particle(p, "Couldn't find particle after reflecting& - & from surface.") + & from surface " // trim(to_str(surf%id)) // ".") return end if diff --git a/src/surface_header.F90 b/src/surface_header.F90 index a927ce4d40..257cdbc1a1 100644 --- a/src/surface_header.F90 +++ b/src/surface_header.F90 @@ -997,7 +997,7 @@ contains this%E*(v*z + w*y) + this%F*(w*x + u*z) + this%G*u + this%H*v + & this%J*w)) c = this%A*x*x + this%B*y*y + this%C*z*z + this%D*x*y + this%E*y*z + & - this%F*y*z + this%G*x + this%H*y + this%J*z + K + this%F*x*z + this%G*x + this%H*y + this%J*z + this%K quad = k*k - a*c if (quad < ZERO) then diff --git a/tests/test_quadric_surfaces/geometry.xml b/tests/test_quadric_surfaces/geometry.xml new file mode 100644 index 0000000000..98d647a4f6 --- /dev/null +++ b/tests/test_quadric_surfaces/geometry.xml @@ -0,0 +1,14 @@ + + + + + + + + + + + + + + diff --git a/tests/test_reflective_sphere/materials.xml b/tests/test_quadric_surfaces/materials.xml similarity index 56% rename from tests/test_reflective_sphere/materials.xml rename to tests/test_quadric_surfaces/materials.xml index 315c0fa848..0150332b3c 100644 --- a/tests/test_reflective_sphere/materials.xml +++ b/tests/test_quadric_surfaces/materials.xml @@ -3,7 +3,8 @@ - + + diff --git a/tests/test_quadric_surfaces/results_true.dat b/tests/test_quadric_surfaces/results_true.dat new file mode 100644 index 0000000000..b2e02fdbb7 --- /dev/null +++ b/tests/test_quadric_surfaces/results_true.dat @@ -0,0 +1,2 @@ +k-combined: +9.706301E-01 4.351374E-02 diff --git a/tests/test_reflective_cone/settings.xml b/tests/test_quadric_surfaces/settings.xml similarity index 79% rename from tests/test_reflective_cone/settings.xml rename to tests/test_quadric_surfaces/settings.xml index af56f56368..9f0e8ed05f 100644 --- a/tests/test_reflective_cone/settings.xml +++ b/tests/test_quadric_surfaces/settings.xml @@ -8,7 +8,7 @@ - + diff --git a/tests/test_reflective_cone/test_reflective_cone.py b/tests/test_quadric_surfaces/test_quadric_surfaces.py old mode 100644 new mode 100755 similarity index 100% rename from tests/test_reflective_cone/test_reflective_cone.py rename to tests/test_quadric_surfaces/test_quadric_surfaces.py diff --git a/tests/test_reflective_cone/geometry.xml b/tests/test_reflective_cone/geometry.xml deleted file mode 100644 index f5499fbb61..0000000000 --- a/tests/test_reflective_cone/geometry.xml +++ /dev/null @@ -1,7 +0,0 @@ - - - - - - - diff --git a/tests/test_reflective_cone/materials.xml b/tests/test_reflective_cone/materials.xml deleted file mode 100644 index 315c0fa848..0000000000 --- a/tests/test_reflective_cone/materials.xml +++ /dev/null @@ -1,9 +0,0 @@ - - - - - - - - - diff --git a/tests/test_reflective_cone/results_true.dat b/tests/test_reflective_cone/results_true.dat deleted file mode 100644 index c8b833bff4..0000000000 --- a/tests/test_reflective_cone/results_true.dat +++ /dev/null @@ -1,2 +0,0 @@ -k-combined: -2.269987E+00 4.469683E-03 diff --git a/tests/test_reflective_cylinder/geometry.xml b/tests/test_reflective_cylinder/geometry.xml deleted file mode 100644 index e6aed65daf..0000000000 --- a/tests/test_reflective_cylinder/geometry.xml +++ /dev/null @@ -1,8 +0,0 @@ - - - - - - - - diff --git a/tests/test_reflective_cylinder/materials.xml b/tests/test_reflective_cylinder/materials.xml deleted file mode 100644 index 315c0fa848..0000000000 --- a/tests/test_reflective_cylinder/materials.xml +++ /dev/null @@ -1,9 +0,0 @@ - - - - - - - - - diff --git a/tests/test_reflective_cylinder/results_true.dat b/tests/test_reflective_cylinder/results_true.dat deleted file mode 100644 index 0a11f3ef31..0000000000 --- a/tests/test_reflective_cylinder/results_true.dat +++ /dev/null @@ -1,2 +0,0 @@ -k-combined: -2.272436E+00 7.831006E-04 diff --git a/tests/test_reflective_cylinder/settings.xml b/tests/test_reflective_cylinder/settings.xml deleted file mode 100644 index a6fd5da19e..0000000000 --- a/tests/test_reflective_cylinder/settings.xml +++ /dev/null @@ -1,16 +0,0 @@ - - - - - 10 - 5 - 1000 - - - - - -4 -4 -4 4 4 4 - - - - diff --git a/tests/test_reflective_cylinder/test_reflective_cylinder.py b/tests/test_reflective_cylinder/test_reflective_cylinder.py deleted file mode 100644 index 2a595f3e66..0000000000 --- a/tests/test_reflective_cylinder/test_reflective_cylinder.py +++ /dev/null @@ -1,11 +0,0 @@ -#!/usr/bin/env python - -import os -import sys -sys.path.insert(0, os.pardir) -from testing_harness import TestHarness - - -if __name__ == '__main__': - harness = TestHarness('statepoint.10.