R help - Jun 2009 - getting elements out of list automatically

o <- (structure(list(sand.silt = structure(list(statistic structure(185,
.Names = "W"),
    parameter = NULL, p.value = 0.0478835773838087, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), gravel = structure(list(statistic
structure(249.5, .Names = "W"),
    parameter = NULL, p.value = 0.528568586705971, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), cobble = structure(list(statistic structure(340,
.Names = "W"),
    parameter = NULL, p.value = 0.195229999724195, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), boulder.bedrock = structure(list(statistic
structure(368, .Names = "W"),
    parameter = NULL, p.value = 0.0193433582385429, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), fine.root = structure(list(statistic
structure(395.5, .Names = "W"),
    parameter = NULL, p.value = 0.0147991488721795, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), course.root = structure(list(statistic
structure(244.5, .Names = "W"),
    parameter = NULL, p.value = 0.202661704288995, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), wood = structure(list(statistic structure(289.5,
.Names = "W"),
    parameter = NULL, p.value = 0.82819937730819, null.value structure(0, .Names
= "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), leaf = structure(list(statistic = structure(257,
.Names = "W"),
    parameter = NULL, p.value = 0.566029791094808, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), leaf.sand = structure(list(statistic
structure(194, .Names = "W"),
    parameter = NULL, p.value = 0.0149634957806214, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), veg = structure(list(statistic = structure(399.5,
.Names = "W"),
    parameter = NULL, p.value = 0.0091447786580201, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest"), pool = structure(list(statistic = structure(273,
.Names = "W"),
    parameter = NULL, p.value = 0.776755854519814, null.value structure(0,
.Names = "location shift"),
    alternative = "two.sided", method = "Wilcoxon rank sum test
with
continuity correction",
    data.name = ".column by site"), .Names = c("statistic",
"parameter",
"p.value", "null.value", "alternative",
"method", "data.name"
), class = "htest")), .Names = c("sand.silt",
"gravel", "cobble",
"boulder.bedrock", "fine.root", "course.root",
"wood", "leaf",
"leaf.sand", "veg", "pool")))


I know that I can get the elements of this list that I want by

test <- rbind(c(o$veg$p.value, o$veg$statistic), c(o$pool$p.value,
o$pool$statistic))
colnames(test) <- c("p.value", "W")

is there any way to automate this process
-- 
Stephen Sefick

Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods.  We are mammals, and have not exhausted the
annoying little problems of being mammals.

								-K. Mullis

Is this what you want:
> x <- lapply(o, function(z) c(P.value=z$p.value, W=z$statistic))
> do.call(rbind,x)
                    P.value   W.W
sand.silt       0.047883577 185.0
gravel          0.528568587 249.5
cobble          0.195230000 340.0
boulder.bedrock 0.019343358 368.0
fine.root       0.014799149 395.5
course.root     0.202661704 244.5
wood            0.828199377 289.5
leaf            0.566029791 257.0
leaf.sand       0.014963496 194.0
veg             0.009144779 399.5
pool            0.776755855 273.0


On Tue, Jun 2, 2009 at 3:57 PM, stephen sefick <ssefick@gmail.com> wrote:
> o <- (structure(list(sand.silt = structure(list(statistic >
structure(185, .Names = "W"),
>    parameter = NULL, p.value = 0.0478835773838087, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), gravel = structure(list(statistic >
structure(249.5, .Names = "W"),
>    parameter = NULL, p.value = 0.528568586705971, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), cobble = structure(list(statistic >
structure(340, .Names = "W"),
>    parameter = NULL, p.value = 0.195229999724195, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), boulder.bedrock = structure(list(statistic
> structure(368, .Names = "W"),
>    parameter = NULL, p.value = 0.0193433582385429, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), fine.root = structure(list(statistic >
structure(395.5, .Names = "W"),
>    parameter = NULL, p.value = 0.0147991488721795, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), course.root = structure(list(statistic >
structure(244.5, .Names = "W"),
>    parameter = NULL, p.value = 0.202661704288995, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), wood = structure(list(statistic >
structure(289.5, .Names = "W"),
>    parameter = NULL, p.value = 0.82819937730819, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), leaf = structure(list(statistic =
structure(257,
> .Names = "W"),
>    parameter = NULL, p.value = 0.566029791094808, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), leaf.sand = structure(list(statistic >
structure(194, .Names = "W"),
>    parameter = NULL, p.value = 0.0149634957806214, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), veg = structure(list(statistic =
structure(399.5,
> .Names = "W"),
>    parameter = NULL, p.value = 0.0091447786580201, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest"), pool = structure(list(statistic =
structure(273,
> .Names = "W"),
>    parameter = NULL, p.value = 0.776755854519814, null.value >
structure(0, .Names = "location shift"),
>    alternative = "two.sided", method = "Wilcoxon rank sum
test with
> continuity correction",
>    data.name = ".column by site"), .Names =
c("statistic", "parameter",
> "p.value", "null.value", "alternative",
"method", "data.name"
> ), class = "htest")), .Names = c("sand.silt",
"gravel", "cobble",
> "boulder.bedrock", "fine.root",
"course.root", "wood", "leaf",
> "leaf.sand", "veg", "pool")))
>
>
> I know that I can get the elements of this list that I want by
>
> test <- rbind(c(o$veg$p.value, o$veg$statistic), c(o$pool$p.value,
> o$pool$statistic))
> colnames(test) <- c("p.value", "W")
>
> is there any way to automate this process
> --
> Stephen Sefick
>
> Let's not spend our time and resources thinking about things that are
> so little or so large that all they really do for us is puff us up and
> make us feel like gods.  We are mammals, and have not exhausted the
> annoying little problems of being mammals.
>
>                                                                -K. Mullis
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
>
http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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