how to find the inital formula from engineering test data

huangyhg

how to find the inital formula from engineering test data
recently, my job seems to work out a mathematic problem.
we did many efforts on engineer test and get a perfect graph curve by discrete data (100 points).  
but my customer are interested on the inital formula for those data. perhaps it’s a function or calculus.....not clear.
unfortunately, engineers and physicists distinguish between continuous data and discrete data.
anyone leads us first step of this cross?
books, software, method?
please do not double post
ttfn
ok, i am new.
i am not sure, where is the right place to ask?
this forum is more topical, but the spreadsheet forum has more traffic.
ttfn
i believe you are asksing how to find a formula by fitting a smmoth curve to the data.  this is also called "regression analysis" by some people.  you can do this to a limited extent in excel. plot the data on an x-y scatter graph (chart ). add a trend line under chart options. select "show formula on graph". you will then have the best fit formula you seek.
if you think you know the form of the equation, you may also use other curve fitting software. as a civil engineer i use a program called smada often for this purpose.
good luck
you can fit unlimited number of functions more or less smooth to your data, but they will not reflect any physical background.
if you start fitting equations that bear some physical sense your fit will be very likely worse because in engineering equations we allways start with some approximations like linearity of the system, orthogonality of parameters etc and do not take into account noise at measurements.
m777182