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quasi
Posts:
11,467
Registered:
7/15/05


Re: Help with creating a function
Posted:
Nov 19, 2013 3:48 AM


quasi wrote: >quasi wrote: >>quasi wrote: >>>Robert Crandal wrote: >>>> >>>>Suppose I have the following XY data set: >>>> >>>>X Y >>>>  >>>>0 1 >>>>1 1 >>>>2 2 >>>>3 3 >>>>. . >>>>. . >>>>N N >>>> >>>>Can this be represented with a math function? >>>> >>>>(Only consider positive integers >= 0) >>> >>>It's already a function since for each x in the domain, there >>>is a unique y. >>> >>>Presumably you want a "formula". >>> >>>The function f defined on the set of nonnegative integers >>>by the formula >>> >>> f(x) = ((x1)*(((2*x1)/abs(2*x1))+1)/2)+1 >>> >>>is not pretty but it works. >> >>Here's a simple one based on the floor function. >> >> f(x) = x + floor(1/(x+1)) > >This one uses factorials. > > f(x) = x + (1/2)*(1  (1)^(x+1)!)
Here's a minor variation of the above factorial version using only arithmetic operations (including exponentiation).
f(x) = x + (1/2)*(1  (1)^(2^x))
quasi



