diff --git a/doc/install.rst b/doc/install.rst
index ead24fec0592bb39150389ea4d141b1b6d045f76..4243c782ab9e6aa4c60f5af95f646564f9559d6d 100644
--- a/doc/install.rst
+++ b/doc/install.rst
@@ -28,7 +28,10 @@ For developpers only:
 Scientific Python libraries
 ---------------------------
 
-* You need to have **libfftw3**, development version, installed. For debian based linux systems use ``$apt install libfftw3-dev``. For other systems, please read the documentation of `fftw <http://www.fftw.org/>`_.
+* You need to have **libfftw3**, development version, installed. 
+    * For debian based linux systems use: ``$apt install libfftw3-dev``.
+    * For MACOS X based systems, you may use: ``sudo port install fftw-3 fftw-3-single``.
+    * For other systems, please read the documentation of `fftw <http://www.fftw.org/>`_.
 * **ltfatpy** is using **numpy** >= 1.9, **scipy** >= 0.15 and **matplotlib** >= 1.4. For installing those packages read the instructions in:
 `here <http://www.scipy.org/install.html>`_.
 
diff --git a/ltfatpy/gabor/dgtreal.py b/ltfatpy/gabor/dgtreal.py
index 779e74e80afc955a0de4d02226e932856ffb7008..483c32b73112cccad851c63dfe53d8a3e96450f4 100644
--- a/ltfatpy/gabor/dgtreal.py
+++ b/ltfatpy/gabor/dgtreal.py
@@ -75,6 +75,7 @@ def dgtreal(f, g, a, M, L=None, pt='freqinv'):
     - Usage:
         | ``(c, Ls, g) = dgtreal(f, g, a, M)``
         | ``(c, Ls, g) = dgtreal(f, g, a, M, L)``
+        | ``(c, Ls, g) = dgtreal(f, g, a, M, L, pt)``
 
     - Input parameters:
 
diff --git a/ltfatpy/gabor/idgt.py b/ltfatpy/gabor/idgt.py
index c954f9e55d2338cc453c8199e8c7fd21d8bd5d64..aa302ef11355e18816cae1533807c51b799fa5bd 100644
--- a/ltfatpy/gabor/idgt.py
+++ b/ltfatpy/gabor/idgt.py
@@ -79,6 +79,7 @@ def idgt(coef, g, a, Ls=None, pt='freqinv'):
 
         | ``(f, g) = idgt(c, g, a)``
         | ``(f, g) = idgt(c, g, a, Ls)``
+        | ``(f, g) = idgt(c, g, a, Ls, pt)``
 
     - Input parameters:
 
@@ -86,6 +87,7 @@ def idgt(coef, g, a, Ls=None, pt='freqinv'):
     :param g: Window function
     :param int a: Length of time shift
     :param int Ls: Length of signal
+    :param str pt: 'freqinv' or 'timeinv'. Default is 'freqinv'.
     :type g: str, dict or numpy.ndarray
 
     - Output parameters:
diff --git a/ltfatpy/gabor/idgtreal.py b/ltfatpy/gabor/idgtreal.py
index 53d29e91e4d0ffe63a87fef33b7dc89e08915d0f..10762084e93611508a9946113f6fc0051c397a25 100644
--- a/ltfatpy/gabor/idgtreal.py
+++ b/ltfatpy/gabor/idgtreal.py
@@ -78,6 +78,7 @@ def idgtreal(coef, g, a, M, Ls=None, pt='freqinv'):
     - Usage:
         | ``(f, g) = idgtreal(c, g, a, M)``
         | ``(f, g) = idgtreal(c, g, a, M, Ls)``
+        | ``(f, g) = idgtreal(c, g, a, M, Ls, pt)``
 
     - Input parameters:
 
@@ -86,6 +87,7 @@ def idgtreal(coef, g, a, M, Ls=None, pt='freqinv'):
     :param int a: Length of time shift
     :param int M: Number of channels
     :param int Ls: Length of signal
+    :param str pt: 'freqinv' or 'timeinv'. Default is 'freqinv'.
     :type g: str, dict or numpy.ndarray
 
     - Output parameters: