1 | #! /usr/bin/python |
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2 | |
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3 | """ |
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4 | Boundaries - specific to the shallow water wave equation |
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5 | """ |
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6 | __author__="Stephen Roberts" |
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7 | __date__ ="$05/06/2010 5:44:05 PM$" |
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8 | |
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9 | from generic_domain import * |
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10 | |
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11 | class Dirichlet_boundary(Boundary): |
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12 | """Dirichlet boundary returns constant values for the |
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13 | conserved quantities |
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14 | """ |
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15 | |
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16 | def __init__(self, quantities=None): |
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17 | Boundary.__init__(self) |
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18 | |
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19 | if quantities is None: |
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20 | msg = 'Must specify one value for each evolved quantity, w,uh,z,h,u' |
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21 | raise msg |
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22 | |
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23 | self.quantities=numpy.array(quantities, numpy.float) |
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24 | |
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25 | def __repr__(self): |
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26 | return 'Dirichlet boundary (%s)' %self.quantities |
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27 | |
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28 | def evaluate(self, vol_id=None, edge_id=None): |
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29 | return self.quantities |
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30 | |
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31 | |
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32 | class Reflective_boundary(Boundary): |
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33 | """Reflective boundary returns same conserved quantities as |
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34 | those present in its neighbour volume but reflected. |
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35 | |
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36 | This class is specific to the shallow water equation as it |
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37 | works with the momentum quantities assumed to be the second |
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38 | and third conserved quantities. |
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39 | """ |
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40 | |
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41 | def __init__(self, domain = None): |
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42 | Boundary.__init__(self) |
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43 | |
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44 | if domain is None: |
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45 | msg = 'Domain must be specified for reflective boundary' |
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46 | raise msg |
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47 | |
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48 | #Handy shorthands |
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49 | self.normals = domain.normals |
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50 | self.stage = domain.quantities['stage'].vertex_values |
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51 | self.xmom = domain.quantities['xmomentum'].vertex_values |
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52 | self.bed = domain.quantities['elevation'].vertex_values |
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53 | self.height = domain.quantities['height'].vertex_values |
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54 | self.velocity = domain.quantities['velocity'].vertex_values |
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55 | |
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56 | |
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57 | self.quantities = numpy.zeros(5, numpy.float) |
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58 | |
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59 | def __repr__(self): |
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60 | return 'Reflective_boundary' |
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61 | |
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62 | |
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63 | def evaluate(self, vol_id, edge_id): |
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64 | """Reflective boundaries reverses the outward momentum |
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65 | of the volume they serve. |
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66 | """ |
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67 | |
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68 | q = self.quantities |
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69 | q[0] = self.stage[vol_id, edge_id] |
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70 | q[1] = -self.xmom[vol_id, edge_id] |
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71 | q[2] = self.bed[vol_id, edge_id] |
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72 | q[3] = self.height[vol_id, edge_id] |
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73 | q[4] = -self.velocity[vol_id, edge_id] |
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74 | |
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75 | #normal = self.normals[vol_id,edge_id] |
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76 | |
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77 | return q |
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78 | |
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79 | |
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80 | |
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81 | |
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82 | if __name__ == "__main__": |
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83 | print "Hello World"; |
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