--- a/doc/ChangeLog	Fri Apr 24 20:32:01 2009 -0700
+++ b/doc/ChangeLog	Sun Apr 26 22:19:57 2009 -0700
@@ -1,3 +1,6 @@
+2009-04-26  Rik  <rdrider0-list@yahoo.com>
+	* interpreter/arith.txi: Update section 17.3 (Trigonometry) of arith.txi
+
 2009-04-24  Rik  <rdrider0-list@yahoo.com>
 	* interpreter/arith.txi: Update section 17.2 (Complex Arithmetic) of
 	arith.txi

--- a/doc/interpreter/arith.txi	Fri Apr 24 20:32:01 2009 -0700
+++ b/doc/interpreter/arith.txi	Sun Apr 26 22:19:57 2009 -0700
@@ -103,7 +103,7 @@
 @node Trigonometry
 @section Trigonometry
 
-Octave provides the following trigonometric functions.  Angles are
+Octave provides the following trigonometric functions where angles are
 specified in radians.  To convert from degrees to radians multiply by
 @iftex
 @tex
@@ -113,7 +113,12 @@
 @ifinfo
 @code{pi/180}
 @end ifinfo
- (e.g., @code{sin (30 * pi/180)} returns the sine of 30 degrees).
+(e.g., @code{sin (30 * pi/180)} returns the sine of 30 degrees).  As
+an alternative, Octave provides a number of trigonometric functions
+which work directly on an argument specified in degrees.  These functions
+are named after the base trigonometric function with a @samp{d} suffix.  For
+example, @code{sin} expects an angle in radians while @code{sind} expects an
+angle in degrees.
 
 @DOCSTRING(sin)
 @DOCSTRING(cos)
@@ -143,22 +148,21 @@
 @DOCSTRING(acsch)
 @DOCSTRING(acoth)
 
-Each of these functions expects a single argument.  For matrix arguments,
-they work on an element by element basis.  For example,
+@DOCSTRING(atan2)
 
+Octave provides the following trigonometric functions where angles are
+specified in degrees.  These functions produce true zeros at the appropriate
+intervals rather than the small roundoff error that occurs when using
+radians.  For example:
 @example
 @group
-sin ([1, 2; 3, 4])
-     @result{}  0.84147   0.90930
-         0.14112  -0.75680
+cosd (90)
+     @result{} 0
+cos (pi/2)
+     @result{} 6.1230e-17
 @end group
 @end example
 
-@DOCSTRING(atan2)
-
-In addition to the trigonometric functions that work with radians,
-Octave also provides the following functions which work with degrees.
-
 @DOCSTRING(sind)
 @DOCSTRING(cosd)
 @DOCSTRING(tand)
@@ -193,6 +197,8 @@
 
 @DOCSTRING(ceil)
 
+@DOCSTRING(cross)
+
 @DOCSTRING(del2)
 
 @DOCSTRING(factor)
@@ -236,9 +242,9 @@
 @node Special Functions
 @section Special Functions
 
-@DOCSTRING(besselj)
+@DOCSTRING(airy)
 
-@DOCSTRING(airy)
+@DOCSTRING(besselj)
 
 @DOCSTRING(beta)
 
@@ -248,6 +254,10 @@
 
 @DOCSTRING(bincoeff)
 
+@DOCSTRING(commutation_matrix)
+
+@DOCSTRING(duplication_matrix)
+
 @DOCSTRING(erf)
 
 @DOCSTRING(erfc)
@@ -263,12 +273,6 @@
 @anchor{doc-gammaln}
 @DOCSTRING(lgamma)
 
-@DOCSTRING(cross)
-
-@DOCSTRING(commutation_matrix)
-
-@DOCSTRING(duplication_matrix)
-
 @node Coordinate Transformations
 @section Coordinate Transformations
 
@@ -283,16 +287,16 @@
 @node Mathematical Constants
 @section Mathematical Constants
 
