curve fitting

"Curve fitting:

A procedure in which the basic problem is to pass a curve through a set of points, representing experimental data, in such a way that the curve shows as well as possible the relationship between the two quantities plotted. It is always possible to pass some smooth curve through all the points plotted, but since there is assumed to be some experimental error present, such a procedure would ordinarily not be desirable. See also Interpolation.
The first task in curve fitting is to decide (1) how many degrees of freedom (number of unspecified parameters, or independent variables) should be allowed in fitting the points, and (2) what the general nature of the curve should be. Since there is no known way of answering these questions in a completely objective way, curve fitting remains something of an art. It is clear, however, ..."
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