Merge pull request #45 from aajayi-21/construct_weights

function construct_weight_matrix

Author: sbillinge

diffpy/snmf/subroutines.py

@@ -111,6 +111,34 @@ def construct_component_matrix(components):
     return component_matrix
 
 
+def construct_weight_matrix(components):
+    """Constructs the weights matrix
+
+    Constructs a Ķ x M matrix where K is the number of components and M is the
+    number of signals. Each element is the stretching factor for a specific
+    weights for a specific signal from the data input.
+
+    Parameters
+    ----------
+    components: tuple of ComponentSignal objects
+      The tuple containing the component signals.
+
+    Returns
+    -------
+    2d array like
+      The 2d array containing the weightings for each component for each signal.
+    """
+    number_of_components = len(components)
+    number_of_signals = len(components[0].weights)
+    if number_of_components == 0:
+        raise ValueError(f"Number of components = {number_of_components}. Number of components must be >= 1")
+    if number_of_signals == 0:
+        raise ValueError(f"Number of signals = {number_of_signals}. Number_of_signals must be >= 1.")
+    weights_matrix = np.zeros((number_of_components,number_of_signals))
+    for i, component in enumerate(components):
+        weights_matrix[i] = component.weights
+    return weights_matrix
+
 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

@@ -2,7 +2,7 @@
 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
+    update_weights_matrix, initialize_arrays, lift_data, initialize_components, construct_stretching_matrix, construct_component_matrix, construct_weight_matrix
 
 to = [
     ([[[1, 2], [3, 4]], [[5, 6], [7, 8]], 1e11, [[1, 2], [3, 4]], [[1, 2], [3, 4]], 1], 2.574e14),
@@ -206,3 +206,22 @@ def test_construct_component_matrix(tccm):
     actual = construct_component_matrix(tccm)
     for component in tccm:
         np.testing.assert_allclose(actual[component.id], component.iq)
+
+tcwm = [
+        ([ComponentSignal([0,.25,.5,.75,1],20,0)]),
+        # ([ComponentSignal([0,.25,.5,.75,1],0,0)]), # 0 signal length. Failure expected
+        ([ComponentSignal([0,.25,.5,.75,1],20,0),ComponentSignal([0,.25,.5,.75,1],20,1),ComponentSignal([0,.25,.5,.75,1],20,2)]),
+        ([ComponentSignal([0, .25, .5, .75, 1], 20, 0), ComponentSignal([0, .25, .5, .75, 1], 20, 1),
+          ComponentSignal([0, .25, .5, .75, 1], 20, 2)]),
+        ([ComponentSignal([0, .25, .5, .75, 1], 20, 0), ComponentSignal([0, .25, .5, 2.75, 1], 20, 1),
+          ComponentSignal([0, .25, .5, .75, 1], 20, 2)]),
+        ([ComponentSignal([.25], 20, 0), ComponentSignal([.25], 20, 1), ComponentSignal([.25], 20, 2)]),
+        ([ComponentSignal([0, .25, .5, .75, 1], 20, 0), ComponentSignal([0, .25, .5, .75, 1], 20, 1)]),
+        #(ComponentSignal([], 20, 0)), # Expected to fail
+        #([]), #Expected to fail
+]
+@pytest.mark.parametrize('tcwm',tcwm)
+def test_construct_weight_matrix(tcwm):
+    actual = construct_weight_matrix(tcwm)
+    for component in tcwm:
+        np.testing.assert_allclose(actual[component.id], component.weights)