PolyFit(pList, var)

pList
A list with datapoints given in a [N,2] matrix. This list should be greater than 1 and less than 11.

var
Optional variable for the returned polynomial. If not given, then var=x.

Description

Finds a unique polynomial function of order N-1 through the given N data points.

Examples


Finds the line between the point [1,3] and [5,7]

PolyFit([[1, 3], [5, 7]])
Plot(x+2)

Finds the parabolic curve through the points [2,4], [3,1], [5,7]

PolyFit([[2, 4], [3, 1], [5, 10]])
Plot(2.5x^2-15.5x+25)

Finds the cubic curve through the points [0,1], [2,5], [3,4], [5,7]

PolyFit([[0, 1], [2, 5], [3, 4], [5, 7]])
Plot((11x^3)/30+(-17x^2)/6+(31x)/5+1)

References

http://mathworld.wolfram.com/LagrangeInterpolatingPolynomial.html
http://en.wikipedia.org/wiki/Lagrange_polynomial
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Functions
A
abs(z)
AiryAi(z)
AiryBi(z)
AlternatingSeries(n, [terms])
Angle(A, B)
Animate(variable, start, end, [step], [value], [fps])
Apart(f(x), x)
Append(expression1, expression2)
Arg(z)
B
BarPlot(list1, frequency1, ...)
Bernoulli(n, [z])
BesselI(v, z)
BesselJ(v, z)
BesselK(v, z)
BesselY(v, z)
Beta(m, n)
Binomial(n, r)
BinomialCDF(n, p, x)
BinomialPDF(n, p, x)
BodePlot(function, variable, minimum, maximum, mode)
BoxPlot(x, [frequency1], [x2], [frequency2], ...)
Button(name, [list], [value])
C
Call(function, parameter1, parameter2, ...)
Caps(string, index, [mode])
Catalan(n)
Ceil(z)
cFrac(n, [terms])
Char(x)
ChebyshevT(n, z)
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CheckBox(variable, [value])
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ChiSquarePDF(x, df)
Cholesky(A)
Choose(test1, value1, test2, value2, ...)
Ci(z)
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clip(x, [min], [max])
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Command(setting)
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CubicFit([x], y)
CubicFitModel([x], y)
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D
D(f(x), x, [n])
Date(letter)
Dawson(z)
Degree(expression)
DEGtoDMS(angle, [digits])
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Denominator(expression)
Det(A)
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Dirichlet_Lambda(z)
Divergence([varlist], vector, [mode])
Divisors(n)
DivisorSigma(n)
Dot(A, B)
DSolve(equation, dependent(independent), values, mode=1)
Duf(function, [varlist], [point], [direction])
dynamic(name, value)
E
Ei(z)
Eigenvalues(A)
Eigenvectors(A)
Else If(condition)
Erf(z)
Erfc(z)
Error(string)
Euler(n, [z])
Eulerian(n, k)
Eval(function, variable, value)
Exp(z)
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ExpConvert(expression)
ExpFit([x], y)
ExpFitModel([x], y)
ExpFitPlot([x], y)
ExponentialFit([x], y)
ExponentialFitModel([x], y)
ExponentialFitPlot([x], y)
Extract(expression, position, [length])
F
Factor(expression)
Factorial(n)
Fcdf(lower, upperbound, numerator, denominator)
fDiff(f(x,y,z,..), (x,y,z,...))
Fibonacci(n, [z])
Finance(PV, FV, Pmt, i, n, [mode=0])
FindFit(function, variable, [x], y)
FindFitModel(function, variable, [x], y)
FindFitPlot(function, variable, [x], y)
Flatten(matrix)
Floor(z)
FourierCos(f(x), x, w)
FourierExpSeries(f(x), x, n)
FourierSeries(f(x), x, [n], [mode])
FourierSin(f(x), x, w)
FourierTrigSeries(f(x), x, n)
fPart(z)
Fpdf(x, d1, d2)
FractalPlot(expression, ...)
FresnelCos(z)
FresnelSin(z)
FullRectSineWave(x, [T])
Function(function, parameter1, parameter2, ...)
G
Gamma(z)
GCD(n1, n2)
GegenbauerC(n, a, z)
GeoCDF(p, x)
GeoPDF(p, x)
Gradient(function, [varlist], [mode])
Gudermannian(z)
H
HalfRectSineWave(x, [T])
HankelH1(v, z)
HankelH2(v, z)
Harmonic(z)
Heaviside(x)
HermiteH(n, z)
Hessian(function, [varlist], [mode])
HRStoHMS(hours, [digits])
http(url, [filter])
Hypergeom_2F1(a, b, c, z, [mode])
I
Identity(n)
