Image Plot for Response Surface Fit

DESCRIPTION:

Makes a image plot based on a response surface fit.

USAGE:

image.rsm.lm(rsm.object, vary, granularity = 50, add = F,  
             legend = T, ... ) 

REQUIRED ARGUMENTS:

rsm.object
the output from fitting a response surface using rsm.lm.

OPTIONAL ARGUMENTS:

vary
a list, with components named by the factors in rsm.object, that determines which two factors are varied on the x and y axes while the remaining factors are held constant. The components corresponding to the factors to be varied are assigned the value "v", while the remaining components are assigned either an explicit numeric value or the value "c" to indicate that the factor is to be held constant at its center point. (If a variable is omitted from the list, "c" is assumed.) By default, the first two factors in rsm.object are varied.
granularity
integer length of the vectors containing the x and y coordinates of the grid over which the response is evaluated.
add
logical indicating whether to add the image to the current plot.
legend
logical indicating whether to construct a legend on the plot.
...
other arguments passed to image.default. This function is a method for the generic function for class `rsm.lm'. It can be invoked by calling for an object x of the appropriate class, or directly by calling regardless of the class of the object.

SIDE EFFECTS:

a image plot is drawn on the current device.

SEE ALSO:

, , , , .

EXAMPLES:

ab.rsm <- rsm.lm(abrsm.df) 
image(ab.rsm) 
image(ab.rsm, vary = list(RadDos = "v", Prime1 = "v"))