DOC: add pad to the API documentation

DOC: enable intersphinx extension to allow linking to numpy docs

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.