rstool (Statistics Toolbox)

Interactive fitting and visualization of a response surface.

Syntax

rstool(x,y)
rstool(x,y,'model')
rstool(x,y,'model',alpha,'xname','yname')

Description

rstool(x,y) displays an interactive prediction plot with 95% global confidence intervales. This plot results from a multiple regression of (X,y) data using a linear additive model.

rstool(x,y,'model') allows control over the initial regression model. 'model' can be one of the following strings:

'interaction' - includes constant, linear, and cross product terms.
'quadratic' - interactions plus squared terms.
'purequadratic' - includes constant, linear and squared terms.

rstool(x,y,'model',alpha) plots 100(1 - alpha)% global confidence interval for predictions as two red curves. For example, alpha = 0.01 gives 99% confidence intervals.

rstool displays a "vector" of plots, one for each column of the matrix of inputs, x. The response variable, y, is a column vector that matches the number of rows in x.

rstool(x,y,'model',alpha,'xname','yname') labels the graph using the string matrix 'xname' for the labels to the x-axes and the string, 'yname', to label the y-axis common to all the plots.

Drag the dotted white reference line and watch the predicted values update simultaneously. Alternatively, you can get a specific prediction by typing the value of x into an editable text field. Use the pop-up menu labeled Model to interactively change the model. Use the pop-up menu labeled Export to move specified variables to the base workspace.

Example

See "Quadratic Response Surface Models" in the manual.