[R] logistic regression 3D-plot

[heikz@gmx.de]

Dear R-helpers,

I tried to create a 3D surface showing the interaction between two
continuous explanatory variables; the response variable is binary (0/1).

The model is:

model<-glm(incidence~sun*trees,binomial)

then I used "wireframe" to create a 3D plot:

xyz<-expand.grid(sun=seq(30,180,1),trees=seq(0,4000,10))

xyz$incidence<-as.vector(predict(model,xyz))

wireframe(incidence~sun*trees,xyz,scales=list(arrows=FALSE))

which gives me a 3D plot, but the scaling of the y-axis is wrong. the range
is not from 0 to 1.
so my question: is there a way to plot these kind of models, with binary
response variables?

thanks for your help, Heike


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