mFit: Interactive applet for term selection and nonlinear...

In mosaicManip: Project MOSAIC (mosaic-web.org) manipulate examples.

Description

Displays data and a menu of modeling functions. Finds a linear combination of the selected modeling functions, with the user setting nonlinear parameters manually.

Usage

mFit(expr, data, instructor=rep(TRUE, 13), ...)

Arguments

expr	A formula object giving the dependent and independent variables to use.
data	A data frame containing the values for the variables identified in expr.
instructor	A logical vector consisting of TRUE and FALSE that tells the program which checkboxes to display. The vector is length 13. The order of terms to which instructor corresponds is as follows: 1. constant 2. x 3. $x^2$ 4. $x^3$ 5. log(x) 6. exp(k*x) 7. pnorm1 8. pnorm2 9. pnorm3 10. pnorm4 11. pnorm5 12. sin(x) 13. cos(x)
...	Extra arguments to be passed to the functions described in instructor. Mostly these will not be evaluated.

Details

This function attempts to fit a linear combination of the selected terms to the data plotted. Terms are selected by clicking the corresponding checkbox. There are sliders only for nonlinear parameters. Linear coefficients are found automatically. Only a function of one variable is supported at present. By checking each checkbox, the term is added to the fitted function, and the linear fit of the selected terms is updated. The instructor argument allows an instructor to hide certain terms such that a lesson may be geared towards specific subjects without distraction. mFitSines, mFitSigmoidal, and mFitPoly are premade wrappers that select only the constant, x, and sines and cosines terms, the pnorm terms, and the polynomial terms, respectively.

Value

A function that implements the current state of the parameters and terms selected.

Author(s)

Andrew Rich ([e-mail]) and Daniel Kaplan ([e-mail])

Examples

	if(require(manipulate)){
		data(KidsFeet)
		mFit(width ~ length, data=KidsFeet)
	}

mosaicManip documentation built on May 2, 2019, 5:48 p.m.