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RegModels.ExpFit Method
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Fits simple exponential equation to data.

Syntax
C#
Visual Basic
public static void ExpFit([In] TVec B, [In] TVec X, [In] TVec Y, [In] TVec Weights);
Parameters
Parameters 
Description 
[In] TVec B 
Returns regression coefficients for simple exponent function. 
[In] TVec X 
Vector of independent variable. 
[In] TVec Y 
Vector of dependent variable. 
[In] TVec Weights 
Weights (optional). Weights are used only if they are set. 
Remarks

The routine fits equations to data by minimizing the sum of squared residuals. The observed values obey the following equation: 

 

 

See Also
Example

In the following example we generate some data. Then we fit simple exponential function to this data and retreive it's regression coefficients.

using Dew.Math; using Dew.Stats.Units; namespace Dew.Examples { private void Example(Steema.TeeChart.Styles.Line line1, Steema.TeeChart.Styles.Line line2) { Vector X = new Vector(100); Vector Y = new Vector(100); Vector B = new Vector(0); Vector YHat = new Vector(0); X.Ramp(-5.0, 0.05); // x= -5.0, -4.95, ... -0.05 Y.RandGauss(3.5, 0.12); // sample data // calculate coefficients RegModels.ExpFit(B,X,Y,null); // evaluate y by using calculated coefficients RegModels.ExpEval(B,X, YHat); MtxVecTee.DrawValues(X,Y,line1,false); MtxVecTee.DrawValues(X,YHat,line2,false); } }
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