[R] Convert list of lists <--> data frame

[Michael Friendly]

For a function that takes an argument as a list of lists of parameters, 
I'd like to be able to convert that
to a data.frame and vice versa, but can't quite figure out how.

pats <- list(structure(list(shape = 0, shape.col = "black", shape.lty = 1,
    cell.fill = "white", back.fill = "white", label = 1, label.size = 1,
    ref.col = "gray80", ref.grid = "yes", scale.max = 100), .Names = 
c("shape",
"shape.col", "shape.lty", "cell.fill", "back.fill", "label",
"label.size", "ref.col", "ref.grid", "scale.max")), structure(list(
    shape = 0, shape.col = "black", shape.lty = 1, cell.fill = "pink",
    back.fill = "white", label = 1, label.size = 1, ref.col = "gray80",
    ref.grid = "yes", scale.max = 100), .Names = c("shape", "shape.col",
"shape.lty", "cell.fill", "back.fill", "label", "label.size",
"ref.col", "ref.grid", "scale.max")), structure(list(shape = 0,
    shape.col = "black", shape.lty = 1, cell.fill = "red", back.fill = 
"white",
    label = 1, label.size = 1, ref.col = "gray80", ref.grid = "yes",
    scale.max = 100), .Names = c("shape", "shape.col", "shape.lty",
"cell.fill", "back.fill", "label", "label.size", "ref.col", "ref.grid",
"scale.max")))

So, I want pats.df to have 10 columns,
c("shape",  "shape.col", "shape.lty", "cell.fill", "back.fill", "label",
"label.size", "ref.col", "ref.grid", "scale.max"), and 3 rows for this 
example.

Given pats.df, I'd want to turn that back to pats.

thanks for any help,
-Michael

-- 
Michael Friendly     Email: friendly AT yorku DOT ca 
Professor, Psychology Dept.
York University      Voice: 416 736-5115 x66249 Fax: 416 736-5814
4700 Keele Street    http://www.math.yorku.ca/SCS/friendly.html
Toronto, ONT  M3J 1P3 CANADA