On Mon, 22 Aug 2011, Gaspar Reyes Póndigo wrote:
Hi, Dear Grass-stats users
I am new user R 2.13 (spgrass6) from GRASS-GIS 6.4.1-5, under Mac OS X
10.68. I have the following problem, when preparing the data before run
R's princomp() function in R from GRASS, there was an error. The line of
code is copied below:
Please only post to one list at a time, and wait patiently for an answer.
#########################################
library(spgrass6)
G <- gmeta6()
ATC <-
readRAST6(c('Acrf_1993_b1','Acrf_1993_b2','Acrf_1993_b3','Acrf_1993_b4','Acrf_1993_b5','Acrf_1993_b7'))
ATC.nas <- which(is.na(ATC@data$Acrf_1993_b1) & is.na(ATC@data$Acrf_1993_b2) &
is.na(ATC@data$Acrf_1993_b3) & is.na(ATC@data$Acrf_1993_b4) & is.na(ATC@data$Acrf_1993_b5)
& is.na(ATC@data$Acrf_1993_b7))
Never access columns with ...@data$... which is exactly the same as
...$...
ATC.ms.values <- which(!is.na(ATC@data$Acrf_1993_b1) & !is.na(ATC@data$Acrf_1993_b2) &
!is.na(ATC@data$Acrf_1993_b3) & !is.na(ATC@data$Acrf_1993_b4) & !is.na(ATC@data$Acrf_1993_b5)
& !is.na(ATC@data$Acrf_1993_b7))
#######################################
#### I got the following error message
#######################################
ATC.ms.nonas <- ATC.ms.values@data[ATC.ms.values, ]
str(ATC.ms.values) is certainly integer. I believe that you want to say
either (may need casting to SpatialPixelsDataFrame first):
ATC.ms.nonas <- ATC[ATC.ms.values,]
or
ATC.ms.nonas <- as(ATC, "data.frame")[ATC.ms.values,]
Error: tentativa de obtener un slot "data" de un objeto de una clase
básica ("integer") sin slots
which is very clear. Do use str() or class() to check the objects you are
using.
Roger
#########################################
Can you please point my problem? and How do I fix my problem?
Thanks in advance for any help.
NOTE:I followed the guide of
http://grass.osgeo.org/wiki/Principal_Components_Analysis #
Using_R.27s_princomp.28.29_function for PRINCOMP() function.
NOTE: the images are LANDSAT 5 TM
Gaspar Reyes Póndigo
Universidad del Mar, Oaxaca, México
Campus Puerto-Ángel
Carretera principal Puerto Ángel Zipolite km 1.5
C.P. 70902_______________________________________________
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--
Roger Bivand
Department of Economics, NHH Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: [email protected]
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