modelObj: Create an Object of Class modelObj

Description Usage Arguments Details Value Examples

Description

A utility function to transfer user defined models and estimation methods to an object of class modelObj.

Usage

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buildModelObj(model, solver.method=NULL, solver.args=NULL, 
              predict.method=NULL, predict.args=NULL)

Arguments

model

An object of class formula; the model.

solver.method

An object of class character specifying the name of the R function to be used to obtain parameter estimates. Or, the function to be used to obtain parameter estimates. For example, ‘lm’, ‘glm’, or ‘rpart’. The specified modeling function MUST have a corresponding predict method.

solver.args

An object of class list containing additional arguments to be sent to solver.method. Arguments must be provided as a list, where the name of each element matches a formal argument of solver.method. For example, if a logistic regression using glm is desired,

solver.method = ``glm"

solver.args = list(``family"=binomial)

A solver.method can takes formal arguments 'formula' and 'data' as inputs, such as lm and glm. Some R methods do not use formal names 'formula' and 'data'; a user can indicate if a different naming convention is used for these two input arguments. For example, if a method expects the formula object to be passed through input variable x, solver.args <- list("x"="formula")

A solver.method can also take formal arguments 'x' and 'y' as inputs, such as glmnet. Some R methods do not use formal names 'x' and 'y' to indicate the covariate and response; a user can indicate if a different naming convention is used for these two input arguments. For example, if a method expects the covariate matrix to be passed through input variable X, solver.args <- list("X"="x")

predict.method

A character. The name of the R function or the function to be used to obtain predictions. For example, ‘predict.lm’, ‘predict’, or ‘predict.glm’. If no function is explicitly given, the generic predict is assumed. For many methods, the generic method is appropriate.

predict.args

A list. Additional arguments to be sent to predict.method. This must be provided as a list, where the name of each element matches a formal argument of predict.method. For example, if a logistic regression using glm was used to fit the model formula object and predictions on the scale of the response are desired,

predict.method = ``predict.glm"

predict.args = list(``type"=``response").

It is assumed that the predict.method has formal arguments “object" and “newdata". If predict.method does not use these formal arguments, predict.args must explicitly indicate the variable names used for these inputs. For example, list(“newx"=“newdata") if the new data is passed to predict.method through input argument “newx".

Details

Unless changed by the user in solver.args and/or predict.args, default settings are assumed for the specified regression and prediction methods.

Value

An object of type modelObj, which contains a complete description of the model, the method to be used for parameter estimates, and the prediction method.

Examples

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    #----------------------------------------------------#
    # Create modeling object using a formula
    #----------------------------------------------------#
    mo <- buildModelObj(model=Y ~ X1 + X2 + X3 + X4,
                        solver.method='lm', 
                        predict.method='predict.lm',
                        predict.args=list(type='response'))

modelObj documentation built on May 29, 2017, 5:56 p.m.