[R] YALAQ - Yet Another LApply Question
Thompson, David (MNR)
David.John.Thompson at ontario.ca
Wed Oct 15 20:04:27 CEST 2008
Thank you very much Greg.
Apparently, my learning curve is still well below it's horizontal
asymptote.
And no wonder in the vast universe of the R-project, eh?
Thanx, DaveT.
>-----Original Message-----
>From: Greg Snow [mailto:Greg.Snow at imail.org]
>Sent: October 15, 2008 01:52 PM
>To: Thompson, David (MNR); r-help at r-project.org
>Subject: RE: YALAQ - Yet Another LApply Question
>
>For the first question, ?str tells us that the str function
>does not return anything, but has a side effect of printing
>information to the console. So in version 1 when you call the
>cat function it evaluates its arguments and as it evaluates
>str(...) the information is printed, then nothing is passed
>into cat which then prints the name of the object (after str
>has done its printing). In the second version cat finishes
>printing the name before str is called so that it is in the
>correct order.
>
>You might prefer to use lapply/sapply to create a list with
>all the pieces of interest, then just do str on the resulting
>list, or look at the TkListView function in the TeachingDemos
>package for another way to look at the structure of a list.
>
>For example:
>
>TkListView( sapply( ls(pattern='bn'), function(y) get(y),
>simplify=FALSE, USE.NAMES=TRUE ) )
>
>
>For the 2nd question, the difference is that the summary
>function does not print anything, just returns the summary
>information. When you type summary at the command line the
>parser automatically calls the print method for the summary
>object returned, but within functions/loops/apply the summary
>object is returned (included in the output of lapply) but not
>printed. You need to explicitly print the results of summary.
>
>Hope this helps,
>
>--
>Gregory (Greg) L. Snow Ph.D.
>Statistical Data Center
>Intermountain Healthcare
>greg.snow at imail.org
>801.408.8111
>
>
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
>> project.org] On Behalf Of Thompson, David (MNR)
>> Sent: Wednesday, October 15, 2008 10:19 AM
>> To: r-help at r-project.org
>> Subject: Re: [R] YALAQ - Yet Another LApply Question
>>
>> Please forgive this repost, it's been a week without a squeak. No
>> comments?
>>
>> Original post:
>> https://stat.ethz.ch/pipermail/r-help/2008-October/176340.html
>> Hello,
>>
>> Two lapply questions (system info and sample data below):
>>
>> 1) Why does the first form of command1 add the name of y _after_ the
>> str() output rather than before as does the second (preferred) form?
>> # command1 version1
>> invisible(lapply(ls(pattern='bn'), function(y) cat(y, "\n",
>> str(get(y)), "\n") ))
>>
>> # command1 version2 (preferred output)
>> invisible(lapply(ls(pattern='bn'), function(y) { cat(y, "\n") ;
>> str(get(y)) ; cat("\n") } ))
>>
>> 2) Why does the same method as command1 version2 above not work with
>> the
>> summary() command as does the second (preferred) set of commands?
>> # command2 version1
>> lapply(ls(pattern='bn'), function(y) { cat(y, "\n") ;
>> summary(get(y))
>> ; cat("\n") } )
>>
>> # command2 version2 (preferred output)
>> smry.list <- lapply(ls(pattern='bn'), function(y) summary(get(y)))
>> names(smry.list) <- ls(pattern='bn')
>> smry.list
>>
>> Thanx, DaveT.
