feval - Predict responses of generalized linear regression model using one input for

        each predictor - MATLAB ([original](http://www.mathworks.com/help/stats/generalizedlinearmodel.feval.html)) ([raw](?raw))

Predict responses of generalized linear regression model using one input for each predictor

Syntax

Description

[ypred](#btbshi0-ypred) = feval([mdl](#btbshi0%5Fsep%5Fshared-mdl),[Xnew1,Xnew2,...,Xnewn](#btbshi0%5Fsep%5Fshared-Xnew1Xnew2Xnewn)) returns the predicted response of mdl to the new input predictorsXnew1,Xnew2,...,Xnewn.

example

Examples

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Create a generalized linear regression model, and plot its responses to a range of input data.

Generate sample data using Poisson random numbers with two underlying predictors X(:,1) and X(:,2).

rng('default') % For reproducibility rndvars = randn(100,2); X = [2 + rndvars(:,1),rndvars(:,2)]; mu = exp(1 + X*[1;2]); y = poissrnd(mu);

Create a generalized linear regression model of Poisson data.

mdl = fitglm(X,y,'y ~ x1 + x2','Distribution','poisson');

Generate a range of values for X(:,1) and X(:,2), and plot the predictions at the values.

[Xtest1,Xtest2] = meshgrid(min(X(:,1)):.5:max(X(:,1)),min(X(:,2)):.5:max(X(:,2))); Z = feval(mdl,Xtest1,Xtest2); surf(Xtest1,Xtest2,Z)

Input Arguments

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Data Types: single | double | table

Output Arguments

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

For a binomial model, feval uses 1 as theBinomialSize parameter, so the values inypred are predicted probabilities. To return the numbers of successes in the trials, use the predict function and specify the number of trials by using the 'BinomialSize' name-value pair argument.

For a model with an offset, feval uses 0 as the offset value. To specify the offset value used when you fit a model, use thepredict function and the'Offset' name-value pair argument.

Tips

• A regression object is, mathematically, a function that estimates the relationship between the response and predictors. The feval function enables an object to behave like a function in MATLAB®. You can pass feval to another function that accepts a function input, such as fminsearch and integral.
• feval can be simpler to use with a model created from a table or dataset array. When you have new predictor data, you can pass it to feval without creating a table or matrix.

Alternative Functionality

• predict gives the same predictions asfeval if you use the default values for the 'Offset' and'BinomialSize' name-value pair arguments of predict. The prediction values can be different if you specify other values for these arguments. Thepredict function also returns confidence intervals on its predictions. Note that the predict function accepts a single input argument containing all predictor variables, rather than multiple input arguments with one input for each predictor variable.
• random predicts responses with added noise.

Extended Capabilities

Version History

Introduced in R2012a