Linear and nonlinear regression calculator
Calculator applies various types of regression (linear, exponential, logarithmic, etc.) to your meassurement data and finds out function, which fits them best.

Beta version#

BETA TEST VERSION OF THIS ITEM
This online calculator is currently under heavy development. It may or it may NOT work correctly.
You CAN try to use it. You CAN even get the proper results.
However, please VERIFY all results on your own, as the level of completion of this item is NOT CONFIRMED.
Feel free to send any ideas and comments !

Calculation data - measurement points#

Format of input data
x-values
y-values
Maximum polynomial degree
(polynomial with higher order will not be calculated)

Results - approximation of your dataset#

Regression typeApproximation formulaCoefficient of determination R2
Logarithmic regressionShow sourcey=12.2406886256+17.1079184613ln(x)y=-12.2406886256+17.1079184613 \cdot ln\left(x\right)0.945714039
Linear regressionShow sourcey=1534612000000000 x+31771810983500000000y=\frac{153461}{2000000000}~x+\frac{31771810983}{500000000}0.285736587
Polynomial regression of 1-th degreeShow sourcey=1534612000000000 x+63543607924310000000000y=\frac{153461}{2000000000}~x+\frac{635436079243}{10000000000}0.285736587
Polynomial regression of 2-th degreeShow sourcey=12000000000 x2+50566415000000000 x+34557919056110000000000y=\frac{-1}{2000000000}~x^{2}+\frac{5056641}{5000000000}~x+\frac{345579190561}{10000000000}0.268579423
Polynomial regression of 0-th degreeShow sourcey=88y=880
Power regressionShow sourcey=30842099172500000000 x10087113312500000000y=\frac{3084209917}{2500000000}~x^{\frac{1008711331}{2500000000}}-0.019128704
Exponential regressionShow sourcey=184997964509910000000000 e53110000000000 xy=\frac{1849979645099}{10000000000}~e^{\frac{531}{10000000000}~x}-0.942310326

Summary - function best fitting to your data#

Measurement points
Number of points7
Points you entered(10, 1), (2, 2), (20100, 202), (2, 2), (201000, 203), (2, 2), (2010000, 204)
Approximation
Regression typeLogarithmic regression
Function formulaShow sourcey=12.2406886256+17.1079184613ln(x)y=-12.2406886256+17.1079184613 \cdot ln\left(x\right)
Coefficient of determination R20.945714039

Some facts#

  • Approximation of a function consists in finding a function formula that best matches to a set of points e.g. obtained as measurement data.
  • The least squares method is one of the methods for finding such a function.
  • The least squares method is the optimization method. As a result we get function that the sum of squares of deviations from the measured data is the smallest. Mathematically, we can write it as follows:
    i=1n[yif(xi)]2=min.\sum_{i=1}^{n} \left[y_i - f(x_i)\right]^2 = min.
    where:
    • (xi,yi)(x_i, y_i) - coordinations of the i-th measurement point, these are points that we know,
    • f(x)f(x) - the function we are searching for, we want this function to best match to the measurement points,
    • nn - number of measurement points.
  • Depending on used function we say about:
  • The least squares method allow us to find coefficients for above functions (a, b, etc.) to fits best to measurement data.

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