Add methods to turn SC into MOSAs

lisainstrument/indexing.py

@@ -8,13 +8,10 @@ Authors:
 """
 
 import numpy as np
-import logging
 
-logger = logging.getLogger(__name__)
 
-
-"""List of MOSA index as two-figure strings, in the order they are used in an array."""
 MOSAS = ['12', '23', '31', '13', '32', '21']
+SC = ['1', '2', '3']
 
 
 def index2mosa(index):
@@ -55,10 +52,6 @@ MOSA32 = mosa2index('32')
 MOSA21 = mosa2index('21')
 
 
-"""List of SC indices as one-figure strings, in the order they are used in an array."""
-SC = ['1', '2', '3']
-
-
 def index2sc(index):
     """Return SC index associated with a given array index.
 
@@ -180,3 +173,64 @@ def mosa2sc(mosa):
     if str(mosa) not in MOSAS:
         raise ValueError(f"invalid MOSA index '{mosa}'")
     return str(mosa)[0]
+
+
+def sc2leftdistant(sc):
+    """Return index of left distant SC.
+
+    Args:
+        sc: SC index, as one-figure string or integer
+    """
+    if str(sc) not in SC:
+        raise ValueError(f"invalid SC index '{sc}'")
+    return rotate(sc, nrot=1)
+
+
+def sc2rightdistant(sc):
+    """Return index of right distant SC.
+
+    Args:
+        sc: SC index, as one-figure string or integer
+    """
+    if str(sc) not in SC:
+        raise ValueError(f"invalid SC index '{sc}'")
+    return rotate(sc, nrot=-1)
+
+
+def sc2leftmosa(sc):
+    """Return left MOSA index.
+
+    Args:
+        sc: SC index, as one-figure string or integer
+    """
+    if str(sc) not in SC:
+        raise ValueError(f"invalid SC index '{sc}'")
+    return f'{sc}{sc2leftdistant(sc)}'
+
+
+def sc2rightmosa(sc):
+    """Return right MOSA index.
+
+    Args:
+        sc: SC index, as one-figure string or integer
+    """
+    if str(sc) not in SC:
+        raise ValueError(f"invalid SC index '{sc}'")
+    return f'{sc}{sc2rightdistant(sc)}'
+
+
+def sc2bothmosas(x):
+    """Broadcast a SC array to a MOSA array.
+
+    We broadcast by assuming the same values for both MOSAs of each SC.
+
+    Args:
+        sc: SC array
+
+    Returns:
+        A MOSA array.
+    """
+    if not isinstance(x, np.ndarray) or x.shape[0] != 3:
+        raise TypeError("invalid SC array")
+    sc_mosas = [sc2index(mosa2sc(mosa)) for mosa in MOSAS]
+    return x[sc_mosas]

tests/test_indexing.py

@@ -168,3 +168,73 @@ def test_mosa2sc():
         mosa2sc(1)
     with raises(ValueError):
         mosa2sc('1')
+
+
+def test_sc2leftdistant():
+    """Test that we return the left distant SC index."""
+
+    assert sc2leftdistant('1') == '2'
+    assert sc2leftdistant('2') == '3'
+    assert sc2leftdistant('3') == '1'
+
+    assert sc2leftdistant(1) == '2'
+    assert sc2leftdistant(2) == '3'
+    assert sc2leftdistant(3) == '1'
+
+    with raises(ValueError):
+        sc2leftdistant(0)
+    with raises(ValueError):
+        sc2leftdistant(4)
+    with raises(ValueError):
+        sc2leftdistant('12')
+
+
+def test_sc2rightdistant():
+    """Test that we return the right distant SC index."""
+
+    assert sc2rightdistant('1') == '3'
+    assert sc2rightdistant('2') == '1'
+    assert sc2rightdistant('3') == '2'
+
+    assert sc2rightdistant(1) == '3'
+    assert sc2rightdistant(2) == '1'
+    assert sc2rightdistant(3) == '2'
+
+    with raises(ValueError):
+        sc2rightdistant(0)
+    with raises(ValueError):
+        sc2rightdistant(4)
+    with raises(ValueError):
+        sc2rightdistant('12')
+
+
+def test_sc2leftmosa():
+    """Test that we return left MOSA index."""
+
+    assert sc2leftmosa('1') == '12'
+    assert sc2leftmosa('2') == '23'
+    assert sc2leftmosa('3') == '31'
+
+    assert sc2leftmosa(1) == '12'
+    assert sc2leftmosa(2) == '23'
+    assert sc2leftmosa(3) == '31'
+
+
+def test_sc2rightmosa():
+    """Test that we return right MOSA index."""
+
+    assert sc2rightmosa('1') == '13'
+    assert sc2rightmosa('2') == '21'
+    assert sc2rightmosa('3') == '32'
+
+    assert sc2rightmosa(1) == '13'
+    assert sc2rightmosa(2) == '21'
+    assert sc2rightmosa(3) == '32'
+
+
+def test_sc2bothmosas():
+    """Test that we can broadcast a SC array to a MOSA array."""
+
+    sc_array = np.array([1, 2, 3])
+    mosa_array = np.array([1, 2, 3, 1, 3, 2])
+    assert np.all(sc2bothmosas(sc_array) == mosa_array)