Displaying 20 results from an estimated 3000 matches similar to: "Extracting xy from raster based on raster value"
2010 Jul 28
2
Beginner stucked with raster + geoR package.
Hello everyone.
I am trying to build up understanding in R by trying to develop just some simple
scenarios.
I would like to explain you what I am trying to do and what I did so far.
I would like to put inside a RasterLayer (raster package) a Gaussian field (for
given covariance) using grf function (geoR package)
1. First I created a Raster Layer object
r <- raster() # Default values are
2004 Feb 26
6
adding header info to write.table
Hello,
Could someone please tell if there is a way to append header info to the top of an exported dataframe (exported with write.table). I want to append the following, which are the defininitions for an asciigrid:
ncols 532
nrows 999
xllcorner 510465
yllcorner 4766375
cellsize 30
NODATA_value -9999
Thanks very much,
femke
[[alternative HTML version deleted]]
2011 Jan 31
1
str() on raster objects fails for certain dimensions
Hi,
str() on raster objects fails for certain dimensions. For example:
> str(as.raster(0, nrow=1, ncol=100))
'raster' chr [1, 1:100] "#000000" "#000000" "#000000" "#000000" ...
> str(as.raster(0, nrow=1, ncol=101))
Error in `[.raster`(object, seq_len(max.len)) : subscript out of bounds
This seems to do with how str() and
2004 Feb 17
4
importing ascii grids (for gstat)
Hello,
Is there anyone who could give me an example of how to import an ascii grid (i.e. ArcGIS exported raster) into R. I want to use it with gstat but don't know the appropriate import routine.
Thanks very much for your help.
Regards,
femke
Femke Reitsma
Graduate Student (ABD)
Geography Department
2181 LeFrak Hall
University of Maryland
College Park, MD 20742
Phone: 301-405-4121
2013 Oct 24
1
Plot.raster hides the axis layer
Hi all,
I am trying to plot a raster object (I can explain why but the point is that it would be a raster objeƧt)..
I have selected a small code to show you exactly the problem
require(raster)
test<-matrix(data=runif(10000),nrow=100)
m<-raster(test)
plot(m,axes="FALSE")
axis(1,at=c(0,1),labels=c("a","b")) # THIS DOES NOT CHANGE THE INVISIBLE AXIS WHILE
2011 Dec 01
1
Raster manipulation in R
Hello everyone in the forum
For introducing myself I would say I have a basic knowledge of R.
Now I am intended to implement a flood algorithm using R. I have some MatLab
experience doing these, and as an example to explain more or less what I
want, I have a m code to calculate the slope from a Digital elevation model:
slope=zeros(row,col);
for i=2:row-1
for j=2:col-1
2013 Apr 24
2
How to make a raster image in R from my own data set
Hi R-user,
I was trying to make a raster map with WGS84 projection in R, but I could not make it. I found one data set in Google that data is almost the same format as of mine. I wanted to make a raster map of temperature with 1 degree spatial resolution for the global scale.
I could make it in GIS software but I do have many variables (to be many raster images) and ultimately I am importing them
2010 Jan 16
1
"Too many raster images" in devPS.c
Hi,
I am finding the recently added [1] functionality of embedding raster
images into plots on R devices very useful! Thanks to Paul Murrell and
others for providing that. I noted that in
https://svn.r-project.org/R/trunk/src/library/grDevices/src/devPS.c
a macro is defined: #define MAX_RASTERS 64, and consequently, I get
Error in grid.Call.graphics("L_raster", x$raster, x$x, x$y,
2011 Jun 10
2
merge large number of raster objects
Hello,
I have a large number of raster objects in memory, with names RH100,
RH101, RH102, etc. (myobjects <- ls(pattern='^RH')).
These rasters are sections of a continuous map, and I would like to
combine them using the RasterObject merge tool in package 'raster.'
Merge expects an input list of raster objects (outmap<-merge(x, y, ...),
where x, y, and ... are raster
2013 Jan 29
2
Netcdf and Raster Package Questions, Need .asc File for GIS
Hello R-Group,
I am new working with netcdf files and the raster package in R.I am
trying to read in a netcdf file using the package "ncdf".I am able to
get the lat, lon and parameter I need and can plot using
fill.contour.Ultimately, I am trying to create a .asc file to reafd into
GIS.I am using the package "raster" to read the parameter.When I read in
with
2020 Oct 31
2
raster::levels() not working in packaged function.
