A Diagram:(Scroll down for text descriptions of the sliders)

What The Sliders Mean:

PHASE: This sets the initial sampling point on the sine wave. In effect, this sets the initial hue for the gradient/palette.

FLOOR: This sets the lowest possible value for the red/green/blue components. If your palette is too dark, or if the value range of your palette is too wide (the darks are very dark, and the lights are very light), then raise your floor.

AMP: This sets the allowed range of possible R/G/B values above the floor. If you want the swatches in your palette to be of similar brightness, lower the amp slider.

FREQ: This is the sets the ratio of sampling frequency to source frequency. Raise this slider to increase the amount of hue shift from swatch to swatch.

SPREAD: This determines how far along the wavelength the R/G/B sample values are taken. The result of a low spread value is reduced saturation in the palette/gradient.