+# trigonometry for DCT, by Shiar
+
+# 1.11.1 200410282330 - cardial mode setting; rad/deg to switch to radians/degrees
+# - convert from/to radians for trig commands if rad mode set
+# 1.11.0 200410152320 - a?(sin|cos|tan)h? actions from math; links in main submenu trig
+
+use strict;
+use warnings;
+
+my $pi = atan2(1, 1) * 4;
+
+$set{card} = 1; # degrees radians grades
+
+%action = (
+ %action,
+
+ 'pi' => [0, sub { $pi }], # pi constant
+
+ 'deg' => [-1, sub { $set{card} = 1 }], # set degrees
+ 'rad' => [-1, sub { $set{card} = 2 }], # set radians
+
+ # trigonometric
+ 'sin' => [1, sub { sin $_[0] }], # sine
+ 'asin' => [1, sub { atan2($_[0], sqrt(1 - $_[0]*$_[0])) }], # inverse sine
+ 'cos' => [1, sub { cos $_[0] }], # cosine
+ 'acos' => [1, sub { atan2(sqrt(1 - $_[0]*$_[0]), $_[0]) }], # inverse cosine
+ 'tan' => [1, sub { sin($_[0]) / cos($_[0]) }], # tangent
+ 'atan' => [1, sub { atan2($_[0], 1) }], # arctangent
+
+ # hyperbolic
+ 'sinh' => [1, sub { (exp($_[0]) - exp(-$_[0])) / 2 }], # hyperbolic sine
+ 'cosh' => [1, sub { (exp($_[0]) + exp(-$_[0])) / 2 }], # hyperbolic cosine
+ 'tanh' => [1, sub { (exp($_[0]) - exp(-$_[0])) / (exp($_[0]) + exp(-$_[0])) }], # hyperbolic tangent (sinh/cosh)
+ 'asinh'=> [1, sub { log(sqrt($_[0]**2+1) + $_[0]) }], # inverse hyperbolic sine
+ 'acosh'=> [1, sub { log(sqrt($_[0]**2-1) + $_[0]) }], # inverse hyperbolic cosine
+ 'atanh'=> [1, sub { log((1+$_[0]) / (1-$_[0])) / 2 }], # inverse hyperbolic tangent
+); # action
+
+push @{$hook{preaction}}, sub {
+ return unless $set{card}==2;
+ # convert user input from radians if necessary
+ $stack[0] /= 360/$pi if $_[1] =~ /^(?:sin|cos|tan)h?$/;
+}; # preaction
+push @{$hook{postaction}}, sub {
+ return unless $set{card}==2;
+ # convert command output to radians if necessary
+ $stack[0] *= 360/$pi if $_[1] =~ /^a(?:sin|cos|tan)h?$/;
+}; # postaction
+
+addmenu(["main", 0], "trig", #todo: in math, not in main
+ qw(sin cos tan asin acos atan),
+ qw(sinh cosh tanh asinh acosh atanh),
+ qw(expm lnp1),
+);
+
+return {
+ author => "Shiar",
+ title => "trigonometry",
+ version => "1.11.1",
+};
+