Interpolation with positivity constraint

Please choose:

My own (x,y) -data Degree n= Important: 1 <= n <= 50 !

Please write your (x,y) data here, x and y separated by blank or comma, no parentheses, each pair on a new line

(x,y)=
Synthetic data

Choose a function:
f(x) = (x2)1/3
f(x) = 1/(1+25x2)
f(x) = sin(2*pi*x)
f(x) = tanh(x)
f(x) = exp(x)
Input of a self defined function:
Please type the evaluation program of your function here using FORTRAN rules. Your final statement must be
      fu= some expression you computed before or just here depending on x
You may use the constants pi, e(=exp(1)), sqrt2(=1.414...), the integer variables i,j,k, the logicals bool1,bool2,bool3 and the double precision variables sum,h1,h2,h3,h4,y(100),z(100),a(100,100) which are all intialized with zero resp. .false. . The routine has the parameters x (double, input) and fu (double out). never change x!. first is a local integer and set 0 before calling the function the first time. You may use this in order to initialize some local data and set it 1 afterwards to avoid multiple such initialization. Your settings of the local variables are preserved during program execution.

Please specify the degree here:
n = Important: 1 <= n <= 50 !

Please specify the interval for the x-data [a,b]
a = b =

How should the x-data be distributed ?
equidistant (hence x(i)=a+(b-a)*i/n )
transformed Chebyshev abscissae
(hence (a+b)/2+(b-a)/2*cos((2i+1)pi/(2n+2)) )

Do not print divided differences
Print divided differences

Do not print the polynomial formula
Print polynomial formula

Please select your choice for the shift of the ordinates
no shift at all: requires strictly positive yi
shift (if any) such that yi >= 1 ∀ i
userdefined: shift =

Warning!!! - This may take some time.

Click on "evaluate", in order to submit your input.

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27.09.2018