def gaussian(C=1, Nx=50, animate=True, T=2, loc=0):
"""Gaussian bell as initial condition."""
L = 1.
c = 1
def I(x):
return exp(-0.5 * ((x - loc) / 0.05)**2)
bc_left = 'dudx=0' if loc == 0 else 'open'
dt = (L / Nx) / c # choose the stability limit with given Nx
cpu = viz(I,
None,
None,
c,
L,
dt,
C,
T,
umin=-0.2,
umax=1,
animate=animate,
bc_left=bc_left)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([plug, gaussian], sys.argv)
eval(cmd)
#print sp.latex(b, mode='plain')
if symbolic:
c = A.LUsolve(b)
else:
c = np.linalg.solve(A, b)
print 'c:\n', c
print 'Plain interpolation/collocation:'
x = sp.Symbol('x')
f = sp.lambdify([x], f, modules='numpy')
try:
f_at_nodes = [f(xc) for xc in nodes]
except NameError as e:
raise NameError('numpy does not support special function:\n%s' % e)
print f_at_nodes
if not symbolic and filename is not None:
xf = np.linspace(Omega[0], Omega[1], 10001)
U = np.asarray(c)
xu, u = u_glob(U, elements, nodes)
plt.plot(xu, u, '-',
xf, f(xf), '--')
plt.legend(['u', 'f'])
plt.savefig(filename + '.pdf')
plt.savefig(filename + '.png')
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([phi_r, u_glob, element_matrix, element_vector, exemplify_element_matrix_vector, assemble, approximate], sys.argv)
x = sp.Symbol('x') # needed in eval when expression f contains x
eval(cmd)
return 0
else:
return 1
cpu = viz(I, None, None, c, L, Nx, C, T,
umin=-1.1, umax=1.1, animate=animate)
def test_plug():
"""Check that an initial plug is correct back after one period."""
L = 1
I = lambda x: 0 if abs(x-L/2.0) > 0.1 else 1
u_s, x, t, cpu = solver(
I=I, V=None, f=None, c=0.5, L=L,
Nx=50, C=1, T=4, user_action=None)
u_v, x, t, cpu = solver(
I=I, V=None, f=None, c=0.5, L=L,
Nx=50, C=1, T=4, user_action=None)
diff = abs(u_s - u_v).max()
nt.assert_almost_equal(diff, 0, places=13)
u_0 = array([I(x_) for x_ in x])
diff = abs(u_s - u_0).max()
nt.assert_almost_equal(diff, 0, places=13)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_plug, plug], sys.argv)
eval(cmd)
return cos(pi*(x-xc)/a) \
if xc - 0.5*a <= x <= xc + 0.5*a else 0
else:
raise ValueError('Wrong pulse_tp="%s"' % pulse_tp)
def c(x):
return c_0/slowness_factor \
if medium[0] <= x <= medium[1] else c_0
umin=-0.5; umax=1.5*I(xc)
casename = '%s_Nx%s_sf%s' % \
(pulse_tp, Nx, slowness_factor)
action = PlotMediumAndSolution(
medium, casename=casename, umin=umin, umax=umax,
every_frame=every_frame, screen_movie=animate)
solver(I=I, V=None, f=None, c=c, U_0=None, U_L=None,
L=L, Nx=Nx, C=C, T=T,
user_action=action, version=version,
dt_safety_factor=1)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_quadratic, test_plug, pulse,
moving_end,], sys.argv)
eval(cmd)
raw_input()
def test_mms():
domain = UnitDomain([10])
alpha = lambda u: 1.0 + pow(u, 2.0)
#f = Constant(0.0)
I = Expression("cos(pi*x[0])")
p = 1
rho = 1.0
dt = 0.05
T = 0.5
f = Expression(
"-rho*pow(x[0],3)/3 + rho*pow(x[0],2)/2 + 8*pow(t,3)*pow(x[0],7)/9 - 28*pow(t,3)*pow(x[0],6)/9+7*pow(t,3)*pow(x[0],5)/2 - 5*pow(t,3)*pow(x[0],4)/4 + 2*t*x[0] - t",
t=0.0,
rho=rho)
def u_e(x, t):
return (x**2.0) * (0.5 - x / 3.0) * t
def action(t, u):
for x in range(10):
assert_almost_equal(u_e(x, t), u.vector().array()[x])
solver(dt, T, domain, p, rho, alpha, f, I, action)
if __name__ == "__main__":
import sys
from scitools.misc import function_UI
cmd = function_UI([solver, test_convergance_rate, test_mms], sys.argv)
eval(cmd)
elif plot_method == 3:
print 'Experimental 3D matplotlib...under development...'
