--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2008-09-18  David Bateman  <dbateman@free.fr>
+
+	* DLD-FUNCTIONS/fftw.cc (Ffftw): Clarify the documentation.
+
 2008-09-19  David Bateman  <dbateman@free.fr>
 
 	* data.cc (SINGLE_TYPE_CONCAT, DO_SINGLE_TYPE_CONCAT): New macros

--- a/src/DLD-FUNCTIONS/fftw.cc
+++ b/src/DLD-FUNCTIONS/fftw.cc
@@ -42,17 +42,19 @@
 \n\
 Manage FFTW wisdom data. Wisdom data can be used to significantly\n\
 accelerate the calculation of the FFTs but implies an initial cost\n\
-in its calculation. The wisdom used by Octave can be imported directly,\n\
-usually from a file /etc/fftw/wisdom, or @dfn{fftw} can be used\n\
-to import wisdom. For example\n\
+in its calculation. When the FFTW libraries are initialized, they read\n\
+a system wide wisdom file (typically in @file{/etc/fftw/wisdom}), allowing wisdom\n\
+to be shared between applications other than Octave. Alternatively, the\n\
+@code{fftw} function can be used to import wisdom. For example\n\
 \n\
 @example\n\
 @var{wisdom} = fftw ('dwisdom')\n\
 @end example\n\
 \n\
 will save the existing wisdom used by Octave to the string @var{wisdom}.\n\
-This string can then be saved in the usual manner. This existing wisdom\n\
-can be reimported as follows\n\
+This string can then be saved to a file and restored using the @code{save}\n\
+and @code{load} commands respectively. This existing wisdom can be reimported\n\
+as follows\n\
 \n\
 @example\n\
 fftw ('dwisdom', @var{wisdom})\n\
@@ -62,7 +64,7 @@
 \n\
 During the calculation of fourier transforms further wisdom is generated.\n\
 The fashion in which this wisdom is generated is equally controlled by\n\
-the @dfn{fftw} function. There are five different manners in which the\n\
+the @code{fftw} function. There are five different manners in which the\n\
 wisdom can be treated, these being\n\
 \n\
 @table @asis\n\
@@ -105,10 +107,8 @@
 \n\
 Note that calculated wisdom will be lost when restarting Octave. However,\n\
 the wisdom data can be reloaded if it is saved to a file as described\n\
-above.  Also, any system-wide wisdom file that has been found will\n\
-also be used. Saved wisdom files should not be used on different\n\
-platforms since they will not be efficient and the point of calculating\n\
-the wisdom is lost.\n\
+above. Saved wisdom files should not be used on different platforms since\n\
+they will not be efficient and the point of calculating the wisdom is lost.\n\
 @seealso{fft, ifft, fft2, ifft2, fftn, ifftn}\n\
 @end deftypefn")
 {