function reconstruct_signal_gra

diffpy/snmf/subroutines.py

@@ -206,6 +206,32 @@ def reconstruct_signal(components, signal_idx):
         reconstruction += stretched_and_weighted
     return reconstruction
 
+def reconstruct_signal_gra(components, signal_idx):
+    """Reconstruts a specific signal's gradient from its weighted and stretched components.
+
+    Calculates the linear combination of stretched components' gradients where each is the strethced component's
+    gradient multiplied by its weight factor.
+
+    Parameters
+    ----------
+    components: tuple of Componentsignal objects
+      The tuple containing the ComponentSignal objects
+    signal_idx: int
+      The index of the specified 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.
+    """
+    signal_length = len(components[0].grid)
+    reconstruction = np.zeros(signal_length)
+    for component in components:
+        stretched = component.apply_stretch(signal_idx)[1]
+        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):
     """Generates the initial guesses for the weight, stretching, and component matrices

diffpy/snmf/tests/test_subroutines.py

@@ -2,8 +2,8 @@
 import numpy as np
 from diffpy.snmf.containers import ComponentSignal
 from diffpy.snmf.subroutines import objective_function, get_stretched_component, reconstruct_data, get_residual_matrix, \
-    update_weights_matrix, initialize_arrays, lift_data, initialize_components, construct_stretching_matrix, \
-    construct_component_matrix, construct_weight_matrix, update_weights, reconstruct_signal
+    update_weights_matrix, lift_data, initialize_components, construct_stretching_matrix, \
+    construct_component_matrix, construct_weight_matrix, update_weights, reconstruct_signal, reconstruct_signal_gra
 
 to = [
     ([[[1, 2], [3, 4]], [[5, 6], [7, 8]], 1e11, [[1, 2], [3, 4]], [[1, 2], [3, 4]], 1], 2.574e14),
@@ -266,3 +266,17 @@ def test_update_weights(tuw):
 def test_reconstruct_signal(trs):
     actual = reconstruct_signal(trs[0], trs[1])
     assert len(actual) == len(trs[0][0].grid)
+
+trsg = 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('trsg', trsg)
+def test_reconstruct_signal_gra(trsg):
+    actual = reconstruct_signal_gra(trsg[0], trsg[1])
+    assert len(actual) == len(trsg[0][0].grid)