#plt.clf()
ax = fig.add_subplot(111, projection='3d')
u_surf = ax.plot_surface(xv, yv, u, alpha=0.3)
#ax.contourf(xv, yv, u, zdir='z', offset=-100, cmap=cm.coolwarm)
#ax.set_zlim(-1, 1)
# Remove old surface before drawing
if u_surf is not None:
ax.collections.remove(u_surf)
plt.draw()
time.sleep(1)
if plot_method > 0:
time.sleep(0) # pause between frames
if save_plot:
filename = 'tmp_%04d.png' % n
savefig(filename) # time consuming!
Nx = 20; Ny = 20; T = 30
dt, cpu = solver(I, None, None, b, q, Lx, Ly, Nx, Ny, -1, T,
user_action=plot_u, version=version)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([run_efficiency_tests,
run_Gaussian,
run_physical_problem, ], sys.argv)
eval(cmd)
time.sleep(0) # pause between frames
filename = 'tmp_%04d.png' % n
#savefig(filename) # time consuming - dropped
Nx = 40
Ny = 40
T = 20
dt = solver(I,
None,
None,
c,
Lx,
Ly,
Nx,
Ny,
0,
T,
user_action=plot_u,
version=version)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([
test_quadratic,
run_efficiency_tests,
run_Gaussian,
], sys.argv)
eval(cmd)
E2 = []
h = []
for _N in N:
psi, points = Lagrange_polynomials_01(x, _N)
u = interpolation(f, psi, points)
un = sm.lambdify([x], u, modules='numpy')
ucoor = un(xcoor)
e = fcoor - ucoor
Einf.append(e.max())
E2.append(np.sqrt(np.sum(e*e/e.size)))
h.append(1./_N)
print Einf
print E2
print h
print N
# Assumption: error = CN**(-N)
print 'convergence rates:'
for i in range(len(E2)):
C1 = E2[i]/(N[i]**(-N[i]/2))
C2 = Einf[i]/(N[i]**(-N[i]/2))
print N[i], C1, C2
# Does not work properly...
if __name__ == '__main__':
functions = \
[eval(fname) for fname in dir() if fname.startswith('run_')]
from scitools.misc import function_UI
cmd = function_UI(functions, sys.argv)
eval(cmd)
"""Plug profile as initial condition."""
L = 1.
c = 1
I = lambda x: 1 if abs(x-loc) < 0.1 else 0
bc_left = 'dudx=0' if loc == 0 else 'open'
dt = (L/Nx)/c # choose the stability limit with given Nx
cpu = viz(I, None, None, c, L, dt, C, T,
umin=-0.3, umax=1.1, animate=animate,
bc_left=bc_left)
def gaussian(C=1, Nx=50, animate=True, T=2, loc=0):
"""Gaussian bell as initial condition."""
L = 1.
