From: Timo Heister <timo.heister@gmail.com>
Date: Wed, 20 Oct 2021 22:00:19 +0000 (-0400)
Subject: fix step-49 geo file
X-Git-Tag: v9.4.0-rc1~900^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F12855%2Fhead;p=dealii.git

fix step-49 geo file

- do not use opencascade circle command
- reassign a few of the ids
- update documentation.

fixes #12826
---

diff --git a/examples/step-49/doc/intro.dox b/examples/step-49/doc/intro.dox
index e82c9f51ce..69aa56f8c2 100644
--- a/examples/step-49/doc/intro.dox
+++ b/examples/step-49/doc/intro.dox
@@ -205,9 +205,10 @@ Point(104) = {-2.8, -1.54, 0, 1.0}; // left point
 Then we use the <code>Circle arc</code> entity, which is found in the same category as
 <code>%Point</code> and <code>Lines</code>.  The file reads "Circle"
 but the difference to note is that this function uses three points to
-make an arc of a circle, namely the starting point, center, and ending point.
-Splitting the circle into four arcs like this allows for more freedom when declaring the
-boundary IDs. Constructing a circle from four arcs then looks as follows
+make an arc of a circle, namely the starting point, center, and ending point. The
+angle of an arc is required to be less than 180 degrees. We therefore split the circle
+into four arcs, which also allows us to set different boundary IDs.
+This then looks as follows
 where point 31 is the common center for all arcs:
 
 @code
@@ -217,13 +218,7 @@ Circle(50) = {104, 31, 33};
 Circle(51) = {33, 31, 103};
 @endcode
 
-For the second circle, we use the alternate <code>Circle</code> entity, which requires the origin, radius,
-and starting and ending angle respectively.
-
-@code
-radius1 = .5;
-Circle(12) = {0.42, 2.0, 0, radius1, 0, 2*Pi};
-@endcode
+We follow the same procedure for the second circle.
 
 
 <h5>Plane surfaces</h5>
@@ -245,8 +240,8 @@ we are describing, whereas the second one is for the hole.
 This can easily be traced back by following along with the numbers in the braces.
 
 @code
-Curve Loop(1) = {40, -43, 14, 57, 59, 60, 58};
-Curve Loop(2) = {12};
+Curve Loop(1) = {40, -43, 10, 57, 59, 60, 58};
+Curve Loop(2) = {12, 13, 14, 15};
 Plane Surface(1) = {1, 2};
 @endcode
 
diff --git a/examples/step-49/example.geo b/examples/step-49/example.geo
index 050931a65f..cfe69c5a0b 100644
--- a/examples/step-49/example.geo
+++ b/examples/step-49/example.geo
@@ -14,7 +14,7 @@ Point(6) = {-0.98 - b, 0.2, 0, 1.0};
 Point(7) = {-0.98, 0, 0, 1.0};
 Point(8) = {-0.98 - b, -0.2, 0, 1.0};
 Point(9) = {-3.5, -0.2, 0, 1.0};
-Point(14) = {3.5, 0, 0, 1.0}; // Tip of slit on left hand side
+Point(10) = {3.5, 0, 0, 1.0}; // Tip of slit on left hand side
 
 // The 2 points below are for separating the left and right side of the mesh
 Point(36) = {-0.98, 3.36, 0, 1.0};
@@ -41,7 +41,7 @@ Line(6) = {6, 7};
 Line(7) = {7, 8};
 Line(8) = {8, 9};
 Line(9) = {9, 1};
-Line(14) = {7, 14}; // Line that bisects domain from top/bottom
+Line(10) = {7, 10}; // Line that bisects domain from top/bottom
 
 // Lines on the bottom/top domain
 Line(38) = {1, 37};
@@ -58,8 +58,8 @@ Line(52) = {2, 107};
 Line(53) = {107, 109};
 Line(54) = {109, 110};
 Line(55) = {110, 108};
-Line(56) = {108, 14};
-Line(57) = {14, 111};
+Line(56) = {108, 10};
+Line(57) = {10, 111};
 Line(58) = {112, 3};
 Line(59) = {111, 113};
 Line(60) = {113, 112};
@@ -74,29 +74,34 @@ Point(33) = {-2.1, -2.24, 0, 1.0}; // bottom point
 Point(103) = {-1.4, -1.54, 0, 1.0}; // right point
 Point(104) = {-2.8, -1.54, 0, 1.0}; // left point
 
-// Bottom left hole
+// Bottom left hole arcs
 Circle(48) = {103, 31, 32};
 Circle(49) = {32, 31, 104};
 Circle(50) = {104, 31, 33};
 Circle(51) = {33, 31, 103};
 
-// The upper right circle
+// Similarly, the upper right circle
 radius1 = .5;
 Point(19) = {0.42, 2.0, 0, 1.0}; // origin 
-Point(22) = {0.42, 2.0 + radius1, 0, 1.0}; // top point
-Point(23) = {0.42, 2.0 - radius1, 0, 1.0}; // bottom point
-Circle(12) = {0.42, 2.0, 0, radius1, 0, 2*Pi};
+Point(20) = {0.42, 2.0 - radius1, 0, 1.0};
+Point(21) = {0.42 + radius1, 2.0, 0, 1.0};
+Point(22) = {0.42, 2.0 + radius1, 0, 1.0};
+Point(23) = {0.42 - radius1, 2.0, 0, 1.0};
+Circle(12) = {20, 19, 21};
+Circle(13) = {21, 19, 22};
+Circle(14) = {22, 19, 23};
+Circle(15) = {23, 19, 20};
 
 //---------------------------------------------------------------------------
 // This section describes the "Plane Surfaces", i.e., the 2D surfaces for meshing
 
 // The surface of the top right partition
-Curve Loop(1) = {40, -43, 14, 57, 59, 60, 58};
-Curve Loop(2) = {12};
+Curve Loop(1) = {40, -43, 10, 57, 59, 60, 58};
+Curve Loop(2) = {12, 13, 14, 15};
 Plane Surface(1) = {1, 2};
 
 // Surface of the bottom right partition
-Curve Loop(3) = {39, 52, 53, 54, 55, 56, -14, -42};
+Curve Loop(3) = {39, 52, 53, 54, 55, 56, -10, -42};
 Plane Surface(2) = {3};
 
 // Surface of bottem left mesh