feval

Evaluate nonlinear regression model prediction

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Syntax

ypred = feval(mdl,Xnew1,Xnew2,...,Xnewn)

Description

ypred = feval(mdl,Xnew1,Xnew2,...,Xnewn) returns the predicted response of mdl to the input [Xnew1,Xnew2,...,Xnewn].

example

Examples

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Open Live Script

Create a nonlinear model for auto mileage based on the carbig data. Predict the mileage of an average car.

Load the data and create a nonlinear model. 

load carbig
tbl = table(Horsepower,Weight,MPG);
modelfun = @(b,x)b(1) + b(2)*x(:,1).^b(3) + ...
    b(4)*x(:,2).^b(5);
beta0 = [-50 500 -1 500 -1];
mdl = fitnlm(tbl,modelfun,beta0);

Find the predicted mileage of an average car. The data contains some missing (NaN) observations, so compute the mean using mean with the 'omitnan' option.

Xnew = mean([Horsepower Weight],'omitnan');
MPGnew = feval(mdl,Xnew)
MPGnew = 
21.8073

Input Arguments

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Nonlinear regression model, specified as a NonLinearModel object created using fitnlm.

New input predictor values, specified as a vector, matrix, or table.

  • If you pass multiple inputs Xnew1,Xnew2,...,Xnewn and each includes observations for one predictor variable, then each input must be a vector. Each vector must have the same size. If you specify a predictor variable as a scalar, then feval expands the scalar argument into a constant vector of the same size as the other arguments.

  • If you pass a single input Xnew1, then Xnew1 must be a matrix or table.

    • If Xnew1 is a matrix, it must have the same number of variables (columns) in the same order as the predictor input used to create mdl. Note that Xnew1 must also contain any predictor variables that are as predictors in the fitted model. All variables used in to create mdl must be numeric. To treat numerical predictors as categorical, specify the predictors using the CategoricalVars name-value argument of fitlmcens.

    • If Xnew1 is a table, it must contain predictors that have the same names as predictors in the PredictorNames property of mdl.

Data Types: single | double | table

Output Arguments

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Predicted response values at Xnew1,Xnew2,...,Xnewn, returned as a numeric vector.

Alternatives

predict gives the same predictions, but uses a single input array with one observation in each row, rather than one component in each input argument. predict also gives confidence intervals on its predictions.

random predicts with added noise.

Version History

Introduced in R2012a

See Also

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