what are exactly "some operations"? if you could provide a
reproducible code, it would make it easier to understand what you're
trying to achieve.
for example, if you were to get the means, you could do something like:
theMeans <- rapply(test, mean)
cheers,
b
On Aug 11, 2009, at 8:59 PM, Bryan Hanson wrote:
Thanks Henrique. I would have not thought of the syntax you
suggest, though
it embodies the sort of multilevel (not quite recursive) application
of
lapply I was thinking of. However, it returns “test” with V2 missing,
everything else intact. Strange; I can't really state in words what
I think
it should do, much less what it does do!
I think an easier approach for me will be to re-write the function
that
generates "test" so it is simpler to extract what I need. I will
think on
it.
Thanks, Bryan
temp <- lapply(test, lapply, '[', 'V1')
str(temp)
List of 2
$ G:List of 4
..$ cls:'data.frame': 101 obs. of 1 variable:
.. ..$ V1: num [1:101] -0.0019 -0.0019 -0.00189 -0.00188 -0.00186 ...
..$ rob:'data.frame': 101 obs. of 1 variable:
.. ..$ V1: num [1:101] -0.00142 -0.00141 -0.0014 -0.00139
-0.00137 ...
..$ c : num NA
..$ r : num NA
$ T:List of 4
..$ cls:'data.frame': 101 obs. of 1 variable:
.. ..$ V1: num [1:101] -0.00222 -0.00222 -0.00221 -0.00219
-0.00216 ...
..$ rob:'data.frame': 101 obs. of 1 variable:
.. ..$ V1: num [1:101] -0.000981 -0.000979 -0.000972 -0.000961
-0.000946
..
..$ c : num NA
..$ r : num NA
On 8/11/09 7:28 PM, "Henrique Dallazuanna" <[email protected]> wrote:
If I understand correctly your question, you can try something
about like
this:
# Access all elements named 'V1' in your list
lapply(test, lapply, '[', 'V1')
On Tue, Aug 11, 2009 at 3:49 PM, Bryan Hanson <[email protected]>
wrote:
Hello Again R Folks:
I’m trying to clean up some code. Suppose I have an object like
this:
str(test)
List of 2
$ G:List of 2
..$ cls:'data.frame': 101 obs. of 2 variables:
.. ..$ V1: num [1:101] -0.0019 -0.0019 -0.00189 -0.00188
-0.00186 ...
.. ..$ V2: num [1:101] 0.000206 0.000247 0.000288 0.000329
0.000371 ...
..$ rob:'data.frame': 101 obs. of 2 variables:
.. ..$ V1: num [1:101] -0.00142 -0.00141 -0.0014 -0.00139
-0.00137 ...
.. ..$ V2: num [1:101] 0.000424 0.000456 0.000487 0.000517
0.000546 ...
$ T:List of 2
..$ cls:'data.frame': 101 obs. of 2 variables:
.. ..$ V1: num [1:101] -0.00222 -0.00222 -0.00221 -0.00219
-0.00216 ...
.. ..$ V2: num [1:101] -0.00077 -0.000742 -0.000712 -0.000681
-0.000648
..
..$ rob:'data.frame': 101 obs. of 2 variables:
.. ..$ V1: num [1:101] -0.000981 -0.000979 -0.000972 -0.000961
-0.000946
..
.. ..$ V2: num [1:101] -0.000332 -0.000303 -0.000274 -0.000245
-0.000216
..
I need to perform some operations on each value of V1 in turn,
then each
value of V2 in turn (so for instance I want test$G$cls$V1). The
structure
of this object is nearly constant except the first elements of the
list (G,
T in the example) may vary in number and name, so I need something
that
accommodates this.
I can do this with loops, but it seems like a job for lapply or
rapply, but
these don't quite work. I've played with quite a few variations,
searched
the help archives and found a number of useful ideas, but not
quite what I
need. The only thing that nearly works is do.call(cbind, object)
enough
times to bring V1 and V2 "to the surface" but then I've lost my
carefully
constructed naming.
Any suggestions appreciated. It seems like there might be a simple
approach, but I may be too tired right now to see it!
Thanks, Bryan
*************
Bryan Hanson
Professor of Chemistry & Biochemistry
DePauw University, Greencastle IN USA
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
[email protected] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
