added function contents

Author: aajayi-21

diffpy/snmf/subroutines.py

@@ -187,15 +187,21 @@ def reconstruct_signal(components, signal_idx):
     components: tuple of ComponentSignal objects
       The tuple containing the ComponentSignal objects
     signal_idx: int
-     The index of the specific signal to be reconstructed
+     The index of the specific signal in the input data to be reconstructed
 
     Returns
     -------
     1d array like
       The reconstruction of a signal from calculated weights, stretching factors, and iq values.
 
     """
-    pass
+    signal_length = len(components[0].grid)
+    reconstruction = np.zeros(signal_length)
+    for component in components:
+        stretched = component.apply_stretch(signal_idx)[0]
+        stretched_and_weighted = component.apply_weight(signal_idx, stretched)
+        reconstruction += stretched_and_weighted
+    return reconstruction
 
 
 def initialize_arrays(number_of_components, number_of_moments, signal_length):

diffpy/snmf/tests/test_subroutines.py

@@ -252,7 +252,17 @@ def test_construct_weight_matrix(tcwm):
 def test_update_weights(tuw):
     actual = update_weights(tuw[0], tuw[1], tuw[2])
     assert np.shape(actual) == (len(tuw[0]), len(tuw[0][0].weights))
-trs = []
+
+trs = [([ComponentSignal([0, .25, .5, .75, 1], 2, 0), ComponentSignal([0, .25, .5, .75, 1], 2, 1),
+         ComponentSignal([0, .25, .5, .75, 1], 2, 2)], 1),
+       ([ComponentSignal([0, .25, .5, .75, 1], 2, 0), ComponentSignal([0, .25, .5, .75, 1], 2, 1),
+         ComponentSignal([0, .25, .5, .75, 1], 2, 2)], 0),
+       ([ComponentSignal([0, .25, .5, .75, 1], 3, 0), ComponentSignal([0, .25, .5, .75, 1], 3, 1),
+         ComponentSignal([0, .25, .5, .75, 1], 3, 2)], 2),
+       # ([ComponentSignal([0, .25, .5, .75, 1], 2, 0), ComponentSignal([0, .25, .5, .75, 1], 2, 1),
+        # ComponentSignal([0, .25, .5, .75, 1], 2, 2)], -1),
+]
 @pytest.mark.parametrize('trs',trs)
 def test_reconstruct_signal(trs):
-    assert False
+    actual = reconstruct_signal(trs[0], trs[1])
+    assert len(actual) == len(trs[0][0].grid)