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feval

Class: NonLinearModel

Evaluate nonlinear regression model prediction

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].

Input Arguments

mdl

Nonlinear regression model, constructed by fitnlm.

Xnew1,Xnew2,...,Xnewn

Predictor components. Xnewi can be one of:

  • Scalar

  • Vector

  • Array

Each nonscalar component must have the same size (number of elements in each dimension).

If you pass just one Xnew array, Xnew can be a table, dataset array, or an array of doubles, where each column of the array represents one predictor.

Output Arguments

ypred

Predicted mean values at Xnew. ypred is the same size as each component of Xnew.

Examples

expand all

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

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 auto. The data contain some observations with NaN, so compute the mean using nanmean.

Xnew = nanmean([Horsepower Weight]);
MPGnew = feval(mdl,Xnew)
MPGnew = 21.8073

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.