added keepdims=False option to project_stereographic

This commit is contained in:
Philip Eisenlohr 2021-02-27 18:32:53 -05:00
parent ea763fd941
commit 175d724ded
2 changed files with 30 additions and 15 deletions

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@ -193,7 +193,7 @@ def scale_to_coprime(v):
return m
def project_stereographic(vector,normalize=False,direction='z'):
def project_stereographic(vector,direction='z',normalize=True,keepdims=False):
"""
Apply stereographic projection to vector.
@ -201,23 +201,37 @@ def project_stereographic(vector,normalize=False,direction='z'):
----------
vector : numpy.ndarray of shape (...,3)
Vector coordinates to be projected.
normalize : bool
Ensure unit length for vector. Defaults to False.
direction : str or int
Projection direction 'x' | 0, 'y' | 1, or 'z' | 2.
Defaults to 'z'.
normalize : bool
Ensure unit length of input vector. Defaults to True.
keepdims : bool
Maintain three-dimensional output coordinates.
Default two-dimensional output uses right-handed frame spanned by
the next and next-next axis relative to the projection direction,
e.g. x-y when projecting along z and z-x when projecting along y.
Returns
-------
coordinates : numpy.ndarray of shape (...,3)
coordinates : numpy.ndarray of shape (...,2 | 3)
Projected coordinates.
Examples
--------
>>> project_stereographic(np.ones(3))
[0.3660254, 0.3660254]
>>> project_stereographic(np.ones(3),direction='x',normalize=False,keepdims=True)
[0, 0.5, 0.5]
>>> project_stereographic([0,1,1],direction='y',normalize=True,keepdims=False)
[0.41421356, 0]
"""
shift = 2-('xyzXYZ'.index(direction)%3 if isinstance(direction,str) else int(direction))
v_ = np.roll(vector/np.linalg.norm(vector,axis=-1,keepdims=True) if normalize else vector,
shift,axis=-1)
return np.roll(np.block([v_[...,:2]/(1+np.abs(v_[...,2:3])),np.zeros_like(v_[...,2:3])]),
-shift,axis=-1)
-shift if keepdims else 0,axis=-1)[...,:3 if keepdims else 2]
def execution_stamp(class_name,function_name=None):

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@ -49,17 +49,18 @@ class TestUtil:
dist_sampled = np.histogram(centers[selected],bins)[0]/N_samples*np.sum(dist)
assert np.sqrt(((dist - dist_sampled) ** 2).mean()) < .025 and selected.shape[0]==N_samples
@pytest.mark.parametrize('point,normalize,direction,answer',
@pytest.mark.parametrize('point,direction,normalize,keepdims,answer',
[
([1,0,0],False,'z',[1,0,0]),
([1,0,0],True, 'z',[1,0,0]),
([0,1,1],False,'z',[0,0.5,0]),
([0,1,1],True, 'y',[0,0,0.41421356]),
([1,1,1],False,'x',[0,0.5,0.5]),
([1,1,1],True, 'y',[0.3660254, 0,0.3660254]),
([1,0,0],'z',False,True, [1,0,0]),
([1,0,0],'z',True, False,[1,0]),
([0,1,1],'z',False,True, [0,0.5,0]),
([0,1,1],'y',True, False,[0.41421356,0]),
([1,1,0],'x',False,False,[0.5,0]),
([1,1,1],'y',True, True, [0.3660254, 0,0.3660254]),
])
def test_project_stereographic(self,point,normalize,direction,answer):
assert np.allclose(util.project_stereographic(np.array(point),normalize=normalize,direction=direction),answer)
def test_project_stereographic(self,point,direction,normalize,keepdims,answer):
assert np.allclose(util.project_stereographic(np.array(point),direction=direction,
normalize=normalize,keepdims=keepdims),answer)
@pytest.mark.parametrize('fro,to,mode,answer',
[