[R] How to plot 3-D surface graph from lmer mixed models?
jianghua.liu at shef.ac.uk
Thu Aug 13 15:34:48 CEST 2009
Dear Professor Murdoch,
That is exactly the difficulty for me. I don't know how to make a prediction
with lmer using "expand.grid"; at the moment, I can use
“model at X%*%fixef(model)” to get predicted values for existing observational
data, but not data by "expand.grid". Actually, if I know this, I can then
use "persp" or "wireframe" to plot 3-D surface graph. Do you know or have
available code for this aim?
Sorry, this request must sound very lazy or stupid.
Thank you very much for helping!
Duncan Murdoch-2 wrote:
> I only see two explanatory variables: afr_c, byear_c. If you have more
> than two, you can't use a surface plot: surfaces are two dimensional.
> All of the 3D surface functions want basically the same thing: a matrix
> giving evaluations of a function at locations of the explanatory
> variables. So you need to calculate that. I'd do it by using
> expand.grid to create a large set of combinations of values of the
> explanatory variables, ask your model to do predictions at all of those
> locations, and then reshape the result into a matrix.
> Duncan Murdoch
> R-help at r-project.org mailing list
> PLEASE do read the posting guide
> and provide commented, minimal, self-contained, reproducible code.
View this message in context: http://www.nabble.com/How-to-plot-3-D-surface-graph-from-lmer-mixed-models--tp24952273p24954438.html
Sent from the R help mailing list archive at Nabble.com.
More information about the R-help