DC Offset	Amp	Freq	Phase

Global controls

Vector of coefficients for the above shown gradient:

[[0.500 0.500 0.500] [0.500 0.500 0.500] [1.000 1.000 1.000] [0.000 0.333 0.667]]

To sample the gradient and produce a seq of N RGBA colors:

(require '[thi.ng.color.gradients :as grad])

(grad/cosine-gradient
  100 [[0.500 0.500 0.500] [0.500 0.500 0.500] [1.000 1.000 1.000] [0.000 0.333 0.667]]))

thi.ng/color cosine gradient generator