iDiff(f(x,y,z,..), dependant_variables, independant_variables)
If(condition)
iLaplace(F(s), s)
Im(z)
ImagePlot(data)
ImaginaryPart(expression)
ImplicitPlot(expression, ...)
Include(filename)
Insert(expression, item, position)
Integrate(f(x), x, [a], [b])
Inverse(A)
InverseNormal(p, [mu], [sigma])
invGudermannian(z)
iPart(z)
IsList(expression)
IsMatrix(expression)
IsNumber(expression)
IsPoly(expression, variable)
IsPrime(n)
J
Jacobian(function, [varlist], [point])
json(data, [filter])
JuliaPlot(expression, ...)
K
KelvinBei(v, z)
KelvinBer(v, z)
KelvinKei(v, z)
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L
LaguerreL(n, z)
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LCM(n1, n2)
Left(expression)
LegendreP(n, z)
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Length(expression)
Li(x)
Limit(function, variable, point, [direction])
LinearFit([x], y)
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List(length)
ListMap(list, name, [value])
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Ln(z)
LnFit([x], y)
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local(name, value)
Log([n], z)
LogisticFit([x], y)
LogisticFitModel([x], y)
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M
Matrix(rows, [columns])
MatrixLU(matrix, [mode])
MatrixMap(matrix, name, [value])
MatrixQR(A)
MatrixSVD(A)
Max(number, ...)
Mean(list)
MedianFit([x], y)
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Mod(m, n)
Multinomial(nList)
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N
nCr(n, r)
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Norm(z)
NormalCDF(lower, upper, [mu], [sigma])
NormalPDF(x, mu, sigma)
nPr(n, r)
nPrimes(n)
nRoot(z, n, [mode])
P
ParametricPlot(expression, ...)
ParametricPlot3D(expression, ...)
Part(expression, n)
pDiff(f(x,y,z,..), dependent_variables, dependent_equations, independent_variables)
Pi_Digits(n)
Plot(expression, ...)
Plot3D(expression, ...)
Pochhammer(n, k)
PoissonCDF(mu, x)
PoissonPDF(mu, x)
PolarPlot(expression, ...)
PolyDivide(f(z), g(z))
PolyFit(pList, var)
PolyGamma(n, z)
PolyGCD(polynomial1, polynomial2)
PolyLCM(polynomial1, polynomial2, [mode=1])
PolyLog(n, z)
PowerExpand(expression)
PowerFit([x], y)
PowerFitModel([x], y)
PowerFitPlot([x], y)
Prime(n)
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Product(f(n), n, start, end)
Psi(z)
Q
QuadraticFit([x], y)
QuadraticFitModel([x], y)
QuadraticFitPlot([x], y)
QuarticFit([x], y)
QuarticFitModel([x], y)
QuarticFitPlot([x], y)
Quotient(f(x), g(x))
R
Random(min, max, [size1], [size2])
Re(z)
RealPart(expression)
Remainder(f(x), g(x))
Replace(expression, old, new)
Reshape(matrix)
Return(expression)
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Right(expression)
RK4(function, t, y, a, b, y0, N=10)
RK45(function, t, y, a, b, y0, Tol=10E-5, hmax=0.25, hmin=10E-6, N=20)
Round(number, digits)
RowReduce(A)
S
SawToothWave(x, [T])
Sequence(f(x), x, start, end, [step], [start term], [number of terms])
Series(f(z), z, n)
Shi(z)
Si(z)
Sign(z)
SimplifyFunction(expression)
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sin(z)
SinFit([x], y)
SinFitModel([x], y)
SinFitPlot([x], y)
Size(list)
Slider(variable, start, end, [step], [initial value])
Solve(f(x), x, [guess])
SolveSystem(equations, [variables], [guesses])
Sort(list)
SphericalPlot3D(expression, ...)
Sqrt(z)
SquareWave(x, [T])
StaircaseWave(x, [T])
StandardDeviation(list)
String(expression1, expression2, ...)
StudentTCDF(x, df)
StudentTPDF(x, df)
Sum(f(n), n, start, end)
SurfaceNormal(function, [varlist], [point])
T
Together(expression)
Trace(variable)
Transpose(A)
TriangleWave(x, [T])
TrigConvert(expression)
TrigExpand(expression)
TrigReduce(expression)
V
Variables(expression)
Variance(list)
VectorPlot(list, ...)
VectorPlot3D(list, ...)
W
While(condition)
Z
Zeta(z, [a])