updated format and testing for fdc

Author: prmiles

pyfod/fdc.py

@@ -2,9 +2,9 @@
 
 import sys
 import numpy as np
-from scipy.special import gamma as sc_gamma
 import sympy as sp
-from GaussLegendreRiemannSum import GaussLegendreRiemannSum
+from scipy.special import gamma as sc_gamma
+from pyfod.GaussLegendreRiemannSum import GaussLegendreRiemannSum
 from pyfod.GaussLegendre import GaussLegendre
 from pyfod.GaussLaguerre import GaussLaguerre
 from pyfod.RiemannSum import RiemannSum
@@ -18,13 +18,13 @@ def fdc(f, start, finish, dt=1e-4, alpha=0.0, quadrature='GLegRS', **kwargs):
     Q2 = quad(start=start, finish=finish-dt, alpha=alpha, **kwargs)
     I2 = Q2.integrate(f=f)
 
-    if quadrature == 'GLag':
+    if quadrature.lower() == 'glag':
         extend_precision = True
     else:
         extend_precision = False
 
     if extend_precision is True:
-        fd = (I1-I2)/(dt*sp.gamma(1-alpha))
+        fd = float((I1-I2)/(dt*sp.gamma(1-alpha)))
     else:
         fd = (I1-I2)/(dt*sc_gamma(1 - alpha))
     # assemble output
@@ -33,13 +33,13 @@ def fdc(f, start, finish, dt=1e-4, alpha=0.0, quadrature='GLegRS', **kwargs):
 
 def select_quadrature_method(quadrature):
     methods = dict(
-            GLegRS=GaussLegendreRiemannSum,
-            GLag=GaussLaguerre,
-            GLeg=GaussLegendre,
-            RS=RiemannSum
+            glegrs=GaussLegendreRiemannSum,
+            glag=GaussLaguerre,
+            gleg=GaussLegendre,
+            rs=RiemannSum
             )
     try:
-        quad = methods[quadrature]
+        quad = methods[quadrature.lower()]
         return quad
     except KeyError:
         print('Invalid quadrature method specified: {}'.format(quadrature))
@@ -57,6 +57,8 @@ def fcos(t):
     def fexp(t):
         return np.exp(2*t)
 
+    def fspexp(t):
+        return sp.exp(2*t)
 
     start = 0.0
     finish = 1.0
@@ -74,3 +76,20 @@ def fexp(t):
     alpha = 0.9
     out = fdc(f=fexp, alpha=alpha, start=start, finish=finish, dt=dt, NRS=NRS)
     print('D^{}[exp(2t)] = {} ({})'.format(alpha, out['fd'], 13.8153))
+
+    # Test Extended Precision - Gauss Laguerre Quadrature
+    # Test alpha = 0.0
+    alpha = 0.0
+    out = fdc(f=fspexp, alpha=alpha, start=start, finish=finish, dt=dt,
+              quadrature='glag')
+    print('D^{}[exp(2t)] = {} ({})'.format(alpha, out['fd'], 7.38906))
+    # Test alpha = 0.1
+    alpha = 0.1
+    out = fdc(f=fspexp, alpha=alpha, start=start, finish=finish, dt=dt,
+              quadrature='glag')
+    print('D^{}[exp(2t)] = {} ({})'.format(alpha, out['fd'], 7.95224))
+    # Test alpha = 0.9
+    alpha = 0.9
+    out = fdc(f=fspexp, alpha=alpha, start=start, finish=finish, dt=dt,
+              quadrature='glag', N=32, n_digits=60)
+    print('D^{}[exp(2t)] = {} ({})'.format(alpha, out['fd'], 13.8153))

test/test_fdc.py

@@ -0,0 +1,46 @@
+# -*- coding: utf-8 -*-
+import unittest
+from pyfod import fdc
+import numpy as np
+import sympy as sp
+
+
+def fexp(t):
+    return np.exp(2*t)
+
+
+def fsp(t):
+    return sp.exp(2*t)
+
+
+# --------------------------
+class SelectQuadratureMethodTesting(unittest.TestCase):
+
+    def test_selection(self):
+        with self.assertRaises(SystemExit):
+            fdc.select_quadrature_method(quadrature='hello')
+
+
+# --------------------------
+class FDC(unittest.TestCase):
+
+    def check_contents(self, out):
+        keys = ['fd', 'I1', 'I2', 'Q1', 'Q2']
+        for key in keys:
+            self.assertTrue(key in out,
+                            msg=str('{} not in output'.format(key)))
+            self.assertTrue(isinstance(out['fd'], float),
+                            msg='Expect float')
+
+    def test_fdc(self):
+        start = 0.0
+        finish = 1.0
+        NRS = 10
+        # Test alpha = 0.0
+        alpha = 0.0
+        out = fdc.fdc(f=fexp, alpha=alpha, start=start,
+                      finish=finish, NRS=NRS)
+        self.check_contents(out)
+        out = fdc.fdc(f=fsp, alpha=alpha, start=start,
+                      finish=finish, quadrature='glag')
+        self.check_contents(out)