fix curve

examples/sediment_meander_2d/meander.geo

@@ -0,0 +1,52 @@
+Point (1) = {0, -9, 0, 0.1};
+Point (101) = {0.5, -9, 0, 0.25};
+Point (2) = {0, 2.5, 0, 0.1};
+Point (3) = {1, -9, 0, 0.1};
+Point (4) = {1, 2.5, 0, 0.1};
+Point (14) = {0.5, 2.5, 0, 0.25};
+Point (5) = {8, 2.5, 0, 0.1};
+Point (12) = {8.5, 2.5, 0, 0.25};
+Point (6) = {9, 2.5, 0, 0.1};
+Point (7) = {8, -9, 0, 0.1};
+Point (107) = {8.5, -9, 0, 0.25};
+Point (8) = {9, -9, 0, 0.1};
+Point (9) = {4.5, 7,0, 0.1};
+Point (10) = {4.5, 2.5, 0, 0.1};
+Point (11) = {4.5, 6, 0, 0.1};
+Point (13) = {4.5, 6.5, 0, 0.25};
+Circle (9) = {2, 10, 9};
+Circle (10) = {4, 10, 11};
+Circle (11) = {12, 10, 13};
+Circle (12) = {13, 10, 14};
+Circle (3) = {9, 10,  6};
+Circle (4) = {11, 10, 5};
+Line (5) = {1,2};
+Line (6) = {3, 4};
+Line (7) = {7, 5};
+Line (8) = {8, 6};
+
+Line(34) = {101, 14};
+Line(35) = {101, 1};
+Line(36) = {3, 101};
+Line(37) = {12, 107};
+Line(38) = {7, 107};
+Line(39) = {8, 107};
+
+
+Physical Line(1) = {35, 36};
+Physical Line(2) = {38, 39};
+Physical Line(3) = {5, 6, 7, 8};
+Physical Line(4) = {3, 9};
+Physical Line(5) = {4, 10};
+
+Line Loop (20) = {35, 5, 9, 3, -8, 39, -37, 11, 12, -34};
+Plane Surface(16) = {20};
+Physical Surface(200) = {20};
+
+Line Loop (30) = {-36, 6, 10, 4, -7, 38, -37, 11, 12, -34};
+Plane Surface(20) = {30};
+Physical Surface(100) = {16};
+
+Field[1] = MathEval;
+Field[1].F = "0.2";
+Background Field = 1;