long 0-360, shift to -180 to 180

-----Original Message-----
From: Michael Loranty [mailto:mloranty at whrc.org]
Sent: Thursday, March 10, 2011 5:59 AM
To: r-sig-geo; Andy Bunn
Subject: Re: [R-sig-Geo] long 0-360, shift to -180 to 180

Hi Andy,

I think the rotate function in the raster package might be what you're
looking for.

Hope things are well with you.

-Mike

dat <- matrix(data = 1:100, nrow=360, ncol = 360)

 > bar <-

raster(dat,xmn=0,xmx=356.25,ymn=-87.159094555863,ymx=87.159094555863,
+              crs="+proj=longlat +datum=WGS84")

 > bar

class       : RasterLayer
filename    :
nrow        : 360
ncol        : 360
ncell       : 129600
min value   : 1
max value   : 100
projection  : +proj=longlat +datum=WGS84
extent      : 0, 356.25, -87.1591, 87.1591  (xmin, xmax, ymin, ymax)
resolution  : 0.9895833, 0.4842172  (x, y)

 > bar2 <- rotate(bar)
 > bar2

class       : RasterLayer
filename    :
nrow        : 360
ncol        : 360
ncell       : 129600
min value   : 1
max value   : 100
projection  : +proj=longlat +datum=WGS84
extent      : -178.125, 178.125, -87.1591, 87.1591  (xmin, xmax, ymin,
ymax)
resolution  : 0.9895833, 0.4842172  (x, y)


On Mar 10, 2011, at 6:00 AM, r-sig-geo-request at r-project.org wrote:

Message: 18
Date: Wed, 9 Mar 2011 16:18:17 -0800
From: Andy Bunn <Andy.Bunn at wwu.edu>
To: "r-sig-geo at r-project.org" <r-sig-geo at r-project.org>
Subject: [R-sig-Geo] long 0-360, shift to -180 to 180
Message-ID:

	<7E6EA3F4372E474F8F3F850DD262FDA9125D914C82 at ExchMailbox3.univ.dir
.wwu.edu

Content-Type: text/plain; charset="us-ascii"

I have a raster with longitude data over 0 to 360.

bar <- raster(t(foo[,,
1]),xmn=0,xmx=356.25,ymn=-87.159094555863,ymx=87.159094555863,
             crs="+proj=longlat +datum=WGS84")

I'd like to shift those longitudes to -180 to 180. I tried paying
with the +long_wrap argument to crs but to no avail. Can somebody
help? I'll need to overlay and extract data from the negative side
(e.g., 100W or -100) and it would be nice to have the coordinates
the same.

Thanks in advance,
Andy

-----Original Message-----
From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-
project.org] On Behalf Of Tom Gottfried
Sent: Wednesday, March 09, 2011 1:40 PM
To: r-sig-geo at r-project.org
Subject: Re: [R-sig-Geo] predicting values from variofit function

Hi Anna,

Am 09.03.2011 21:25, schrieb Anna Gretschel:

Dear List,

I have fitted a spherical function to my variogram using

"variofit(...)"

from GeoR. Now I would like to predict some data with the function
"predict(object,...)" from package stats.

Note that predict() is a generic function (see
http://cran.r-project.org/doc/manuals/R-intro.html#Object-

orientation)

.
I don't think there is a method in geoR that does what you want.

Does anyone know wether this
works and if it does how to do it?

The package gstat has a method for objects of class gstat (see ?
gstat,
?predict.gstat and the ASDAR book). You can coerce your variogram

fit

from geoR to the respective class used in package gstat with
as.vgm.variomodel(). You can do kriging with krige.conv() from geoR
too.
But I think you have more options in gstat.

regards,
Tom

Thanks a lot!
Anna

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