diff -Naur bumps-0.7.11/bumps/numdifftools/core.py bumps-0.7.11_patched/bumps/numdifftools/core.py
--- bumps-0.7.11/bumps/numdifftools/core.py	2019-07-22 11:00:07.663853366 +0200
+++ bumps-0.7.11_patched/bumps/numdifftools/core.py	2018-09-24 21:06:44.000000000 +0200
@@ -23,7 +23,7 @@
 import numpy as np
 from collections import namedtuple
 from numpy import linalg
-from scipy import misc
+from scipy import misc, special
 import warnings
 
 # 2016-04-19 PAK use relative imports
@@ -631,9 +631,9 @@
     def _vstack(self, sequence, steps):
         # sequence = np.atleast_2d(sequence)
         original_shape = np.shape(sequence[0])
-        f_del = np.vstack(list(np.ravel(r)) for r in sequence)
-        h = np.vstack(list(np.ravel(np.ones(original_shape)*step))
-                      for step in steps)
+        f_del = np.vstack([list(np.ravel(r)) for r in sequence])
+        h = np.vstack([list(np.ravel(np.ones(original_shape)*step))
+                      for step in steps])
         if f_del.size != h.size:
             raise ValueError('fun did not return data of correct size ' +
                              '(it must be vectorized)')
@@ -683,6 +683,7 @@
     >>> np.allclose(fd(1), 2.71828183)
     True
 
+    >>> fd = nd.Derivative(np.exp)
     >>> d2 = fd([1, 2])
     >>> np.allclose(d2, [ 2.71828183,  7.3890561 ])
     True
@@ -781,7 +780,7 @@
         inv_sr = 1.0 / step_ratio
         offset = [1, 1, 2, 2, 4, 1, 3][parity]
         c0 = [1.0, 1.0, 1.0, 2.0, 24.0, 1.0, 6.0][parity]
-        c = c0/misc.factorial(np.arange(offset, step * nterms + offset, step))
+        c = c0/special.factorial(np.arange(offset, step * nterms + offset, step))
         [i, j] = np.ogrid[0:nterms, 0:nterms]
         return np.atleast_2d(c[j] * inv_sr ** (i * (step * j + offset)))
 
diff -Naur bumps-0.7.11/doc/conf.py bumps-0.7.11_patched/doc/conf.py
--- bumps-0.7.11/doc/conf.py	2019-07-22 11:01:21.761248474 +0200
+++ bumps-0.7.11_patched/doc/conf.py	2018-09-24 21:06:44.000000000 +0200
@@ -51,8 +51,8 @@
               #'sphinx.ext.jsmath',
               'sphinx.ext.mathjax',
               #'only_directives',
+              'matplotlib.sphinxext.mathmpl',
+              #'matplotlib.sphinxext.only_directives',
-              #'matplotlib.sphinxext.mathmpl',
-              'matplotlib.sphinxext.only_directives',
               'matplotlib.sphinxext.plot_directive',
               #'inheritance_diagram',
               'dollarmath',
diff -Naur bumps-0.7.11/doc/Makefile bumps-0.7.11_patched/doc/Makefile
--- bumps-0.7.11/doc/Makefile	2019-07-22 11:00:58.871022945 +0200
+++ bumps-0.7.11_patched/doc/Makefile	2018-09-24 21:06:44.000000000 +0200
@@ -4,7 +4,7 @@
 # You can set these variables from the command line.
 PYTHON        ?= python
 SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
-SPHINXBUILD   = $(PYTHON) -m sphinx.__init__
 #sphinx-build
 PAPER         =
 BUILDDIR      = _build
@@ -12,7 +12,7 @@
 # Internal variables.
 PAPEROPT_a4     = -D latex_paper_size=a4
 PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -a $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
-ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
 
 .PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp \
         devhelp epub latex pdf text man changes linkcheck doctest