No default is present. This basically equals the velocity of the wobble, so increasing the value will cause the image to wobble more quickly, decreasing it does the reverse. This particular parameter adjusts the speed of any horizontal wobbling effect and therefore applies only for mode equal to 0 or 2. In general factors of between 4 and 12 appear to give the best results. Remember that as you increase this your image may appear to disappear off the side of the applet.
Larger values can give a jagged appearance to the effect.
The fourth and final effects parameter, this is basically the multiplier used to generate the sine effect. If this parameter is set to its default of 0 the applet will simply center the image within the displayed window. However, if your image needs to be offset in the horizontal plane then use this parameter. This allows you to provide an offset to the graphic displayed below the wobbling image. This particular parameter will alter the horizontal offset, see below for the parameter to alter the vertical offset.