+@DOCSTRING(e)
+
+@DOCSTRING(pi)
+
 @DOCSTRING(I)
 
 @DOCSTRING(Inf)
 
 @DOCSTRING(NaN)
 
-@DOCSTRING(pi)
-
-@DOCSTRING(e)
-
 @DOCSTRING(eps)
 
 @DOCSTRING(realmax)

--- a/scripts/elfun/acosd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acosd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} acosd (@var{x})
-## Compute the inverse cosine of an angle in degrees.
-## @seealso{acos, cosd, asecd}
+## Compute the inverse cosine in degrees for each element of @var{x}.
+## @seealso{cosd, acos}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/acot.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acot.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} acot (@var{x})
-## Compute the inverse cotangent of each element of @var{x}.
+## Compute the inverse cotangent in radians for each element of @var{x}.
+## @seealso{cot, acotd}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/acotd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acotd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} acotd (@var{x})
-## Compute the inverse cotangent of an angle in degrees.
-## @seealso{atan, tand}
+## Compute the inverse cotangent in degrees for each element of @var{x}.
+## @seealso{cotd, acot}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/acoth.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acoth.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} acoth (@var{x})
 ## Compute the inverse hyperbolic cotangent of each element of @var{x}.
+## @seealso{coth}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/acsc.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acsc.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} acsc (@var{x})
-## Compute the inverse cosecant of each element of @var{x}.
+## Compute the inverse cosecant in radians for each element of @var{x}.
+## @seealso{csc, acscd}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/acscd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acscd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} acscd (@var{x})
-## Compute the inverse cosecant of an angle in degrees.
-## @seealso{acsc, cscd, asecd}
+## Compute the inverse cosecant in degrees for each element of @var{x}.
+## @seealso{cscd, acsc}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/acsch.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/acsch.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} acsch (@var{x})
 ## Compute the inverse hyperbolic cosecant of each element of @var{x}.
+## @seealso{csch}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/asec.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/asec.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} asec (@var{x})
-## Compute the inverse secant of each element of @var{x}.
+## Compute the inverse secant in radians for each element of @var{x}.
+## @seealso{sec, asecd}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/asecd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/asecd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} asecd (@var{x})
-## Compute inverse secant in degrees.
-## @seealso{asec, secd, acscd}
+## Compute the inverse secant in degrees for each element of @var{x}.
+## @seealso{secd, asec}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/asech.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/asech.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} asech (@var{x})
 ## Compute the inverse hyperbolic secant of each element of @var{x}.
+## @seealso{sech}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/asind.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/asind.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} asind (@var{x})
-## Compute the inverse sine of an angle in degrees.
-## @seealso{asin, sind, acosd}
+## Compute the inverse sine in degrees for each element of @var{x}.
+## @seealso{sind, asin}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/atand.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/atand.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} atand (@var{x})
-## Compute the inverse tangent of an angle in degrees.
-## @seealso{acot, tand}
+## Compute the inverse tangent in degrees for each element of @var{x}.
+## @seealso{tand, atan}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/cosd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/cosd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,9 +18,9 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} cosd (@var{x})
-## Compute the cosine of an angle in degrees.  Returns zero in elements
-## for which @code{(@var{x}-90)/180} is an integer.
-## @seealso{cos, sind, tand, acosd, asind, atand}
+## Compute the cosine for each element of @var{x} in degrees.  Returns zero 
+## for elements where @code{(@var{x}-90)/180} is an integer.
+## @seealso{acosd, cos}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/cot.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/cot.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} cot (@var{x})
-## Compute the cotangent of each element of @var{x}.
+## Compute the cotangent for each element of @var{x} in radians.
+## @seealso{acot, cotd, coth}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/cotd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/cotd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} cotd (@var{x})
-## Compute the cotangent of an angle in degrees.
-## @seealso{cot, tand}
+## Compute the cotangent for each element of @var{x} in degrees.
+## @seealso{acotd, cot}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/coth.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/coth.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} coth (@var{x})
 ## Compute the hyperbolic cotangent of each element of @var{x}.
+## @seealso{acoth}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/csc.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/csc.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} csc (@var{x})
-## Compute the cosecant of each element of @var{x}.
+## Compute the cosecant for each element of @var{x} in radians.
+## @seealso{acsc, cscd, csch}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/cscd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/cscd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} cscd (@var{x})
-## Compute the cosecant of an angle in degrees.
-## @seealso{csc, secd, sind, cosd}
+## Compute the cosecant for each element of @var{x} in degrees.
+## @seealso{acscd, csc}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/csch.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/csch.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} csch (@var{x})
 ## Compute the hyperbolic cosecant of each element of @var{x}.
+## @seealso{acsch}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/sec.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/sec.m	Sun Apr 26 22:19:57 2009 -0700
@@ -19,7 +19,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} sec (@var{x})
-## Compute the secant of each element of @var{x}.
+## Compute the secant for each element of @var{x} in radians.
+## @seealso{asec, secd, sech}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/secd.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/secd.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,8 +18,8 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} secd (@var{x})
-## Compute the secant of an angle in degrees.
-## @seealso{sec, cscd, sind, cosd}
+## Compute the secant for each element of @var{x} in degrees.
+## @seealso{asecd, sec}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/sech.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/sech.m	Sun Apr 26 22:19:57 2009 -0700
@@ -20,6 +20,7 @@
 ## -*- texinfo -*-
 ## @deftypefn {Mapping Function} {} sech (@var{x})
 ## Compute the hyperbolic secant of each element of @var{x}.
+## @seealso{asech}
 ## @end deftypefn
 
