Displaying 20 results from an estimated 3000 matches similar to: "Plan to build Package to use GRASS from R"
2012 Feb 20
1
readVECT6 and readRAST6 fails with R and GRASS 7 ???
Hello all,
I'm having troubles getting R to load data from GRASS 7. I suspect I have
installed something wrong, but can't figure out what. Any suggestions for
what I could look for or how to trouble shoot this? Thanks in advance for
any help!
After having other issues last week, we have upgraded Debian to the testing
version. The other problems are solved, but now I can't get
2004 Oct 27
1
Problems installing GRASS package
Hi,
I'm running R 2.0 installed from the source port on FreeBSd 4.10
and I'm having trouble installing the GRASS package. Following is the
procedure plus errors:
> options(CRAN="http://cran.us.r-project.org")
> install.packages("GRASS")
<download snipped>
downloaded 186Kb
* Installing *source* package 'GRASS' ...
** libs
cc
2008 Dec 10
2
exporting rast from R to GRASS
Hi, everybody!
i created a imagem by kriging using geoR package. I imported points
from GRASS("zn", after converted to geodata "zn_geo"), the border
"zn_border" and a raster mask. Then i interpolated the points by
kriging and created a raster image. Now, i need export this image back
to GRASS to use it in the module r.mapcalc. I can't do it. I tried use
2003 Jan 10
1
GRASS/R interface problem
Hi all,
In my version of the R package GRASS (pre-4) I only manage to export an R
object to GRASS with the name "akspl" which, if I am not wrong, is only a
sample name in the example(). It goes that way:
rast.obj->akspl
rast.put(G, akspl, lname="rast.obj", ...)
Is that a known problem or have I done something wrong anywhere?
Miha Staut
2007 Jun 13
1
installing GRASS-R packages
Hi,
I tried to install R packages required for the GRASS-R interface by
using the following command (copied from
http://www.geog.uni-hannover.de/grass/statsgrass/grass6_r_install.html):
/install.packages (c("sp", "spgrass6","rgdal","maptools"), dependencies
=TRUE)/
rgdal package was installed successfully;
There were problems to find 'sp' and
2009 Jun 11
1
GRASS raster data processing
Hi,
I just imported two raster maps into R using the SPGRASS6 package, one
containing elevation data and the other containing an erosion index:
Kar_inc <-readRAST6("Incis_Kar", plugin=FALSE)
Kar_dem <- readRAST6("DEM_Kar", plugin=FALSE)
I just wanted to make a xy plot of erosion parameter vs elevation. How does
this work? I don't get how to handle
2003 Oct 13
1
NA's from GRASS-package
Hello,
I run R inside GRASS and tried to obtain values of a raster file inside GRASS
but this raster image contains only a few relevant pixel and approx. 1.5
Mill. NA's, I did
G <- gmeta()
sites1 <- rast.get(G, "sites1")
df.sites1 <- data.frame(east(G), north(G), sites1, na.action=na.omit)
Error in as.data.frame.default(x[[i]], optional = TRUE) :
can't
2005 Feb 08
1
Using GRASS/R interface with an xy location
I am using GRASS 5.7 and R 2.0 for OS X. I have a simple xy location I
am doing some theoretical work with and would like to import maps into
R using the interface in order to do analyses. Yet when I attempt to
do this, I get the following error:
>G<-gmeta()
Error in gmeta() : region for current mapset is invalid
line 11: <top: 100>
run "g.region"
I traced the
2012 Apr 20
2
a blade of grass cracks the sidewalk
spring has sprung, so on this day of grass,
i guess i just can't hold this back any more.
> http://zenmagiclove.com/aarp2.py
voila. a dingus for zen markup language.
lighter than markdown.
