indexing
	description: "[

		Cosine function

	]"
	author: ""
	date: "$Date$"
	revision: "$Revision$"

class
	COSINE_SOURCE

inherit
	EM_VIZ_SAMPLE_SOURCE_1D

	EM_VIZ_MATH

create
	make

feature -- Initialization

	make is
			--
		do
			amplitude := 1.0
			x_offset := 0.0
			y_offset := 0.0
			period := 2*Pi
		end

feature -- Access

	amplitude: DOUBLE
			-- Amplitude of cosine

	x_offset: DOUBLE
			-- Offset of cosine in x

	y_offset: DOUBLE
			-- Offset of cosine in y

	period: DOUBLE
			-- Period of cosine

feature -- Element change

	set_amplitude (v: like amplitude) is
			-- Setter
		do
			amplitude := v
		end

	set_x_offset (v: like x_offset) is
			-- Setter
		do
			x_offset := v
		end

	set_y_offset (v: like y_offset) is
			-- Setter
		do
			y_offset := v
		end

	set_period (v: like period) is
			-- Setter
		do
			period := v
		end

feature -- Basic operations

	sample (pos: DOUBLE): DOUBLE is
			--
		do
			Result := amplitude * cosine (2*Pi/period * pos + x_offset) + y_offset
		end

end