 ## Author: jwe

--- a/scripts/elfun/sind.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/sind.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,9 +18,9 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} sind (@var{x})
-## Compute the sine of each element of @var{x}.  Returns zero in elements
-## for which @code{@var{x}/180} is an integer.
-## @seealso{sin, cosd, tand, acosd, asind, atand}
+## Compute the sine for each element of @var{x} in degrees.  Returns zero 
+## for elements where @code{@var{x}/180} is an integer.
+## @seealso{asind, sin}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/scripts/elfun/tand.m	Fri Apr 24 20:32:01 2009 -0700
+++ b/scripts/elfun/tand.m	Sun Apr 26 22:19:57 2009 -0700
@@ -18,10 +18,10 @@
 
 ## -*- texinfo -*-
 ## @deftypefn {Function File} {} tand (@var{x})
-## Compute the tangent of an angle in degrees.  Returns zero for elements
-## of for which @code{@var{x}/180} is an integer and @code{Inf} for elements
-## where @code{(@var{x}-90)/180} is an integer.
-## @seealso{tan, cosd, sind, acosd, asind, atand}
+## Compute the tangent for each element of @var{x} in degrees.  Returns zero 
+## for elements where @code{@var{x}/180} is an integer and @code{Inf} for
+## elements where @code{(@var{x}-90)/180} is an integer.
+## @seealso{atand, tan}
 ## @end deftypefn
 
 ## Author: David Bateman <dbateman@free.fr>

--- a/src/data.cc	Fri Apr 24 20:32:01 2009 -0700
+++ b/src/data.cc	Sun Apr 26 22:19:57 2009 -0700
@@ -534,7 +534,8 @@
   "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} atan2 (@var{y}, @var{x})\n\
 Compute atan (@var{y} / @var{x}) for corresponding elements of @var{y}\n\
-and @var{x}.  The result is in the range -pi to pi.\n\
+and @var{x}.  Signal an error if @var{y} and @var{x} do not match in size\n\
+and orientation.\n\
 @end deftypefn")
 {
   octave_value retval;