_and_ more powerful...
i know. wha? go figure.
not that it's a competition.
supporters will love finally seeing a look.
detractors will love the bugs i left in there,
just for them, as
2008 Aug 01
1
bug in readRAST6 function in package spgrass6
Hi
if I try to import a raster layer which consists only of NULL values
from grass by using the readRAST6, I get an error message:
> readRAST6("HSericea_seedsDisperse_2007")
ERROR: Invalid value for null (integers only)
Error in readBinGrid(rtmpfl11, colname = vname[i], proj4string = p4,
integer = to_int) :
no such file:
2006 Nov 21
3
Fitting mixed-effects models with lme with fixed error term variances
Dear R users,
I am writing to you because I have a few question on how to fix
the error term variances in lme in the hope that you could help me. To
my knowledge, the closest possibility is to fix the var-cov structure,
but not the whole var-cov matrix. I found an old thread (a few years
ago) about this, and it seems that the only alternative is to write the
likelihood down and use optim or a
2018 May 03
4
adding overall constraint in optim()
Hi ?
This is giving me a headache. I?m trying to do a relatively simple optimization ? actually trying to approximate the output from the Excel Solver function but at roughly 1000x the speed. ?
The optimization parameters look like this. The only trouble is that I want to add a constraint that sum(wgt.vect)=1, and I can?t figure out how to do that in optim.
Mo.vect <-
2006 Sep 04
3
Subsetting vectors based on condition
Hello,
I have a question regarding subsetting of vectors. Here's an example of
what I'm trying to do:
vect.1 <- c(76,195, 290, 380)
vect.2 <- c(63, 95, 133, 170, 215, 253, 285, 299, 325, 375)
I would like to subset vect.2 so that it has the same length as vect.1,
and its numbers are the first corresponging higher value compared to
vect.1.
The output should be:
final.output =
2008 Jun 09
1
Cross-validation in R
Folks; I am having a problem with the cv.glm and would appreciate someone
shedding some light here. It seems obvious but I cannot get it. I did read
the manual, but I could not get more insight. This is a database containing
3363 records and I am trying a cross-validation to understand the process.
When using the cv.glm, code below, I get mean of perr1 of 0.2336 and SD of
0.000139. When using a
2012 Dec 11
1
Rprof causing R to crash
I'm trying to use Rprof() to identify bottlenecks and speed up a particullary
slow section of code which reads in a portion of a tif file and compares
each of the values to values of predictors used for model fitting. I've
written up an example that anyone can run. Generally temp would be a
section of a tif read into a data.frame and used later for other processing.
The first portion
2018 May 06
1
adding overall constraint in optim()
Hi Michael,
A few comments
1. To add the constraint sum(wgt.vect=1) you would use the method of
Lagrange multipliers.
What this means is that in addition to the w_i (the components of the
weight variables) you would add an additional variable, call it lambda.
Then you would modify your optim.fun() function to add the term
lambda * (sum(wgt.vect - 1)
2. Are you sure that you have defined
2018 May 03
0
adding overall constraint in optim()
You can't -- at least as I read the docs for ?optim (but I'm pretty
ignorant about this, so maybe there's a way to tweak it so you can).
See here: https://cran.r-project.org/web/views/Optimization.html
for other R optimization capabilities.
Also, given your credentials, the r-sig-finance list might be a
better place for you to post your query.
Cheers,
Bert
Bert Gunter
2018 May 03
2
adding overall constraint in optim()
Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
> On May 3, 2018, at 3:01 PM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
>
> You can't -- at least as I read the docs for ?optim (but I'm pretty
> ignorant
2018 May 04
0
adding overall constraint in optim()
On Thu, May 3, 2018 at 2:03 PM, Michael Ashton
<m.ashton at enduringinvestments.com> wrote:
> Thanks Bert. But everyone on that forum wants to use finance tools rather than general optimization stuff! And I am not optimizing a traditional Markowitz mean-variance problem. Plus, smarter people here. :-)
>
I'm very confused by these statements. Most of the "finance tools"
1999 Sep 02
1
count of factors
Hello,
I was used to count how many times every factor is found the following
way :
(assuming 'vect' is a vector of factors)
tapply(vect,vect,length)
but recently I experienced weird results with this
In fact, my command line was
tapply(ORGMORE[[1]][vect],ORGMORE[[1]][vect],length)
where
- 'vect' is a vector of indices
- 'ORGMORE[[1]]' is a slightly long vector of