How do I fit a curve with two independant variables

[Ale_DIMEG]

Hi,
    I should have to fit a model just like the one you mentioned (Z=AX+Bx**2+CY+Dy**2+EXY+F), but my data are not sorted. Unfortunatly I don't know LAbView very much, so I don't understand how I can use your Vi with them... after I add new connections, which kind of modification do I need to do??

Thanks a lot

       Alessandro

[altenbach]

(Since this is a new problem, you should have started a new thread.)

Anyway, your equation is linear in all coefficients, so you can just use the "general LS fit". have a look at my example here:

http://forums.ni.com/ni/board/message?board.id=170&message.id=129944#M129944

(disregard the levenberg-marquardt implementation in the quoted example)