id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc 193,"Mesh generation (and consequently, timestepping) differs between Linux and Windows.",ole,Nick,"The same script and same ANUGA version generates slightly different meshes on different platforms. The example anuga_work/development/demos/island.py shows this. I have checked in the generated meshes using the names island_linux.msh and island_windows.msh. On either platform the timestepping is dramatically different depending on which mesh is being used. Here's some output: Using the Linux mesh {{{ Mesh statistics: Number of triangles = 7208 Extent [m]: x in [0.000000, 100.000000] y in [0.000000, 100.000000] Areas [m^2]: A in [0.644829, 9.596606] number of distinct areas: 7208 Histogram: [0.644829, 1.540006[: 5421 [1.540006, 2.435184[: 1610 [2.435184, 3.330362[: 37 [3.330362, 4.225539[: 35 [4.225539, 5.120717[: 37 [5.120717, 6.015895[: 21 [6.015895, 6.911073[: 18 [6.911073, 7.806250[: 11 [7.806250, 8.701428[: 8 [8.701428, 9.596606]: 10 Percentiles (10%): 720 triangles in [0.644829, 0.931708] 720 triangles in [0.931708, 1.017388] 720 triangles in [1.017388, 1.096717] 720 triangles in [1.096717, 1.173627] 720 triangles in [1.173627, 1.265768] 720 triangles in [1.265768, 1.367499] 720 triangles in [1.367499, 1.473311] 720 triangles in [1.473311, 1.605096] 720 triangles in [1.605096, 1.788979] 720 triangles in [1.788979, 9.002288] 8 triangles in [9.002288, 9.596606] Boundary: Number of boundary segments == 230 Boundary tags == ['top', 'right', 'bottom', 'left'] ------------------------------------------------ Time = 0.0000, steps=0 (0) Time = 1.0000, delta t in [0.00490999, 0.02104604], steps=120 (0) Time = 2.0000, delta t in [0.00488622, 0.00548481], steps=194 (0) }}} Using the Windows mesh {{{ Mesh statistics: Number of triangles = 7210 Extent [m]: x in [0.000000, 100.000000] y in [0.000000, 100.000000] Areas [m^2]: A in [0.629728, 9.479879] number of distinct areas: 7210 Histogram: [0.629728, 1.514743[: 5259 [1.514743, 2.399758[: 1773 [2.399758, 3.284773[: 40 [3.284773, 4.169788[: 38 [4.169788, 5.054803[: 37 [5.054803, 5.939819[: 16 [5.939819, 6.824834[: 21 [6.824834, 7.709849[: 9 [7.709849, 8.594864[: 10 [8.594864, 9.479879]: 7 Percentiles (10%): 721 triangles in [0.629728, 0.938614] 721 triangles in [0.938614, 1.023260] 721 triangles in [1.023260, 1.099714] 721 triangles in [1.099714, 1.180817] 721 triangles in [1.180817, 1.270424] 721 triangles in [1.270424, 1.373040] 721 triangles in [1.373040, 1.479134] 721 triangles in [1.479134, 1.602771] 721 triangles in [1.602771, 1.780142] 721 triangles in [1.780142, 9.479879] Boundary: Number of boundary segments == 232 Boundary tags == ['top', 'right', 'bottom', 'left'] ------------------------------------------------ Time = 0.0000, steps=0 (0) Time = 1.0000, delta t in [0.00046156, 0.02104604], steps=947 (0) Time = 2.0000, delta t in [0.00040646, 0.00047853], steps=2306 (0) }}} Can you investigate 1: Why this is? 2: If there is a way of avoiding the mesh condition that creates the degenerate timestepping (194 steps/s to 2306 steps/s)? This problem was produced in changeset:4725 Ta Ole ",defect,closed,normal,,Functionality and features,,normal,wontfix,,