[R] Sum weights of independent variables across models (AIC)

[Michael Just]

Hello,
I'd like to sum the weights of each independent variable across linear
models that have been evaluated using AIC.

For example:

> library(MuMIn)
> data(Cement)
> lm1  <-  lm(y  ~  .,  data  =  Cement)
> dd  <-  dredge(lm1,  beta  = TRUE,  eval  =  TRUE,  rank  =  "AICc")
> get.models(dd, subset = delta <4)

There are 5 models with a Delta AIC Score of less than 4.  I would
like to sum the weights for each of the independent variables across
the five models.

How can I do that?

Thanks,
Mike