Add possibility to turn off flexibility

src/library/correlated_fields_simple.py

@@ -52,40 +52,45 @@ class SimpleCorrelatedField(Operator):
             if len(kk) != 2:
                 raise TypeError
         for kk in [flexibility, asperity]:
-            if kk is None or len(kk) != 2:
+            if not (kk is None or len(kk) == 2):
                 raise TypeError
         if flexibility is None and asperity is not None:
             raise ValueError
         fluct = LognormalTransform(*fluctuations, prefix + 'fluctuations', 0)
-        flex = LognormalTransform(*flexibility, prefix + 'flexibility', 0)
-        asp = LognormalTransform(*asperity, prefix + 'asperity', 0)
         avgsl = NormalTransform(*loglogavgslope, prefix + 'loglogavgslope', 0)
         zm = LognormalTransform(*offset_std, prefix + 'zeromode', 0)
 
         pspace = PowerSpace(harmonic_partner)
         twolog = _TwoLogIntegrations(pspace)
+        expander = ContractionOperator(twolog.domain, 0).adjoint
+        ps_expander = ContractionOperator(pspace, 0).adjoint
+        vslope = makeOp(makeField(pspace, _relative_log_k_lengths(pspace)))
+        slope = vslope @ ps_expander @ avgsl
+        a = slope
+
+        if flexibility is not None:
+            flex = LognormalTransform(*flexibility, prefix + 'flexibility', 0)
             dom = twolog.domain[0]
             vflex = np.zeros(dom.shape)
-        vasp = np.zeros(dom.shape)
-        shift = np.ones(dom.shape)
             vflex[0] = vflex[1] = np.sqrt(_log_vol(pspace))
-        vasp[0] = 1
-        shift[0] = _log_vol(pspace)**2/12.
             vflex = makeOp(makeField(dom, vflex))
-        vasp = makeOp(makeField(dom, vasp))
-        shift = makeField(dom, shift)
-        vslope = makeOp(makeField(pspace, _relative_log_k_lengths(pspace)))
-
-        expander = ContractionOperator(twolog.domain, 0).adjoint
-        ps_expander = ContractionOperator(pspace, 0).adjoint
-        slope = vslope @ ps_expander @ avgsl
             sig_flex = vflex @ expander @ flex
-        sig_asp = vasp @ expander @ asp
             xi = ducktape(dom, None, prefix + 'spectrum')
-        smooth = xi*sig_flex*(Adder(shift) @ sig_asp).ptw("sqrt")
-        smooth = _SlopeRemover(pspace, 0) @ twolog @ smooth
-        a = _Normalization(pspace, 0) @ (slope + smooth)
 
+            if asperity is None:
+                raise NotImplementedError
+            asp = LognormalTransform(*asperity, prefix + 'asperity', 0)
+            vasp = np.zeros(dom.shape)
+            vasp[0] = 1
+            vasp = makeOp(makeField(dom, vasp))
+            sig_asp = vasp @ expander @ asp
+            shift = np.ones(dom.shape)
+            shift[0] = _log_vol(pspace)**2/12.
+            shift = makeField(dom, shift)
+            asp = (Adder(shift) @ sig_asp).ptw("sqrt")
+
+            a = a + _SlopeRemover(pspace, 0) @ twolog @ (xi*sig_flex*asp)
+        a = _Normalization(pspace, 0) @ a
         maskzm = np.ones(pspace.shape)
         maskzm[0] = 0
         maskzm = makeOp(makeField(pspace, maskzm))

test/test_operators/test_correlated_fields.py

@@ -171,3 +171,27 @@ def test_complicated_vs_simple(seed, domain):
         op0 = scf.amplitude
         assert_(op0.domain is op1.domain)
         ift.extra.assert_allclose(op0.force(inp), op1.force(inp))
+
+
+@pmp('asperity', [None, (_posrand(), _posrand())])
+@pmp('flexibility', [None, (_posrand(), _posrand())])
+def test_simple_without_asp_fluct(asperity, flexibility):
+    domain = ift.RGSpace((4, 4), (0.123, 0.4))
+    offset_mean = _rand()
+    offset_std = _posrand(), _posrand()
+    fluctuations = _posrand(), _posrand()
+    loglogavgslope = _posrand(), _posrand()
+    prefix = 'foobar'
+    hspace = domain.get_default_codomain()
+    args = (domain, offset_mean, offset_std, fluctuations, flexibility,
+            asperity, loglogavgslope, prefix, hspace)
+    if asperity is not None and flexibility is None:
+        with pytest.raises(ValueError):
+            scf = ift.SimpleCorrelatedField(*args)
+    elif asperity is None and flexibility is not None:
+        with pytest.raises(NotImplementedError):
+            scf = ift.SimpleCorrelatedField(*args)
+    else:
+        scf = ift.SimpleCorrelatedField(*args)
+        inp = ift.from_random(scf.domain)
+        ift.extra.check_operator(scf, inp, ntries=10)