Quadric modelling project

Hello everyone,

I am trying to get some help getting started on a project, just getting some direction and advice for now. I am hoping eventually to get this done using visual basic and developping a nice GUI by the end of this project, but its going to be a while until I get there. I am really trying to get backround information and understand what the best way to proceed would be using excel or VBA, macros etc...

Basically this is the goal,

A user marks cells in a 100x100 grid with an x or any symbol.

These points represent the maximum of a curve such as this one quadratic.png
Of which the equation used to generate the curve is known, so individual values can be calculated.

Based on this marked point, on a separate sheet, the location of the original mark gets assigned the value at x=0 on the curve shown above, all ajacent cells would get the value at x=1, then x=2 and so on until it reaches the end of the the 100x100 grid.

The goal is that that by plotting a surface chart of the 100x100 grid, I should end up with a quadric similar to this: image009.gif

So far I have just been toying with the concept and have managed a very rudamentary and simplistic version which sets the marked point with the value of the x=0 (or 1000 if we use the example curve above). On a next sheet, based on the known depreciation of the equation being used, calculates all values from left to right, another sheet does right to left, another top to bottom and lastly bottom to top. The last sheet then simply summs all these 100x100 grids toghether. Unfortunatly this only means I end up with a vertical and horizontal representation of the curve shown above.

Unfortunatly I don't think I am explaining this very well, I hope some of you can see what I mean? I am not looking for any code or anything, just a discussion on ideas of how such a 3D Quadric could be generated at a specific point based on a pre-determined 2D quadratic. So far I have been playing around with Circular references but I feel that there must be a better way to perform such a calculation. Any advice or concepts are welcome.

Regards and many thanks

vonb3ta,

I'm not sure I get it but in the attached I have created a surface area chart in excel using the Circular paraboloid equation I found on Wiki

x^2/a^2 + y^2/a^2 - z = 0

x & y go from -50 to 50 and the result is calculated. In the name manager I have created a name called constant which is a in the equation. I then created a surface area chart in Excel which I looks good.

Does this help?

Regards

David