source: trunk/anuga_work/development/gareth/tests/more_plot_util.py

def plot_triangles(p):
    """ Add mesh triangles to a pyplot plot
    """
    for i in range(len(p.vols)):
        k1=p.vols[i][0]
        k2=p.vols[i][1]
        k3=p.vols[i][2]
        pyplot.plot([p.x[k1], p.x[k2], p.x[k3], p.x[k1]], [p.y[k1], p.y[k2], p.y[k3], p.y[k1]],'-',color='black')
        #pyplot.plot([p.x[k3], p.x[k2]], [p.y[k3], p.y[k2]],'-',color='black')
        #pyplot.plot([p.x[k3], p.x[k1]], [p.y[k3], p.y[k1]],'-',color='black')

def find_neighbours(p,ind):
    """ Find the triangles neighbouring triangle 'ind'
    """
    ind_nei=p.vols[ind]
    
    shared_nei0=p.vols[:,1]*0.0
    shared_nei1=p.vols[:,1]*0.0
    shared_nei2=p.vols[:,1]*0.0
    # Compute indices that match one of the vertices of triangle ind
    # Note: Each triangle can only match a vertex, at most, once
    for i in range(3):
        shared_nei0+=1*(p.x[p.vols[:,i]]==p.x[ind_nei[0]])*\
            1*(p.y[p.vols[:,i]]==p.y[ind_nei[0]])
        
        shared_nei1+=1*(p.x[p.vols[:,i]]==p.x[ind_nei[1]])*\
            1*(p.y[p.vols[:,i]]==p.y[ind_nei[1]])
        
        shared_nei2+=1*(p.x[p.vols[:,i]]==p.x[ind_nei[2]])*\
            1*(p.y[p.vols[:,i]]==p.y[ind_nei[2]])
    
    out=(shared_nei2 + shared_nei1 + shared_nei0)
    return((out==2).nonzero())

def calc_edge_elevations(p):
    pe_x=p.x*0.
    pe_y=p.y*0.
    pe_el=p.elev*0.

   
    # Compute coordinates + elevations 
    pe_x[p.vols[:,0]] = 0.5*(p.x[p.vols[:,1]] + p.x[p.vols[:,2]])
    pe_y[p.vols[:,0]] = 0.5*(p.y[p.vols[:,1]] + p.y[p.vols[:,2]])
    pe_el[p.vols[:,0]] = 0.5*(p.elev[p.vols[:,1]] + p.elev[p.vols[:,2]])
    
    pe_x[p.vols[:,1]] = 0.5*(p.x[p.vols[:,0]] + p.x[p.vols[:,2]])
    pe_y[p.vols[:,1]] = 0.5*(p.y[p.vols[:,0]] + p.y[p.vols[:,2]])
    pe_el[p.vols[:,1]] = 0.5*(p.elev[p.vols[:,0]] + p.elev[p.vols[:,2]])

    pe_x[p.vols[:,2]] = 0.5*(p.x[p.vols[:,0]] + p.x[p.vols[:,1]])
    pe_y[p.vols[:,2]] = 0.5*(p.y[p.vols[:,0]] + p.y[p.vols[:,1]])
    pe_el[p.vols[:,2]] = 0.5*(p.elev[p.vols[:,0]] + p.elev[p.vols[:,1]])

    return [pe_x, pe_y, pe_el]