src/nmreval/models/bds.py

@@ -1,5 +1,6 @@
 import numpy as np
 
+from . import PowerLaw
 from ..distributions import Debye, ColeCole, ColeDavidson, KWW, HavriliakNegami
 from ..utils.constants import epsilon0
 
@@ -232,8 +233,8 @@ class DCCondBDS:
 
 
 class DerivativeHavriliakNegami:
-    name = 'Derivative HN'
-    type = 'Dielectric Spectroscopy'
+    name = 'Havriliak-Negami (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\alpha', r'\gamma']
     choices = [
         ('x axis', 'xaxis', {'Frequency': 'freq', 'Omega': 'omega'})
@@ -254,8 +255,8 @@ class DerivativeHavriliakNegami:
 
 
 class DerivativeColeCole:
-    name = 'Derivative CC'
-    type = 'Dielectric Spectroscopy'
+    name = 'Cole-Cole (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\alpha']
     bounds = [(0, None), (0, None), (0, 1)]
     choices = [
@@ -276,8 +277,8 @@ class DerivativeColeCole:
 
 
 class DerivativeColeDavidson:
-    name = 'Derivative CD'
-    type = 'Dielectric Spectroscopy'
+    name = 'Cole-Davidson (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\gamma']
     bounds = [(0, None), (0, None), (0, 1)]
     choices = [
@@ -295,8 +296,8 @@ class DerivativeColeDavidson:
 
 
 class _DerivativeHNWithHF:
-    name = 'Derivative (HN + HF wing)'
-    type = 'Dielectric Spectroscopy'
+    name = 'HN + HF wing (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\alpha', r'\gamma', r'\tau_{c}', r'\delta']
     bounds = [(0, None), (0, None), (0, 1), (0, 1), (0, None), (0, 1)]
     choices = [
@@ -325,8 +326,8 @@ class _DerivativeHNWithHF:
 
 
 class DerivativeCCWithHF:
-    name = 'Derivative (CC + HF wing)'
-    type = 'Dielectric Spectroscopy'
+    name = 'CC + HF wing (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\alpha', r'\tau_{c}', r'\delta']
     bounds = [(0, None), (0, None), (0, 1), (0, None), (0, 1)]
     choices = [
@@ -339,8 +340,8 @@ class DerivativeCCWithHF:
 
 
 class DerivativeCDWithHF:
-    name = 'Derivative (CD + HF wing)'
-    type = 'Dielectric Spectroscopy'
+    name = 'CD + HF wing (der.)'
+    type = 'Dielectric Spectroscopy (derivative)'
     params = [r'\Delta\epsilon', r'\tau', r'\gamma', r'\tau_{c}', r'\delta']
     bounds = [(0, None), (0, None), (0, 1), (0, None), (0, 1)]
     choices = [
@@ -352,6 +353,22 @@ class DerivativeCDWithHF:
         return _DerivativeHNWithHF.func(x, deps, tau, 1, gamma, tauc, delta, xaxis=xaxis)
 
 
+class PowerLawBDSDer:
+    name = 'Power Law'
+    type = 'Dielectric Spectroscopy (derivative)'
+    equation = r'A * \omega^{n}'
+    params = ['A', 'n']
+    bounds = [(None, None), (None, None)]
+    choices = [
+        ('x axis', 'xaxis', {'Frequency': 'freq', 'Omega': 'omega'})
+    ]
+
+    @staticmethod
+    def func(x, a, n, xaxis: str = 'freq'):
+        _w = _convert_x_to_omega(x, xaxis=xaxis)
+        return a * _w ** n
+
+
 def _convert_x_to_omega(x, xaxis: str = 'freq'):
     if xaxis not in ['freq', 'omega']:
         raise ValueError(f'Argument `xaxis` is `freq` or `omega`, given is {xaxis!r}')