*') - harness.main() diff --git a/tests/test_reflective_sphere/geometry.xml b/tests/test_reflective_sphere/geometry.xml deleted file mode 100644 index 0dc98eba69..0000000000 --- a/tests/test_reflective_sphere/geometry.xml +++ /dev/null @@ -1,8 +0,0 @@ - - - - - - - - diff --git a/tests/test_reflective_sphere/results_true.dat b/tests/test_reflective_sphere/results_true.dat deleted file mode 100644 index 91dd20fba8..0000000000 --- a/tests/test_reflective_sphere/results_true.dat +++ /dev/null @@ -1,2 +0,0 @@ -k-combined: -2.271012E+00 3.466351E-03 diff --git a/tests/test_reflective_sphere/settings.xml b/tests/test_reflective_sphere/settings.xml deleted file mode 100644 index a6fd5da19e..0000000000 --- a/tests/test_reflective_sphere/settings.xml +++ /dev/null @@ -1,16 +0,0 @@ - - - - - 10 - 5 - 1000 - - - - - -4 -4 -4 4 4 4 - - - - diff --git a/tests/test_reflective_sphere/test_reflective_sphere.py b/tests/test_reflective_sphere/test_reflective_sphere.py deleted file mode 100644 index 2a595f3e66..0000000000 --- a/tests/test_reflective_sphere/test_reflective_sphere.py +++ /dev/null @@ -1,11 +0,0 @@ -#!/usr/bin/env python - -import os -import sys -sys.path.insert(0, os.pardir) -from testing_harness import TestHarness - - -if __name__ == '__main__': - harness = TestHarness('statepoint.10.*') - harness.main() From d61424218f9580053e89a7301e0acebb1b8537f8 Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Fri, 9 Oct 2015 15:22:50 +0700 Subject: [PATCH 4/5] Clarify geometry methods documentation --- docs/source/methods/geometry.rst | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/docs/source/methods/geometry.rst b/docs/source/methods/geometry.rst index 6592909298..c1be68f72e 100644 --- a/docs/source/methods/geometry.rst +++ b/docs/source/methods/geometry.rst @@ -10,7 +10,7 @@ Constructive Solid Geometry OpenMC uses a technique known as `constructive solid geometry`_ (CSG) to build arbitrarily complex three-dimensional models in Euclidean space. In a CSG model, -every unique object is described as the union, intersection, or difference of +every unique object is described as the union and/or intersection of *half-spaces* created by bounding `surfaces`_. Every surface divides all of space into exactly two half-spaces. We can mathematically define a surface as a collection of points that satisfy an equation of the form :math:`f(x,y,z) = 0` @@ -54,13 +54,12 @@ dividing space into two half-spaces. Example of an ellipse and its associated half-spaces. References to half-spaces created by surfaces are used to define regions of -space of uniform composition, known as *cells*. While some codes allow regions -to be defined by intersections, unions, and differences or half-spaces, OpenMC -is currently limited to cells defined only as intersections of -half-spaces. Thus, the specification of the cell must include a list of -half-space references whose intersection defines the region. The region is then -assigned a material defined elsewhere. Figure :num:`fig-union` shows an -example of a cell defined as the intersection of an ellipse and two planes. +space of uniform composition, which are then assigned to *cells*. OpenMC allows +regions to be defined using union, intersection, and complement operators. As in +MCNP_, the intersection operator is implicit as doesn't need to be written in a +region specification. A defined region is then associated with a material +composition in a cell. Figure :num:`fig-union` shows an example of a cell region +defined as the intersection of an ellipse and two planes. .. _fig-union: From 7adde6fcb3c7744e8bd6104c09ea04bfd5316efd Mon Sep 17 00:00:00 2001 From: Paul Romano Date: Fri, 9 Oct 2015 21:35:55 +0700 Subject: [PATCH 5/5] Fix comments in quadric_distance --- src/surface_header.F90 | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/surface_header.F90 b/src/surface_header.F90 index 257cdbc1a1..8b4ed00919 100644 --- a/src/surface_header.F90 +++ b/src/surface_header.F90 @@ -1001,14 +1001,14 @@ contains quad = k*k - a*c if (quad < ZERO) then - ! no intersection with cone + ! no intersection with surface d = INFINITY elseif (coincident .or. abs(c) < FP_COINCIDENT) then - ! particle is on the cone, thus one distance is positive/negative and the - ! other is zero. The sign of k determines which distance is zero and which - ! is not. + ! particle is on the surface, thus one distance is positive/negative and + ! the other is zero. The sign of k determines which distance is zero and + ! which is not. if (k >= ZERO) then d = (-k - sqrt(quad))/a