--- a/src/mappers.cc	Fri Apr 24 20:32:01 2009 -0700
+++ b/src/mappers.cc	Sun Apr 26 22:19:57 2009 -0700
@@ -90,7 +90,8 @@
 DEFUN (acos, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} acos (@var{x})\n\
-Compute the inverse cosine of each element of @var{x}.\n\
+Compute the inverse cosine in radians for each element of @var{x}.\n\
+@seealso{cos, acosd}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -126,7 +127,8 @@
 DEFUN (acosh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} acosh (@var{x})\n\
-Compute the inverse hyperbolic cosine of each element of @var{x}.\n\
+Compute the inverse hyperbolic cosine for each element of @var{x}.\n\
+@seealso{cosh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -226,7 +228,8 @@
 DEFUN (asin, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} asin (@var{x})\n\
-Compute the inverse sine of each element of @var{x}.\n\
+Compute the inverse sine in radians for each element of @var{x}.\n\
+@seealso{sin, asind}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -252,7 +255,8 @@
 DEFUN (asinh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} asinh (@var{x})\n\
-Compute the inverse hyperbolic sine of each element of @var{x}.\n\
+Compute the inverse hyperbolic sine for each element of @var{x}.\n\
+@seealso{sinh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -284,7 +288,8 @@
 DEFUN (atan, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} atan (@var{x})\n\
-Compute the inverse tangent of each element of @var{x}.\n\
+Compute the inverse tangent in radians for each element of @var{x}.\n\
+@seealso{tan, atand}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -320,7 +325,8 @@
 DEFUN (atanh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} atanh (@var{x})\n\
-Compute the inverse hyperbolic tangent of each element of @var{x}.\n\
+Compute the inverse hyperbolic tangent for each element of @var{x}.\n\
+@seealso{tanh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -438,7 +444,8 @@
 DEFUN (cos, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} cos (@var{x})\n\
-Compute the cosine of each element of @var{x}.\n\
+Compute the cosine for each element of @var{x} in radians.\n\
+@seealso{acos, cosd, cosh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -474,7 +481,8 @@
 DEFUN (cosh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} cosh (@var{x})\n\
-Compute the hyperbolic cosine of each element of @var{x}.\n\
+Compute the hyperbolic cosine for each element of @var{x}.\n\
+@seealso{acosh, sinh, tanh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -517,11 +525,13 @@
 @ifnottex\n\
 \n\
 @example\n\
+@group\n\
                          z\n\
                         /\n\
 erf (z) = (2/sqrt (pi)) | e^(-t^2) dt\n\
                         /\n\
                      t=0\n\
+@end group\n\
 @end example\n\
 @end ifnottex\n\
 @seealso{erfc, erfinv}\n\
@@ -1448,7 +1458,8 @@
 DEFUN (sin, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} sin (@var{x})\n\
-Compute the sine of each element of @var{x}.\n\
+Compute the sine for each element of @var{x} in radians.\n\
+@seealso{asin, sind, sinh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -1484,7 +1495,8 @@
 DEFUN (sinh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} sinh (@var{x})\n\
-Compute the hyperbolic sine of each element of @var{x}.\n\
+Compute the hyperbolic sine for each element of @var{x}.\n\
+@seealso{asinh, cosh, tanh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -1551,7 +1563,8 @@
 DEFUN (tan, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} tan (@var{z})\n\
-Compute tangent of each element of @var{x}.\n\
+Compute the tangent for each element of @var{x} in radians.\n\
+@seealso{atan, tand, tanh}\n\
 @end deftypefn")
 {
   octave_value retval;
@@ -1587,7 +1600,8 @@
 DEFUN (tanh, args, ,
     "-*- texinfo -*-\n\
 @deftypefn {Mapping Function} {} tanh (@var{x})\n\
-Compute hyperbolic tangent of each element of @var{x}.\n\
+Compute hyperbolic tangent for each element of @var{x}.\n\
+@seealso{atanh, sinh, cosh}\n\
 @end deftypefn")
 {
   octave_value retval;