def test_grid():
input = CoordinateSystem('ij', 'input')
output = CoordinateSystem('xy', 'output')
def f(ij):
i = ij[:,0]
j = ij[:,1]
return np.array([i**2+j,j**3+i]).T
cmap = CoordinateMap(input, output, f)
grid = Grid(cmap)
eval = ArrayCoordMap.from_shape(cmap, (50,40))
assert_true(np.allclose(grid[0:50,0:40].values, eval.values))
def test_grid32():
# Check that we can use a float32 input and output
uv32 = CoordinateSystem('uv', 'input', np.float32)
xyz32 = CoordinateSystem('xyz', 'output', np.float32)
surface32 = CoordinateMap(uv32, xyz32, parametric_mapping)
g = Grid(surface32)
xyz_grid = g[-1:1:201j, -1:1:101j]
x, y, z = xyz_grid.transposed_values
yield assert_equal, x.shape, (201, 101)
yield assert_equal, y.shape, (201, 101)
yield assert_equal, z.shape, (201, 101)
yield assert_equal, x.dtype, np.dtype(np.float32)
def test_eval_slice():
input = CoordinateSystem('ij', 'input')
output = CoordinateSystem('xy', 'output')
def f(ij):
i = ij[:,0]
j = ij[:,1]
return np.array([i**2+j,j**3+i]).T
cmap = CoordinateMap(input, output, f)
cmap = CoordinateMap(input, output, f)
grid = Grid(cmap)
e = grid[0:50,0:40]
ee = e[0:20:3]
yield assert_equal, ee.shape, (7,40)
yield assert_equal, ee.values.shape, (280,2)
yield assert_equal, ee.transposed_values.shape, (2,7,40)
ee = e[0:20:2,3]
yield assert_equal, ee.values.shape, (10,2)
yield assert_equal, ee.transposed_values.shape, (2,10)
yield assert_equal, ee.shape, (10,)
def test_grid32_c128():
# Check that we can use a float32 input and complex128 output
uv32 = CoordinateSystem('uv', 'input', np.float32)
xyz128 = CoordinateSystem('xyz', 'output', np.complex128)
def par_c128(x):
return parametric_mapping(x).astype(np.complex128)
surface = CoordinateMap(uv32, xyz128, par_c128)
g = Grid(surface)
xyz_grid = g[-1:1:201j, -1:1:101j]
x, y, z = xyz_grid.transposed_values
yield assert_equal, x.shape, (201, 101)
yield assert_equal, y.shape, (201, 101)
yield assert_equal, z.shape, (201, 101)
yield assert_equal, x.dtype, np.dtype(np.complex128)
def load_npz(filename):
"""
Load an .npz Image, this .npz file must have at least two arrays
* data: the data array
* dimnames: the dimension names of the corresponding grid
* affine: the affine transformation of grid
The remaining arrays of .npz file are stored as the 'extra' attribute of the Image.
"""
npzobj = np.load(filename)
im = Image(npzobj['data'], CoordinateMap.from_affine(Affine(npzobj['affine']),
list(npzobj['dimnames']),
npzobj['data'].shape))
im.extra = {}
for f in npzobj.files:
if f not in ['affine', 'dimnames', 'data']:
im.extra[f] = npzobj[f]
return im
return o
"""
Let's check that indeed this is a parametrization of that surface
"""
def implicit(vals):
x = vals[:, 0]
y = vals[:, 1]
z = vals[:, 2]
return x**2 - y**2 * z**2 + z**3
surface_param = CoordinateMap(uv, xyz, parametric_mapping)
def test_surface():
assert np.allclose(
implicit(parametric_mapping(np.random.standard_normal((40, 2)))), 0)
def test_grid():
g = Grid(surface_param)
xyz_grid = g[-1:1:201j, -1:1:101j]
x, y, z = xyz_grid.transposed_values
yield assert_equal, x.shape, (201, 101)
yield assert_equal, y.shape, (201, 101)
yield assert_equal, z.shape, (201, 101)