c = 1
def I(x):
return exp(-0.5*((x-loc)/0.05)**2)
bc_left = 'dudx=0' if loc == 0 else 'open'
dt = (L/Nx)/c # choose the stability limit with given Nx
cpu = viz(I, None, None, c, L, dt, C, T,
umin=-0.2, umax=1, animate=animate, bc_left=bc_left)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([plug, gaussian], sys.argv)
eval(cmd)
else:
raise ValueError('Wrong pulse_tp="%s"' % pulse_tp)
def c(x):
return c_0/slowness_factor \
if medium[0] <= x <= medium[1] else c_0
umin=-0.5; umax=1.5*I(xc)
casename = '%s_Nx%s_sf%s' % \
(pulse_tp, Nx, slowness_factor)
action = PlotMediumAndSolution(
medium, casename=casename, umin=umin, umax=umax,
every_frame=every_frame, screen_movie=animate)
solver(I=I, V=None, f=None, c=c, U_0=None, U_L=None,
L=L, Nx=Nx, C=C, T=T,
user_action=action, version=version,
dt_safety_factor=1)
if __name__ == '__main__':
import sys
# Enable running the various functions from the command line
from scitools.misc import function_UI
cmd = function_UI([test_quadratic, test_plug, pulse,
demo_BC_plug, demo_BC_gaussian, moving_end,],
sys.argv)
eval(cmd)
raw_input()
"""Gaussian peak at (Lx/2, Ly/2)."""
return exp(-0.5*(x-Lx/2.0)**2 - 0.5*(y-Ly/2.0)**2)
def plot_u(u, x, xv, y, yv, t, n):
if t[n] == 0:
time.sleep(2)
if plot_method == 1:
mesh(x, y, u, title='t=%g' % t[n], zlim=[-1,1],
caxis=[-1,1])
elif plot_method == 2:
surfc(xv, yv, u, title='t=%g' % t[n], zlim=[-1, 1],
colorbar=True, colormap=hot(), caxis=[-1,1],
shading='flat')
if plot_method > 0:
time.sleep(0) # pause between frames
filename = 'tmp_%04d.png' % n
#savefig(filename) # time consuming - dropped
Nx = 40; Ny = 40; T = 20
dt = solver(I, None, None, c, Lx, Ly, Nx, Ny, 0, T,
user_action=plot_u, version=version)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_quadratic, run_efficiency_tests,
run_Gaussian, ], sys.argv)
eval(cmd)
u_s, x, t, cpu = solver(I=I,
V=None,
f=None,
c=0.5,
L=L,
Nx=50,
C=1,
T=4,
user_action=None)
u_v, x, t, cpu = solver(I=I,
V=None,
f=None,
c=0.5,
L=L,
Nx=50,
C=1,
T=4,
user_action=None)
diff = abs(u_s - u_v).max()
nt.assert_almost_equal(diff, 0, places=13)
u_0 = array([I(x_) for x_ in x])
diff = abs(u_s - u_0).max()
nt.assert_almost_equal(diff, 0, places=13)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_plug, plug], sys.argv)
eval(cmd)
Nx = 80
cpu = viz(I, None, None, c, U_0, U_L, L, Nx, C, T,
umin=-1.1, umax=1.1, version='scalar', animate=True)
# Convergence study
def action(u, x, t, n):
e = abs(u - exact(x, t[n])).max()
errors_in_time.append(e)
E = []
dt = []
Nx_values = [10, 20, 40, 80, 160]
for Nx in Nx_values:
errors_in_time = []
solver(I, None, None, c, U_0, U_L, L, Nx, C, T,
user_action=action, version='scalar')
E.append(max(errors_in_time))
_dx = L/Nx
_dt = C*_dx/c
dt.append(_dt)
print dt[-1], E[-1]
return dt, E
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_quadratic, test_plug, plug,
gaussian, sincos, guitar,
moving_end,], sys.argv)
eval(cmd)
def sines(x, y, Nx, Ny):
return [sym.sin(sym.pi*(i+1)*x)*sym.sin(sym.pi*(j+1)*y)
for i in range(Nx+1) for j in range(Ny+1)]
def taylor(x, y, Nx, Ny):
return [x**i*y**j for i in range(Nx+1) for j in range(Ny+1)]
# ----------------------------------------------------------------------
def run_linear():
