DOC: add pad to the API documentation

DOC: enable intersphinx extension to allow linking to numpy docs

DOC: consistently link Modes documentation from docstrings

Author: grlee77

doc/source/conf.py

@@ -36,6 +36,7 @@
 extensions = ['sphinx.ext.doctest', 'sphinx.ext.autodoc', 'sphinx.ext.todo',
               'sphinx.ext.extlinks', 'sphinx.ext.mathjax',
               'sphinx.ext.autosummary', 'numpydoc',
+              'sphinx.ext.intersphinx',
               'matplotlib.sphinxext.plot_directive']
 
 # Add any paths that contain templates here, relative to this directory.
@@ -224,3 +225,9 @@
 plot_formats = [('png', 96), 'pdf']
 plot_html_show_formats = False
 plot_html_show_source_link = False
+
+# -- Options for intersphinx extension ---------------------------------------
+
+# Intersphinx to get Numpy and other targets
+intersphinx_mapping = {
+    'numpy': ('https://docs.scipy.org/doc/numpy/', None)}

doc/source/ref/signal-extension-modes.rst

@@ -136,3 +136,15 @@ periodization      per           N/A
 antisymmetric      asym, asymh   N/A
 antireflect        asymw         reflect, reflect_type='odd'
 ================== ============= ===========================
+
+Padding using PyWavelets Signal Extension Modes - ``pad``
+---------------------------------------------------------
+
+.. autofunction:: pad
+
+Pywavelets provides a function, :func:`pad`, that operate like
+:func:`numpy.pad`, but supporting the PyWavelets signal extension modes
+discussed above. For efficiency, the DWT routines in PyWavelets do not
+expclitly create padded signals using this function. It can be used to manually
+prepad signals to reduce boundary effects in functions such as :func:`cwt` and
+:func:`swt` that do not currently support all of these signal extension modes.

pywt/_dwt.py

@@ -135,7 +135,6 @@ def dwt(data, wavelet, mode='symmetric', axis=-1):
         Axis over which to compute the DWT. If not given, the
         last axis is used.
 
-
     Returns
     -------
     (cA, cD) : tuple
@@ -211,7 +210,6 @@ def idwt(cA, cD, wavelet, mode='symmetric', axis=-1):
         Axis over which to compute the inverse DWT. If not given, the
         last axis is used.
 
-
     Returns
     -------
     rec: array_like
@@ -406,7 +404,7 @@ def upcoef(part, coeffs, wavelet, level=1, take=0):
 def pad(x, pad_widths, mode):
     """Extend a 1D signal using a given boundary mode.
 
-    This function operates like `numpy.pad` but supports all signal extension
+    This function operates like ``numpy.pad`` but supports all signal extension
     modes that can be used by PyWavelets discrete wavelet transforms.
 
     Parameters
@@ -420,7 +418,7 @@ def pad(x, pad_widths, mode):
         axis. (pad,) or int is a shortcut for before = after = pad width for
         all axes.
     mode : str, optional
-        Signal extension mode, see Modes.
+        Signal extension mode, see :ref:`Modes <ref-modes>`.
 
     Returns
     -------
@@ -430,9 +428,9 @@ def pad(x, pad_widths, mode):
 
     Notes
     -----
-    The performance of padding in dimensions > 1 will be substantially slower
-    for modes `smooth` and `antisymmetric` as these modes are not supported in
-    an efficient manner by the underlying `numpy.pad` function.
+    The performance of padding in dimensions > 1 may be substantially slower
+    for modes ``smooth`` and ``antisymmetric`` as these modes are not supported
+    efficiently by the underlying ``numpy.pad`` function.
     """
     x = np.asanyarray(x)