classIntervals issue
On Thu, 26 May 2011, Carson Farmer wrote:
Hi List, not sure if this is *really* an r-sig-geo question, but since Roger is the maintainer for the classInt package, I thought I'd start here. For some reason, whenever creating a classIntervals object, if I try to print/access said object's "table" attribute for using in a legend (see p. 79 in ASDA with R), I get the following error message:
classIntervals(layer$incoming, n=5, style="fisher", cutlabels=TRUE)
style: fisher
[3,813) [813,2782.5) [2782.5,6365) [6365,12569) [12569,20422]
2993 306 84 20 6
Warning messages:
1: In factorial(n - 1) : value out of range in 'gammafn'
2: In factorial(n - k) : value out of range in 'gammafn'
Can anyone tell me why? For reference, the data that I'm trying to
classify looks like this (nothing too weird that I can see):
summary(layer$incoming)
Min. 1st Qu. Median Mean 3rd Qu. Max. 3.0 43.0 86.0 434.1 263.0 20420.0
Class intervals must be relevant, no? Reproducing:
x <- exp(runif(3409, 0, 10)) summary(x)
Min. 1st Qu. Median Mean 3rd Qu. Max.
1.00 11.48 143.70 2277.00 1776.00 21970.00
cl <- classIntervals(x, n=5, style="fisher", cutlabels=TRUE) cl
style: fisher
[1.000301,1745.2) [1745.2,5520.098) [5520.098,10475.15)
[10475.15,16236.95)
2549 375 217
147
[16236.95,21965.68]
121
Warning messages:
1: In factorial(n - 1) : value out of range in 'gammafn'
2: In factorial(n - k) : value out of range in 'gammafn'
factorial(3409-1)
[1] Inf Warning message: In factorial(3409 - 1) : value out of range in 'gammafn'
factorial(3409-5)
[1] Inf Warning message: In factorial(3409 - 5) : value out of range in 'gammafn'
factorial
function (x) gamma(x + 1) <environment: namespace:base>
gamma(3409)
[1] Inf Warning message: value out of range in 'gammafn'
nPartitions
function (x)
{
n <- attr(x, "nobs")
k <- length(x$brks) - 1
(factorial(n - 1))/(factorial(n - k) * factorial(k - 1))
}
<environment: namespace:classInt>
nPartitions(cl)
[1] NaN Warning messages: 1: In factorial(n - 1) : value out of range in 'gammafn' 2: In factorial(n - k) : value out of range in 'gammafn' This is coming from the code in the print method that shows how many combinations of 3409 objects into 5 classes are possible, which is so large that the calls to factorial() and from there to gamma() fail. I can put in a check for n > 170 to suppress this information, because factorial(n-1) fails just above there. Interesting point! Roger
sessionInfo()
R version 2.13.0 (2011-04-13)
Platform: x86_64-pc-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_IE.utf8 LC_NUMERIC=C
LC_TIME=en_IE.utf8
[4] LC_COLLATE=en_IE.utf8 LC_MONETARY=C
LC_MESSAGES=en_IE.utf8
[7] LC_PAPER=en_IE.utf8 LC_NAME=C LC_ADDRESS=C
[10] LC_TELEPHONE=C LC_MEASUREMENT=en_IE.utf8
LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] lattice_0.19-26 classInt_0.1-14 e1071_1.5-25 class_7.3-3
TeachingDemos_2.7
[6] sp_0.9-80 CircStats_0.2-4 boot_1.2-43 MASS_7.3-13
loaded via a namespace (and not attached):
[1] grid_2.13.0 tools_2.13.0
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no