One more question:
Please kindly explain
why it is written as "row.names = c(NA, -11L))."
(in the code below)
I am unsure why it is "negative" 11.
Thank you .
Elaine
code
dta <- structure(list(Species = structure(1:11, .Label = c("Butterfly A1",
+ "Butterfly A2", "Butterfly A3", "Butterfly A4", "Butterfly B1",
+ "Butterfly B2", "Butterfly B3", "Butterfly B4", "Butterfly B5",
+ "Butterfly C1", "Butterfly C2"), class = "factor"), Range = c(130.5,
+ 450.68, 1102.38, 893.34, 820.2, 872.2, 488.2, 620.11, 982.78,
+ 720.32, 912.2), Latitude = c(9.45, 10.2, 9.3, 16.4, 10.54, 10.87,
+ 16.79, 18.3, 12.98, 12.67, 18.07)), .Names = c("Species", "Range",
+ "Latitude"), class = "data.frame", row.names = c(NA, -11L)))
>> >>
>> >>
>> >> ----- Original Message -----
>> >> From: David L Carlson <dcarl...@tamu.edu>
>> >> To: 'Elaine Kuo' <elaine.kuo...@gmail.com>; r-help@r-project.org;
>> >> 'r-sig-geo' <r-sig-...@stat.math.ethz.ch>
>> >> Cc:
>> >> Sent: Sunday, December 16, 2012 11:32 AM
>> >> Subject: Re: [R] averaging X of specific Y (latitude)
>> >>
>> >> It is better to use dput() in R to create a text version of your data
>> for
>> >> us
>> >> to work with. The aggregate command below gives you the mean ranges by
>> >> butterfly species and latititude and saves the result as Bfly. The
>> >> colnames() command simply renames the columns:
>> >>
>> >>> dta <- structure(list(Species = structure(1:11, .Label = c("Butterfly
>> >> A1",
>> >>
>> >> + "Butterfly A2", "Butterfly A3", "Butterfly A4", "Butterfly B1",
>> >> + "Butterfly B2", "Butterfly B3", "Butterfly B4", "Butterfly B5",
>> >> + "Butterfly C1", "Butterfly C2"), class = "factor"), Range = c(130.5,
>> >> + 450.68, 1102.38, 893.34, 820.2, 872.2, 488.2, 620.11, 982.78,
>> >> + 720.32, 912.2), Latitude = c(9.45, 10.2, 9.3, 16.4, 10.54, 10.87,
>> >> + 16.79, 18.3, 12.98, 12.67, 18.07)), .Names = c("Species", "Range",
>> >> + "Latitude"), class = "data.frame", row.names = c(NA, -11L))
>> >>> Bfly <- aggregate(Range~Species+floor(Latitude), dta, mean)
>> >>> colnames(Bfly) <- c("Species", "Latitude", "Mean")
>> >>> Bfly
>> >> Species Latitude Mean
>> >> 1 Butterfly A1 9 130.50
>> >> 2 Butterfly A3 9 1102.38
>> >> 3 Butterfly A2 10 450.68
>> >> 4 Butterfly B1 10 820.20
>> >> 5 Butterfly B2 10 872.20
>> >> 6 Butterfly B5 12 982.78
>> >> 7 Butterfly C1 12 720.32
>> >> 8 Butterfly A4 16 893.34
>> >> 9 Butterfly B3 16 488.20
>> >> 10 Butterfly B4 18 620.11
>> >> 11 Butterfly C2 18 912.20
>> >>
>> >> ----------------------------------------------
>> >> David L Carlson
>> >> Associate Professor of Anthropology
>> >> Texas A&M University
>> >> College Station, TX 77843-4352
>> >>
>> >>> -----Original Message-----
>> >>> From: r-help-boun...@r-project.org [mailto:r-help-bounces@r-
>> >>> project.org] On Behalf Of Elaine Kuo
>> >>> Sent: Saturday, December 15, 2012 10:15 PM
>> >>> To: r-help@r-project.org; r-sig-geo
>> >>> Subject: [R] averaging X of specific Y (latitude)
>> >>>
>> >>> Hello
>> >>>
>> >>>
>> >>>
>> >>> I have a table describing butterfly range traits.
>> >>>
>> >>> It is composed of three columns as below
>> >>>
>> >>>
>> >>>
>> >>> Species name range size (X) latitude of range midpoint (Y)
>> >>>
>> >>>
>> >>>
>> >>> There are 11 kinds of butterflies.
>> >>>
>> >>> Each has its range size, and the latitude of each range midpoint
>> ranges
>> >>> from 9 to 19.
>> >>>
>> >>> I would like to have the average range size of every degree of
>> >>> latitude.
>> >>>
>> >>> For example, the average range size of latitude degree 10 (10.0-10.99:
>> >>> Butterfly A2, B1, B2)
>> >>>
>> >>> Please kindly help with R code to calculate the average values.
>> >>>
>> >>> Thank you.
>> >>>
>> >>>
>> >>> Elaine
>> >>>
>> >>>
>> >>> The details are as followed.
>> >>>
>> >>>
>> >>>
>> >>> Butterfly A1 130.5 9.45
>> >>>
>> >>> Butterfly A2 450.68 10.2
>> >>>
>> >>> Butterfly A3 1102.38 9.3
>> >>>
>> >>> Butterfly A4 893.34 16.4
>> >>>
>> >>> Butterfly B1 820.2 10.54
>> >>>
>> >>> Butterfly B2 872.2 10.87
>> >>>
>> >>> Butterfly B3 488.2 16.79
>> >>>
>> >>> Butterfly B4 620.11 18.3
>> >>>
>> >>> Butterfly B5 982.78 12.98
>> >>>
>> >>> Butterfly C1 720.32 12.67
>> >>>
>> >>> Butterfly C2 912.2 18.07
>> >>>
>> >>> [[alternative HTML version deleted]]
>> >>>
>> >>> ______________________________________________
>> >>> 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.
>> >>
>> >> ______________________________________________
>> >> 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.
>> >>
>> >>
>> >>
>> >
>> > [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > 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.
>>
>>
>
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