fix: typo in EMD_matlab

PyEMD/EMD_matlab.py

@@ -84,7 +84,9 @@ def extractMaxMinSpline(self, T, S):
             return [-1] * 4
 
         # Extrapolation of signal (ober boundaries)
-        maxExtrema, minExtrema = self.preparePoints(S, T, maxPos, maxVal, minPos, minVal)
+        maxExtrema, minExtrema = self.preparePoints(
+            S, T, maxPos, maxVal, minPos, minVal
+        )
 
         _, maxSpline = self.splinePoints(T, maxExtrema, self.splineKind)
         _, minSpline = self.splinePoints(T, minExtrema, self.splineKind)
@@ -218,8 +220,12 @@ def preparePoints(self, S, T, maxPos, maxVal, minPos, minVal):
         minExtrema = np.array([tmin, zmin], dtype=self.DTYPE)
 
         # Make double sure, that each extremum is significant
-        maxExtrema = np.delete(maxExtrema, np.where(maxExtrema[0, 1:] == maxExtrema[0, :-1]), axis=1)
-        minExtrema = np.delete(minExtrema, np.where(minExtrema[0, 1:] == minExtrema[0, :-1]), axis=1)
+        maxExtrema = np.delete(
+            maxExtrema, np.where(maxExtrema[0, 1:] == maxExtrema[0, :-1]), axis=1
+        )
+        minExtrema = np.delete(
+            minExtrema, np.where(minExtrema[0, 1:] == minExtrema[0, :-1]), axis=1
+        )
 
         return maxExtrema, minExtrema
 
@@ -251,7 +257,9 @@ def splinePoints(self, T, extrema, splineKind):
 
         elif kind == "cubic":
             if extrema.shape[1] > 3:
-                return t, interp1d(extrema[0], extrema[1], kind=kind)(t).astype(self.DTYPE)
+                return t, interp1d(extrema[0], extrema[1], kind=kind)(t).astype(
+                    self.DTYPE
+                )
             else:
                 return self.cubicSpline_3points(T, extrema)
 
@@ -435,8 +443,18 @@ def emd(self, S, T=None, maxImf=None):
         The decomposition is limited to maxImf imf. No limitation as default.
         Returns IMF functions in dic format. IMF = {0:imf0, 1:imf1...}.
 
+        *Note*: First argument `self` should be an instance of EMD class.
+        It should be resolved in future versions.
+
+        For example:
+        ```
+        emd = EMD()
+        emd.emd(emd, S, T, maxImf)
+        ```
+
         Input:
         ---------
+            self: Instance of EMD class.
             S: Signal.
             T: Positions of signal. If none passed numpy arange is created.
             maxImf: IMF number to which decomposition should be performed.
@@ -457,7 +475,7 @@ def emd(self, S, T=None, maxImf=None):
             maxImf = -1
 
         # Make sure same types are dealt
-        S, T = unify_type(S, T)
+        S, T = unify_types(S, T)
         self.DTYPE = S.dtype
 
         Res = S.astype(self.DTYPE)
@@ -479,7 +497,7 @@ def emd(self, S, T=None, maxImf=None):
 
         if S.shape != T.shape:
             info = "Time array should be the same size as signal."
-            raise Exception(info)
+            raise ValueError(info)
 
         # Create arrays
         IMF = {}  # Dic for imfs signals

PyEMD/__init__.py

@@ -1,6 +1,6 @@
 import logging
 
-__version__ = "1.6.3"
+__version__ = "1.6.4"
 logger = logging.getLogger("pyemd")
 
 from PyEMD.CEEMDAN import CEEMDAN  # noqa

PyEMD/tests/test_emd_matlab.py

@@ -0,0 +1,49 @@
+import unittest
+
+import numpy as np
+
+from PyEMD.EMD_matlab import EMD
+
+
+class EMDMatlabTest(unittest.TestCase):
+    @staticmethod
+    def test_default_call_EMD():
+        T = np.arange(0, 1, 0.01)
+        S = np.cos(2 * T * 2 * np.pi)
+        max_imf = 2
+
+        emd = EMD()
+        emd.emd(emd, S, T, max_imf)
+
+    def test_different_length_input(self):
+        T = np.arange(20)
+        S = np.random.random(len(T) + 7)
+
+        emd = EMD()
+        with self.assertRaises(ValueError):
+            emd.emd(emd, S, T)
+
+    def test_trend(self):
+        """
+        Input is trend. Expeting no shifting process.
+        """
+        emd = EMD()
+
+        T = np.arange(0, 1, 0.01)
+        S = np.cos(2 * T * 2 * np.pi)
+
+        # Input - linear function f(t) = 2*t
+        output = emd.emd(emd, S, T)
+        self.assertEqual(len(output), 4, "Expecting 4 outputs - IMF, EXT, ITER, imfNo")
+
+        IMF, EXT, ITER, imfNo = output
+        self.assertEqual(len(IMF), 2, "Expecting single IMF + residue")
+        self.assertEqual(len(IMF[0]), len(S), "Expecting single IMF")
+        self.assertTrue(np.allclose(S, IMF[0]))
+        self.assertLessEqual(ITER[0], 5, "Expecting 5 iterations at most")
+        self.assertEqual(imfNo, 2, "Expecting 1 IMF")
+        self.assertEqual(EXT[0], 3, "Expecting single EXT")
+
+
+if __name__ == "__main__":
+    unittest.main()