Polynom(V0.1) in Java by Manuel Hölß.
About
------------------------------
Polynom is a small program written in Java to create
polynomial visually by giving its values on some points.
These points can be entered, moved and deleted
interactively on the screen. The program takes these
points and calculates an interpolating polynomial with
a gaussian agorithm.
Documentation
------------------------------
When starting the Program shows the interpolating polinimial
of the points (-1,1), (0,0), (1/2,1/4), (1,1) which is the
Parabola
P(x) = x^2 .
The coeffitients a0, a1, ... with
P(x) = a0 + a1 x + a2 x^2 + ...
and b0, b1, ...
with
P(x) = b0(x+b1(x+b2(...)))
are given in the drawing plane.
Click on one of the blue marked points and try to move it.
The curve and the shown coeffitients will be adopted to the
order-3 polynomial which fits the changed positions of the
points.
In the frame on the right the coeffitients are written in one
line for each representation which can easily copied and pasted
to whereever you need them.
The buttons "><" and "<>" allow to zoom in and out in
x-direction.
The buttons "+" and "-" allow adding and deleting points. The
grade of the interpolating polynomial in- resp. decreases by
one when adding or deleting a point.
The "move"- Button switches back to move-mode.
bi2expr
------------------------------
A small helper program which converts the series of coefficients
b0 b1 ... as given by Polynom into an expression which is i
interpreted e.g. by gnuplot.
Bugs and limitations
------------------------------
* With a higher Number of points (20-30), the numerics becomes
instable and the resulting poinomial does not fit them anymore.
* Zooming in y-direction and shifting of the drawing-plane is
not possible. That ist because for my purpose I needed polynomials
which had values between +1 and -1 in an interval almost symmetric i
arount 0.
* A quit-button would not be bad.