From 16dacbd5b2178bdd93dbae0e58bcf80d6fec548d Mon Sep 17 00:00:00 2001 From: Luca Heltai Date: Sat, 17 Jan 2015 02:41:30 +0100 Subject: [PATCH] Fixed wolfgang comments. --- examples/step-1/step-1.cc | 33 ++++++++++++++++++--------------- examples/step-10/step-10.cc | 7 ++++--- 2 files changed, 22 insertions(+), 18 deletions(-) diff --git a/examples/step-1/step-1.cc b/examples/step-1/step-1.cc index 93c7803d9a..9c271a941e 100644 --- a/examples/step-1/step-1.cc +++ b/examples/step-1/step-1.cc @@ -101,28 +101,31 @@ void second_grid () center, inner_radius, outer_radius, 10); // By default, the triangulation assumes that all boundaries are - // straigth lines, and all cells are bi-linear quads, and that they - // are defined by the cells of the coarse grid (which we just - // created). It uses this information when cells are refined and new - // points need to be introduced; if the domain is assumed to be - // flat, then new points will simply be in the middle of the - // surrounding ones. - // + // straight lines, and all cells are bi-linear quads or tri-linear + // hexes, and that they are defined by the cells of the coarse grid + // (which we just created). Unless we do something special, when new + // points need to be introduced; the domain is assumed to be + // delineated by the straight lines of the coarse mesh, and new + // points will simply be in the middle of the surrounding ones. // Here, however, we know that the domain is curved, and we would // like to have the Triangulation place new points according to the // underlying geometry. Fortunately, some good soul implemented an // object which describes a spherical domain, of which the ring is a // section; it only needs the center of the ring and automatically // figures out how to instruct the Triangulation where to place the - // new points. We first set the "manifold indicator" of all cells - // and faces of the Triangulation to the value zero, and then - // associate the curved Manifold object with those parts of the - // Triangulation that have the "manifold indicator" zero. By - // default, all cells and faces of the Triangulation have their - // manifold_id set to numbers::invalid_manifold_id, which is the - // default if you want a flat manifold, but you can change this + // new points. The way this works in deal.II is that you tag parts + // of the triangulation you want to be curved with a number that is + // usually referred to as "boundary indicator" and then tell the + // triangulation to use a particular "manifold object" for all + // places with this manifold indicator. How exactly this works is + // not important at this point (you can read up on it in step-53 and + // @ref manifold). Here, for simplicity, we will choose the manifold + // id to be zero. By default, all cells and faces of the + // Triangulation have their manifold_id set to + // numbers::invalid_manifold_id, which is the default if you want a + // manifold that produces straight edges, but you can change this // number for individual cells and faces. In that case, the curved - // manifold thus associated with number zero will not apply on those + // manifold thus associated with number zero will not apply to those // parts with a non-zero manifold indicator, but other manifold // description objects can be associated with those non-zero // indicators. If no manifold description is associated with a diff --git a/examples/step-10/step-10.cc b/examples/step-10/step-10.cc index 94c3b673e5..dabb362707 100644 --- a/examples/step-10/step-10.cc +++ b/examples/step-10/step-10.cc @@ -75,9 +75,10 @@ namespace Step10 std::cout << "Output of grids into gnuplot files:" << std::endl << "===================================" << std::endl; - // So first generate a coarse triangulation of the circle and associate a - // suitable boundary description to it. Note that the default values of - // the SphericalManifold constructor is a center at the origin. + // So first generate a coarse triangulation of the circle and + // associate a suitable boundary description to it. Note that the + // default value of the argument to the SphericalManifold + // constructor is a center at the origin. Triangulation triangulation; GridGenerator::hyper_ball (triangulation); static const SphericalManifold boundary; -- 2.39.5