示例#1
0
文件: Burgers.py 项目: yoonc5536/L2D
 def get_weno_grid(self, dx, dt,  T):
     left_boundary = self.x_low - dx * 0.5
     right_boundary = self.x_high + dx * 0.5
     ncells = int((self.x_high - self.x_low) / dx + 1.) # need to be very small
     num_t = int(T/dt + 1.)
     w = Weno3(left_boundary, right_boundary, ncells, self.flux, self.flux_deriv, self.max_flux_deriv, 
         dx = dx, dt = dt, num_t = num_t + 100)
     x_center = w.get_x_center()
     u0 = self.init_condition(x_center, self.args.initial_t)
     w.integrate(u0, T)
     solutions = w.u_grid[:num_t,:]
     return solutions
示例#2
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def get_weno_grid(init_condition,
                  dx=0.02,
                  dt=0.004,
                  T=0.8,
                  x_low=-1,
                  x_high=1,
                  boundary='periodic',
                  eta=0,
                  forcing=None,
                  ncells=None,
                  num_t=None,
                  flux_name='u2'):
    """
        dx: grid size. e.g. 0.02
        dt: time step size. e.g. 0.004
        T: evolve time. e.g. 1
        x_low: if the grid is in the range [-1,1], then x_low = -1.
        x_high: if the grid is in the range [-1,1], then x_low = 1.
        init_condition: a function that computes the initial values of u. e.g. the init func above.

        return: a grid of size num_t x num_x
            where   num_t = T/dt + 1
                    num_x = (x_high - x_low) / dx + 1
        """
    left_boundary = x_low - dx * 0.5
    right_boundary = x_high + dx * 0.5
    if ncells is None:
        ncells = int((x_high - x_low) / dx + 1.)  # need to be very small
    if num_t is None:
        num_t = int(T / dt + 1.)
    w = Weno3(left_boundary,
              right_boundary,
              ncells,
              lambda x: flux(val=x, flux=flux_name),
              lambda x: flux_deriv(val=x, flux=flux_name),
              lambda a, b: max_flux_deriv(a=a, b=b, flux=flux_name),
              dx=dx,
              dt=dt,
              num_t=num_t + 100,
              boundary=boundary,
              eta=eta,
              forcing=forcing)
    x_center = w.get_x_center()
    u0 = init_condition(x_center)
    w.integrate(u0, T, num_t=num_t)
    solutions = w.u_grid[:num_t, :]
    return solutions
示例#3
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def evolve(x_center, t, u0):
    dx = x_center[1] - x_center[0]
    cfl = 0.2
    left_boundary = x_center[0] - dx * 0.5
    right_boundary = x_center[-1] + dx * 0.5
    ncells = len(x_center)
    w = Weno3(left_boundary,
              right_boundary,
              ncells,
              flux,
              flux_deriv,
              max_flux_deriv,
              dx=dx,
              dt=dx * cfl,
              cfl_number=cfl,
              record=False)
    return w.integrate(u0, t)
def evolve(x_center, u0, t, animation=0):
    dx = x_center[1] - x_center[0]
    cfl = 0.2
    left_boundary = x_center[0] - dx * 0.5
    right_boundary = x_center[-1] + dx * 0.5
    ncells = len(x_center)
    dt = dx * cfl
    evolve_num = int(t / dt)
    w = Weno3(left_boundary,
              right_boundary,
              ncells,
              flux,
              flux_deriv,
              max_flux_deriv,
              dx=dx,
              dt=dx * cfl,
              cfl_number=cfl)
    w.integrate(u0, t)
    solutions = w.u_grid[:evolve_num + 1, :]
    if animation:
        return solutions
    else:
        return solutions[-1]