def generate_stubs(self):
nx, ny = 11, 21
ratio = 3
# grid to be used as a mask
self.grid = [numpy.random.random(nx), numpy.random.random(ny)]
# create fields
self.fine = Field(x=numpy.ones(nx * ratio**2),
y=numpy.ones(ny * ratio**2),
values=numpy.random.rand(ny * ratio**2,
nx * ratio**2),
label='fine')
self.fine.x[::ratio**2] = self.grid[0][:]
self.fine.y[::ratio**2] = self.grid[1][:]
self.medium = Field(x=numpy.ones(nx * ratio),
y=numpy.ones(ny * ratio),
values=self.fine.values[::ratio, ::ratio] + 1.0,
label='medium')
self.medium.x[::ratio] = self.grid[0][:]
self.medium.y[::ratio] = self.grid[1][:]
self.coarse = Field(x=self.grid[0],
y=self.grid[1],
values=(self.fine.values[::ratio**2, ::ratio**2] +
(1.0 + ratio)),
label='coarse')
self.coarse2 = Field(
x=self.grid[0],
y=self.grid[1],
values=numpy.random.rand(*self.coarse.values.shape),
label='coarse2')
self.ratio = ratio
def test_three_grids(nx=11, ny=11, ratio=3, offset=0):
"""Computes the observed order of convergence using the solution on three
consecutive grids with constant refinement ratio.
The solution on the finest grid is random.
The solution of the medium grid is the finest solution restricted
and incremented by 1.
The solution of the coarsest grid is the finest solution restricted
and incremented by 1+ratio.
Therefore, no matter the norm used, we expect an order of convergence of 1.
Parameters
----------
nx, ny: integers, optional
Number of grid-points along each direction on the grid used a mask
to project the three solutions;
default: 11, 11.
ratio: integer, optional
Grid refinement ratio;
default: 3.
offset: integer, optional
Position of the coarsest grid relatively to the mask grid;
default: 0 (the coarsest solution is defined on the mask grid)
"""
# grid used as mask
grid = [numpy.random.random(nx), numpy.random.random(ny)]
# create fields
fine = Field(values=numpy.random.rand(ny * ratio**(offset + 2),
nx * ratio**(offset + 2)),
label='fine')
medium = Field(values=fine.values[::ratio, ::ratio] + 1.0, label='medium')
coarse = Field(values=fine.values[::ratio**2, ::ratio**2] + (1.0 + ratio),
label='coarse')
# fill nodal stations
coarse.x, coarse.y = numpy.ones(nx * ratio**offset), numpy.ones(
ny * ratio**offset)
coarse.x[::ratio**offset], coarse.y[::ratio**offset] = grid[0][:], grid[
1][:]
medium.x, medium.y = numpy.ones(nx * ratio**(offset + 1)), numpy.ones(
ny * ratio**(offset + 1))
medium.x[::ratio**(offset +
1)], medium.y[::ratio**(offset +
1)] = grid[0][:], grid[1][:]
fine.x, fine.y = numpy.ones(nx * ratio**(offset + 2)), numpy.ones(
ny * ratio**(offset + 2))
fine.x[::ratio**(offset +
2)], fine.y[::ratio**(offset +
2)] = grid[0][:], grid[1][:]
# compute observed order of convergence
p = convergence.get_observed_order(coarse, medium, fine, ratio, grid)
assert p == 1.0
p = convergence.get_observed_order(coarse,
medium,
fine,
ratio,
grid,
order=numpy.inf)
assert p == 1.0
def get_validation_data(path, Re):
"""Gets the validation data.
Parameters
----------
path: string
Path of the file containing the validation data.
Re: float
Reynolds number of the simulation.
Returns
-------
d: 2-tuple of Field objects
Contains stations and velocity values along center-lines
(vertical and horizontal).
"""
Re = str(int(round(Re)))
# column indices in file with experimental results
cols = {
'100': {
'u': 1,
'v': 7
},
'1000': {
'u': 2,
'v': 8
},
'3200': {
'u': 3,
'v': 9
},
'5000': {
'u': 4,
'v': 10
},
'10000': {
'u': 5,
'v': 11
}
}
with open(path, 'r') as infile:
y, u, x, v = numpy.loadtxt(infile,
dtype=float,
usecols=(0, cols[Re]['u'], 6,
cols[Re]['v']),
unpack=True)
return (Field(y=y, values=u,
label='x-velocity'), Field(x=x, values=v,
label='y-velocity'))
def __init__(self):
x, y = numpy.linspace(0.0, 10.0, 9*4), numpy.linspace(-1.0, 1.0, 9*5)
self.field = Field(x=x, y=y, time_step=0,
values=numpy.random.rand(y.size, x.size),
label='test')
self.restriction()
self.get_difference()
self.subtract()
def test_same_grid():
"""Computes the observed order of convergence using three solutions
on the same grid.
The first and last fields are a zero-solution; the middle solution is random.
Therefore, no matter the norm used, we expect an order of convergence of 0.
"""
# create grid
x, y = numpy.linspace(0.0, 1.0, 11), numpy.linspace(0.0, 10.0, 51)
# create three fields on the same grid
field1 = Field(x=x,
y=y,
time_step=0,
label='field1',
values=numpy.zeros((y.size, x.size)))
field2 = Field(x=x,
y=y,
time_step=0,
label='field2',
values=numpy.random.rand(y.size, x.size))
field3 = Field(x=x,
y=y,
time_step=0,
label='field3',
values=numpy.zeros((y.size, x.size)))
# compute observed order of convergence in L2-norm
p = convergence.get_observed_order(field1, field2, field3, 3,
[field1.x, field1.y])
assert p == 0.0
# compute observed order of convergence in Linf-norm
p = convergence.get_observed_order(field1,
field2,
field3,
3, [field1.x, field1.y],
order=numpy.inf)
assert p == 0.0