Apologies, I cannot see how to make a rero for this issue.
I have a function that uses levels(r) tor return the RAT of a raster "r"
when the function is sourced from a script
source(".\R\function.r")
it works fine.
when the function is built into a package and sourced from there
library(mypackage) using the same script file to make the package
levels(r)[[1]]
the same line
2009 Apr 18
1
install raster package on ubuntu
Dear all,
I am running R 2.8.1. under ubuntu, and I need to install
the package "raster" but I get the following error:
> install.packages("raster")
Warning in install.packages("raster") :
argument 'lib' is missing: using '/usr/local/lib/R/site-library'
--- Please select a CRAN mirror for use in this session ---
Loading Tcl/Tk interface ... done
2012 Oct 29
3
How can I map numbers to colours with raster?
This code will read binary file and display it as a map. may problem is that
this code is using a continuous colour scheme, even though I have discrete
data (which is a classification scheme). How can I map numbers to colours
with raster? Please
require(raster)
conne <- file("C:\\lai.bin", "rb")
sd<- readBin(conne, integer(), size=1, n=360*720, signed=F)
2012 Mar 21
2
To overlay my raster and its boundary
Hi
I want to overlay my raster and its boundary which is a shapefile.
When I used thise code separately, all is ok:
# Open raster
>Image<-read.table("C:\\Users\\Documents\\Nouveau\\Frequence.txt",sep="",dec=",",header=TRUE)
>testo<-rasterFromXYZ(Image)
>plot(testo)
>testo2 <- aggregate(testo,fact=10, fun=mean)
>plot(testo2)
# open
2012 Aug 08
1
Adjusting coordinates in raster plots
Dear R-Help,
When plotting a raster object the origin (0,0) is placed in the center.
E.g. using:
library(raster)
mat = matrix(runif(100),10,10)
r <- raster(ncol=10, nrow=10)
values(r) <- mat
plot(r, main='Raster example',xlab="x",ylab="y")
Does anyone know how to adjust the coordinate system?
E.g. I would like to have 0,0 at the top left.
My naive approach
2012 Nov 27
5
Predict function in Raster package
Hey,
I am having troubles using the 'predict' function with in the Raster
package. I am using pm<-predict(mm, predictors) where mm is the
mahalanobis distance and the predictors are a stack of 6 raster layers
containing environmental variables.
When I try to run the prediction I get the following warning message:
Warning message:
In layerNames(x): the layerNames function is
2012 Jan 25
4
x11() graphic device, displaying raster
Hello,
I am wondering about the X11() graphic device on Windows.
I try to plot a raster image but nothing gets displayed. I
found some pages where it is mentioned that x11() not
always supports raster rendering.
Is there any add on for x11, any update or any R-package
which solves that displaying problem in Windows?
What I try to test it is an example from the
package {raster}:
library(raster)
2012 Jan 25
4
x11() graphic device, displaying raster
Hello,
I am wondering about the X11() graphic device on Windows.
I try to plot a raster image but nothing gets displayed. I
found some pages where it is mentioned that x11() not
always supports raster rendering.
Is there any add on for x11, any update or any R-package
which solves that displaying problem in Windows?
What I try to test it is an example from the
package {raster}:
library(raster)
2009 Oct 27
1
Exclude rows in xyplot
Hi all,
I'm searching for a way to exclude outliers from my dataset while making xyplots. While plotting using pairs(), I exclude specific row in my data frame and save the settings as a variable which I later include as an argument:
# Discard outliers and save settings as idx
idx=with(fieldTrial0809, which(Pro>0 & Pro<0.95 & Fum>0 & Fum<0.4 & Mal>0.1 &
2011 Sep 21
1
raster plot is empty
Dear R-help,
I have a problem plotting maps using the raster package when I use R
on my workplace server, but not when I use my own desktop. I suspect
the server version must be missing something and was wondering if
anyone would have any ideas.
The problem occurs after
library(raster)
f <- system.file("external/test.grd", package="raster")
r <- raster(f)
plot(f)
On