f = (1+x**2)*(1+2*y**2)
psi = taylor(x, y, 1, 1)
print psi
Omega = [[0, 2], [0, 2]]
u = least_squares(f, psi, Omega)
comparison_plot(f, u, Omega, plotfile='approx2D_bilinear')
print '\n\n**** Include second order terms:'
psi = taylor(x, y, 2, 2)
u = least_squares(f, psi, Omega)
if __name__ == '__main__':
functions = \
[eval(fname) for fname in dir() if fname.startswith('run_')]
from scitools.misc import function_UI
cmd = function_UI(functions, sys.argv)
eval(cmd)
E = sqrt(sum(e**2)/u.vector().array().size)
assert_almost_equal(E, pow(dt,p))
def test_mms():
domain = UnitDomain([10])
alpha = lambda u: 1.0 + pow(u,2.0)
#f = Constant(0.0)
I = Expression("cos(pi*x[0])")
p = 1
rho = 1.0
dt = 0.05
T = 0.5
f = Expression("-rho*pow(x[0],3)/3 + rho*pow(x[0],2)/2 + 8*pow(t,3)*pow(x[0],7)/9 - 28*pow(t,3)*pow(x[0],6)/9+7*pow(t,3)*pow(x[0],5)/2 - 5*pow(t,3)*pow(x[0],4)/4 + 2*t*x[0] - t",t=0.0,rho=rho)
def u_e(x,t):
return (x**2.0)*(0.5 - x/3.0)*t
def action(t, u):
for x in range(10):
assert_almost_equal(u_e(x,t),u.vector().array()[x])
solver(dt, T, domain, p, rho, alpha, f, I, action)
if __name__ == "__main__":
import sys
from scitools.misc import function_UI
cmd = function_UI([solver,
test_convergance_rate,
test_mms], sys.argv)
eval(cmd)
if isinstance(X, np.ndarray):
z = np.zeros(len(X))
if d == 0:
return 0 + z
elif d == 1:
if r == 0:
return -0.5 + z
elif r == 1:
return 0.5 + z
elif d == 2:
if r == 0:
return X - 0.5
elif r == 1:
return -2*X
elif r == 2:
return X + 0.5
else:
print 'dphi_r only supports d=0,1,2, not %d' % d
return None
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI(
[phi_r, u_glob, element_matrix, element_vector,
exemplify_element_matrix_vector, assemble, approximate],
sys.argv)
x = sym.Symbol('x') # needed in eval when expression f contains x
eval(cmd)
solver(I=I,
V=None,
f=None,
c=c,
U_0=None,
U_L=None,
L=L,
Nx=Nx,
C=C,
T=T,
user_action=action,
version=version,
dt_safety_factor=1)
if __name__ == '__main__':
import sys
# Enable running the various functions from the command line
from scitools.misc import function_UI
cmd = function_UI([
test_quadratic,
test_plug,
pulse,
demo_BC_plug,
demo_BC_gaussian,
moving_end,
], sys.argv)
eval(cmd)
raw_input()
Nx = 80
cpu = viz(I, None, None, c, U_0, U_L, L, Nx, C, T,
umin=-1.1, umax=1.1, version='scalar', animate=True)
# Convergence study
def action(u, x, t, n):
e = abs(u - exact(x, t[n])).max()
errors_in_time.append(e)
E = []
dt = []
Nx_values = [10, 20, 40, 80, 160]
for Nx in Nx_values:
errors_in_time = []
solver(I, None, None, c, U_0, U_L, L, Nx, C, T,
user_action=action, version='scalar')
E.append(max(errors_in_time))
_dx = L/Nx
_dt = C*_dx/c
dt.append(_dt)
print dt[-1], E[-1]
return dt, E
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([test_quadratic, test_plug, plug,
gaussian, sincos, guitar,
moving_end,], sys.argv)
eval(cmd)
umax=umax,
every_frame=every_frame,
screen_movie=animate)
solver(I=I,
V=None,
f=None,
c=c,
U_0=None,
U_L=None,
L=L,
Nx=Nx,
C=C,
T=T,
user_action=action,
version=version,
dt_safety_factor=1)
if __name__ == '__main__':
import sys
from scitools.misc import function_UI
cmd = function_UI([
test_quadratic,
test_plug,
pulse,
moving_end,
], sys.argv)
eval(cmd)
raw_input()
