class Math is

==============================================================================
== Author:  Michael Cahill
== Version: 1.0
== Date:    15 April 1997
== Short:   Standard library class containing mathematical functions
==
== This class contains routines to carry out the standard mathematics
== functions, including constants, trigonometric functions, logarithms
== and exponentials. All angles are in radians.
==
==============================================================================

uses

interface

    creation is
	== Create a new math object
      do
 	-- No creation necessary   
      end creation

  routines

	pi -> (_pi: Real) is builtin
	  == returns ratio of circumference to diameter of a circle
	end pi

	e -> (_e: Real) is builtin
	  == returns the base of natural (Napier) logarithms
	end e

	sin(theta : Real) -> (result : Real) is builtin
	  == returns the sine of theta
	pre
		theta <> nil
	end sin

	cos(theta : Real) -> (result : Real) is builtin
	  == returns the cosine of theta
	pre
		theta <> nil
	end cos

	tan(theta : Real) -> (result : Real) is builtin
	== returns the tangent of theta
	pre
		theta <> nil
	end tan

	arcsin(x : Real) -> (result : Real) is builtin
	  == returns the angle whose sine is x
	pre
		x <> nil and x >= -1.0 and x <= 1.0
	end arcsin

	arccos(x : Real) -> (result : Real) is builtin
	  == returns the angle whose cosine is x
	pre
		x <> nil and x >= -1.0 and x <= 1.0
	end arccos

	arctan(x : Real) -> (result : Real) is builtin
	  == returns the angle whose tangent is x
	pre
		x <> nil
	end arctan

	sinh(theta : Real) -> (result : Real) is builtin
	  == returns the hyperbolic sine of theta
	pre
		theta <> nil
	end sinh

	cosh(theta : Real) -> (result : Real) is builtin
	  == returns the hyperbolic cosine of theta
	pre
		theta <> nil
	end cosh

	tanh(theta : Real) -> (result : Real) is builtin
	  == returns the hyperbolic tangent of theta
	pre
		theta <> nil
	end tanh

	arcsinh(x : Real) -> (result : Real) is builtin
	  == returns the angle whose hyperbolic sine is x
	pre
		x <> nil
	end arcsinh

	arccosh(x : Real) -> (result : Real) is builtin
	  == returns the angle whose hyperbolic cosine is x
	pre
		x <> nil and x >= 1.0
	end arccosh

	arctanh(x : Real) -> (result : Real) is builtin
	  == returns the angle whose hyperbolic tangent is x
	pre
		x <> nil and x < -1.0 or x > 1.0
	end arctanh

	arctan2(y : Real, x : Real) -> (result : Real) is builtin
	  == returns the angle whose tangent is the gradient of
	  == the line joining (0, 0) to (x, y)
	pre
		x <> nil and y <> nil
	end arctan2

	log(x : Real) -> (result : Real) is builtin
	  == returns the natural logarithm of x
	pre
		x <> nil and x > 0
	end log

	exp(x : Real) -> (result : Real) is builtin
	  == returns the exponential of x (i.e. e ^ x)
	end exp

	log10(x : Real) -> (result : Real) is builtin
	  == returns log to the base 10 of x
	pre
		x <> nil and x > 0
	end log10

end class