Area scaling for Bubble Plots

Hi, I am currently plotting Bubble plots for various kinds of multivariate data in a GUI, which has a slider determining the scaling factors for the areas of the bubbles. But my data is so vast and diverse, that I am finding it impossible to set a scale for my Bubble radius vector in the plot. Is there any way to modify the vector that could help me in defining the radius of the bubbles. I tried normalizing the vector, but the sizes of the bubbles are not very distinguishable.

Thanks

Cheers Kris