fixed typo

Author: hugofluhr

nigsp/operations/metrics.py

@@ -248,7 +248,7 @@ def _fc(timeseries, mean=False):
 
 @due.dcite(references.SHUMAN_2013)
 def smoothness(laplacian, signal):
-    """Compute the smoothness of a signal over the graph corresponding to given laplacian.
+    """Compute the smoothness of a signal (as defined in [1]) over the graph corresponding to given Laplacian.
 
     Parameters
     ----------
@@ -270,7 +270,31 @@ def smoothness(laplacian, signal):
         Processing Magazine, vol. 30, no. 3, pp. 83-98, May 2013
     """
     LGR.info("Compute signal smoothness.")
-    return np.dot(signal.T, np.dot(laplacian, signal))
+
+    # Checking shape of signal
+    if signal.ndim == 1:
+        LGR.warning(
+            "2D array required, but signal is a vector. Adding empty dimension."
+        )
+        signal = np.expand_dims(signal, -1)
+    elif signal.ndim > 2:
+        raise ValueError("Signal should be a 2D array.")
+
+    # Checking if laplacian is square
+    if laplacian.shape[0] != laplacian.shape[1]:
+        raise ValueError("Laplacian should be a square matrix.")
+
+    # Checking that the dimensions of signal and laplacian are compatible
+    if signal.shape[0] != laplacian.shape[0]:
+        if signal.shape[1] == laplacian.shape[0]:
+            LGR.warning(
+                "It seems that the signal needs to be transposed to the correct shape."
+            )
+            signal = np.swapaxes(signal, 0, 1)
+        else:
+            raise ValueError("The dimensions of the signal and Laplacian don't match.")
+
+    return np.matmul(signal.T, np.matmul(laplacian, signal))
 
 
 """

nigsp/tests/test_metrics.py

@@ -73,13 +73,13 @@ def test_gsdi():
 
 
 def test_smoothness():
-    signal = rand(10, 1)
+    signal = rand(10, 2)
     laplacian = rand(10, 10)
 
     expected_smoothness = np.dot(signal.T, np.dot(laplacian, signal))
     computed_smoothness = metrics.smoothness(laplacian, signal)
 
-    assert np.isclose(expected_smoothness, computed_smoothness, rtol=1e-10)
+    assert (expected_smoothness == computed_smoothness).all()
 
 
 # ### Break tests
@@ -134,3 +134,29 @@ def test_functional_connectivity():
 
     for k in fcd.keys():
         assert (fcd[k] == np.corrcoef(tsd[k])).all()
+
+
+def test_break_smoothness():
+    # shape of signal
+    signal = rand(3, 3, 3)
+    laplacian = rand(3, 3)
+
+    with raises(ValueError) as errorinfo:
+        metrics.smoothness(laplacian, signal)
+    assert "should be a 2D" in str(errorinfo.value)
+
+    # shape of laplacian
+    signal = rand(10, 2)
+    laplacian = rand(10, 9)
+
+    with raises(ValueError) as errorinfo:
+        metrics.smoothness(laplacian, signal)
+    assert "a square matrix" in str(errorinfo.value)
+
+    # shape mismatch
+    signal = rand(10, 2)
+    laplacian = rand(9, 9)
+
+    with raises(ValueError) as errorinfo:
+        metrics.smoothness(laplacian, signal)
+    assert "don't match" in str(errorinfo.value)