>>
>> ###
>> # system info:
>> > sessionInfo() ; cat("\n") ; Sys.info()[c(1:3,5)]
>> R version 2.7.2 (2008-08-25)
>> i386-pc-mingw32
>>
>> locale:
>>
>LC_COLLATE=English_Canada.1252;LC_CTYPE=English_Canada.1252;LC_MONETARY
>> =
>> English_Canada.1252;LC_NUMERIC=C;LC_TIME=English_Canada.1252
>>
>> attached base packages:
>> [1] stats graphics grDevices datasets tcltk utils
> methods
>> base
>>
>> other attached packages:
>> [1] debug_1.1.0 mvbutils_1.1.1 lattice_0.17-14 plotrix_2.4-7
>> svSocket_0.9-5 TinnR_1.0.2 R2HTML_1.59 Hmisc_3.4-3
>>
>> loaded via a namespace (and not attached):
>> [1] cluster_1.11.11 grid_2.7.2 svMisc_0.9-5 tools_2.7.2
>>
>> sysname release
>> version machine
>> "Windows" "XP"
>"build 2600,
>> Service Pack 2" "x86"
>> # system info:
>> ###
>>
>> ###
>> # sample data
>> # dput(ban.nat.1994[sample(row.names(ban.nat.1994), 20),])
>> bn94 <- structure(list(oplt = c(18L, 50L, 11L, 16L, 54L,
>35L, 45L, 40L,
>> 15L, 50L, 38L, 45L, 53L, 15L, 1L, 54L, 33L, 13L, 30L, 21L), tree =
>> c(144L,
>> 824L, 47L, 525L, 291L, 702L, 717L, 615L, 821L, 551L, 750L, 639L,
>> 664L, 813L, 31L, 346L, 689L, 59L, 200L, 658L), bd1 = c(NA, NA,
>> 3.6, 3.1, 4.72, 2.03, 2.88, 1.65, 5.39, 3.04, 2.75, 3.06, 2.81,
>> 2.78, NA, 6.5, 4.62, 4.76, NA, 2.69), bd2 = c(NA, NA, 3.41, 3.06,
>> 4.86, 2.09, 2.78, 1.8, 5.08, 3.26, 2.71, 3.1, 2.87, 2.73, NA,
>> 6.6, 4.53, 4.97, NA, 2.81), bd = c(NA, 4.25, 3.51, 3.08, 4.79,
>> 2.06, 2.83, 1.72, 5.23, 3.15, 2.73, 3.08, 2.84, 2.76, NA, 6.55,
>> 4.58, 4.87, NA, 2.75), ht = c(NA, 20.4, 18.1, 18, 25.8, 13.1,
>> 15.7, 4, 16, 14, 12.7, 8.6, 8.1, 16.2, NA, 52.7, 31.7, 23.7,
>> NA, 17.6), spr = c(NA_integer_, NA_integer_, NA_integer_,
>NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_), stat = c(1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L,
>> 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 1L, 0L), dam = c(NA, 2L, NA,
>> NA, NA, NA, NA, 2L, NA, NA, 2L, NA, 1L, NA, NA, NA, 1L, NA, NA,
>> NA), com = c("", "from partial data set, tend = 1", "", "", "",
>> "", "", "", "", "", "", "", "", "", "", "", "", "", "",
>"")), .Names =
>> c("oplt",
>> "tree", "bd1", "bd2", "bd", "ht", "spr", "stat", "dam", "com"
>> ), row.names = c(1049L, 2845L, 549L, 884L, 3128L, 1887L, 2432L,
>> 2087L, 879L, 2729L, 1990L, 2421L, 3089L, 871L, 3L, 3158L, 1801L,
>> 704L, 1653L, 1215L), class = "data.frame")
>>
>> # dput(ban.nat.1995[sample(row.names(ban.nat.1995), 20),])
>> bn95 <- structure(list(oplt = c(2L, 27L, 54L, 8L, 8L, 51L,
>3L, 4L, 20L,
>> 35L, 15L, 22L, 31L, 7L, 4L, 31L, 34L, 6L, 20L, 51L), tree = c(773L,
>> 308L, 331L, 234L, 235L, 170L, 211L, 701L, 745L, 709L, 798L, 350L,
>> 207L, 736L, 718L, 240L, 193L, 266L, 735L, 244L), bd1 = c(8.41,
>> NA, 6.93, 2.74, 6.06, 2.36, 5.87, 3.53, 2.48, NA, 9, 4.18, 1.74,
>> 3.42, 5.54, 3.74, 3.26, 2.38, 4.42, 3.65), bd2 = c(8.76, NA,
>> 7.17, 2.82, 6.16, 2.33, 6.05, 2.58, 2.5, NA, 9.04, 4.22, 1.68,
>> 3.39, 5.52, 3.68, 3.18, 2.38, 4.47, 3.74), bda = c(8.59, NA,
>> 7.05, 2.78, 6.11, 2.34, 5.96, 3.05, 2.49, NA, 9.02, 4.2, 1.71,
>> 3.41, 5.53, 3.71, 3.22, 2.38, 4.44, 3.7), ht = c(69.2, NA, 55.2,
