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+--- Thread: 3 Point Neville's Method (/thread-5306.html)
3 Point Neville's Method - Eddie W. Shore - 12-10-2015 08:57 PM
HP Prime Program: NEVILLE3
Input: lx and ly and list of three elements, {x0, x1, x2} and {y0, y1, y2}, respectively, and x is the target point.
Code:
EXPORT NEVILLE3(lx,ly,x)
BEGIN
// Neville 3-Point Approx.
// EWS 2015-12-07
LOCAL la,a,y,k,n;
la:={0}; // for consistency
FOR k FROM 1 TO 3 DO
IF k==3 THEN
a:=((lx(3)-x)*la(2)+(x-lx(1))*
la(3))/(lx(3)-lx(1));
ELSE
a:=((lx(k+1)-x)*ly(k)+(x-lx(k))*
ly(k+1))/(lx(k+1)-lx(k));
END;
la:=CONCAT(la,{a});
END;
y:=la(4); RETURN y;
END;Example 1;
lx = {16, 64, 100}
ly = {0.25, 0.125, 0.1}
x = 81
Result: 0.1058511078
Example 2:
lx = {-2, 0, 2}
ly = {11, 4, 11}
x = 3
Details and sources:
http://edspi31415.blogspot.com/2015/12/hp-prime-and-casio-prizm-3-point.html