Jonathan, Thanks adding the Per Image parameter Settings to the formula parser! Also, thanks for allowing parameters to be set in the formula file. A question: I have never known what the axis symmetry named: (XAXIS_NOPARM) [in your example formula] actually does. It is listed in the 20.0 docs but no explanation is given. I also don't understand right off what: XAXIS_NOREAL and XAXIS_NOIMAG do. I found the following description of ORIGIN symmetry at: http://www.math.hmc.edu/calculus/tutorials/transformations/symmetry_origin.p df f(?x) = ?f(x) for all x in the domain. Here is an intuitive way to view this symmetry: If you start at a point on the curve, draw a line segment through that point and the origin, and extend it an equal distance past the origin, you arrive at another point on the curve. I can see how that could be extended to: pixel(-x,y) = pixel(x,-y) Thanks for any help on XAXIS_NOPARM, XAXIS_NOREAL and XAXIS_NOIMAG. (Are these described in any later unreleased developer docs?) [I know I should create a parm file with an asymmetrical fractal in it and apply all the symmetries to see what they look like, but I was hoping that there was an explanation of these already typed in somewhere. I am also in the process of moving from a failing Win98 machine to an XP machine and am temporarily up to my ears in alligators. ;o] Perhaps there should be descriptions in the docs of what the more obscure symmetries do, since some of them are non-intuitive -- at least to me... - Hal Lane ######################### # hallane@earthlink.net <mailto:hallane@earthlink.net> # #########################