>> 25.7, 47.8, 17.1, 35.6, 11, 12, NA, 52.5, 33.2, 10.4, 16.2, 32.7,
>> 22.1, 15, 13.6, 24.5, 22.4), spr = c(NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_, NA_integer_, NA_integer_,
>> NA_integer_, NA_integer_, NA_integer_), stat = c(0L, 1L, 0L,
>> 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L,
>> 0L), dam = c(NA, NA, NA, NA, NA, NA, NA, 1L, NA, NA, NA, NA,
>> NA, NA, NA, NA, NA, NA, NA, NA), com = c("", "", "", "", "",
>> "", "", "", "", "", "", "", "", "", "", "", "", "", "",
>"")), .Names =
>> c("oplt",
>> "tree", "bd1", "bd2", "bda", "ht", "spr", "stat", "dam", "com"
>> ), row.names = c(34L, 462L, 724L, 227L, 228L, 673L, 76L, 123L,
>> 368L, 632L, 281L, 391L, 495L, 199L, 140L, 528L, 604L, 191L, 358L,
>> 689L), class = "data.frame")
>>
>> # dput(ban.nat.1996[sample(row.names(ban.nat.1996), 20),])
>> bn96 <- structure(list(oplt = c(23L, 33L, 22L, 19L, 27L, 3L,
>27L, 19L,
>> 48L, 31L, 54L, 37L, 42L, 45L, 51L, 51L, 27L, 44L, 22L, 33L),
>> tree = c(616L, 709L, 426L, 233L, 441L, 213L, 411L, 231L,
>> 714L, 206L, 355L, 638L, 266L, 201L, 345L, 298L, 151L, 374L,
>> 571L, 708L), bd1 = c(4.68, 1.92, 4.89, 4.88, 2.02, 4.2, 2,
>> 2.85, 3.38, 2.48, 3.42, NA, 2.1, 2.05, 1.98, 2.26, NA, 5.16,
>> 2.9, 2.32), bd2 = c(4.7, 1.98, 4.94, 5.14, NA, 3.96, NA,
>> 2.9, 3.2, 2.42, 3.36, NA, 2, 2.02, NA, NA, NA, 5.2, 2.8,
>> 2.24), bd = c(4.69, 1.95, 4.92, 5.01, NA, 4.08, NA, 2.88,
>> 3.29, 2.45, 3.39, NA, 2.05, 2.03, NA, NA, NA, 5.18, 2.85,
>> 2.28), ht = c(31.9, 14.7, 30.7, 24.2, 9.5, 24.3, 8.2, 28.1,
>> 22.5, 10.6, 35.5, NA, 13.3, 9.3, 20.2, 10, NA, 24.7, 18.5,
>> 15.7), spr = c(NA, NA, NA, 2L, NA, NA, NA, NA, NA, NA, NA,
>> NA, NA, NA, NA, NA, NA, NA, NA, NA), stat = c(0L, 0L, 0L,
>> 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 1L, 0L,
>> 0L, 0L), dam = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA,
>> NA, NA, NA, NA, NA, NA, NA, 2L, NA, NA), yrc = c(95L, 95L,
>> 95L, 95L, 93L, 95L, 93L, 95L, 94L, 95L, 95L, 95L, 94L, 96L,
>> 93L, 93L, 95L, NA, 95L, 95L), az = c(NA, 172L, NA, NA, 276L,
>> NA, 243L, NA, 221L, 2L, 80L, 270L, 342L, NA, 240L, 170L,
>> 6L, NA, NA, 155L), dist = c(NA, 11.21, NA, NA, 8.1, NA, 15.94,
>> NA, 9.11, 9.23, 6.39, 6.45, 10.88, NA, 12.42, 15.19, 15.16,
>> NA, NA, 13.52), com = c("", "", "", "", "", "", "", "", "",
>> "", "", "", "", "", "", "", "", "new", "", "")), .Names
>= c("oplt",
>> "tree", "bd1", "bd2", "bd", "ht", "spr", "stat", "dam", "yrc",
>> "az", "dist", "com"), row.names = c(366L, 758L, 335L, 285L, 600L,
>> 61L, 583L, 283L, 1184L, 671L, 1422L, 818L, 930L, 1006L, 1331L,
>> 1299L, 447L, 996L, 343L, 757L), class = "data.frame")
>> # sample data
>> ###
>>
>> *************************************
>> Silviculture Data Analyst
>> Ontario Forest Research Institute
>> Ontario Ministry of Natural Resources
>> david.john.thompson at ontario.ca
>> http://ontario.ca/ofri
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
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>> PLEASE do read the posting guide http://www.R-project.org/posting-
>> guide.html
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>
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