On Mon, 6 Apr 2009, Steve Murray wrote:
Dear R Users,
I have 120 data frames of the format table_198601, table_198602...
table_198612, table_198701, table_198702... table_198712 through to
table_199512 (ie. the first 4 digits are years which vary from 1986 to
1995, and the final two digits are months which vary from 01 to 12 for
each year).
I simply hope to find the means of column 3 of each of the 120 tables
without having to type out mean(table_198601[3]) etc etc each time. How
would I go about doing this? And how would I go about finding the mean
of all the January months (01) from say 1986 to 1990?
Put all the tables in a list, then you can iterate over them, eg
lapply(the_list, function(table) mean(table[,3))
You might also want a list of lists to maintain the annual structure, so
that
januaries <- lapply(list_list, function(year) mean(year[[1]][,3]))
-thomas
Finally, I hope to be able to plot (as a scatter graph) the values of
column 1 against the mean of those from column 3 for all the months in
the period 1989 to 1990 and then 1991 to 1995.
Any help offered would be very much appreciated.
Thanks,
Steve
_________________________________________________________________
[[elided Hotmail spam]]
______________________________________________
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
and provide commented, minimal, self-contained, reproducible code.
Thomas Lumley Assoc. Professor, Biostatistics
tlum...@u.washington.edu University of Washington, Seattle
______________________________________________
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
and provide commented, minimal, self-contained, reproducible code.
