Displaying 20 results from an estimated 2000 matches similar to: "Kriging with precalculated point-to-point distances?"
2007 Jul 05
1
(no subject)
I'm trying to hunt down an appropriate kriging package for my specific
application, and I was hoping someone on the R list might have some pointers
-- I'm interested in performing kriging and related spatial interpolations
with one of the R packages, but I need to be able to provide my own
point-to-point distances (e.g. I do not want to use standard between point
distances, as calculated
2009 Mar 18
2
How do I set the Windows temporary directory in R?
I'm trying to redirect where temporary files go under R to
D:\temp\somerandomname from its default (C:\Documents and
Settings\username\Temp\somerandomname) -- how do I go about doing this?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N
Davis, CA 95616
2009 Apr 07
1
Constrained, multiple response statistics
R'ers:
I was hoping I could get some direction on this. I have a dataset
of the form:
Y1,Y2,...,YM = f(X1,X2,...,XN), where N is >>> M
The response data (Y1,Y2,...,YM) is frequency data, such that the sum of
all Yi = 1.0. Both Xj and Yi are continuous variables.
I'm trying to figure out the best approach(es) to solving for the model
f() -- any ideas? I could solve
2009 Mar 13
2
Using format to add leading zeroes
I have a numerical vector which contains a (poorly) formatted time
column, which, in theory, should be HHMM, but was distributed as an
integer, so, for 12:15 am, it is saved as "15" (e.g. HHMM = 0015 with
the zeroes stripped). I'm trying to use this in conjunction with
strptime, but I'm thinking because each time is an integer ranging from
1 to 4 digits, I probably need to
2009 Jan 25
2
.Renviron for multiple hardwares...
Our lab has a lot of different unix boxes, with different hardware, and
I'm assuming (perhaps wrongly) that by setting a per-user package
installation directory, the packages will only work on one type of
hardware. Our systems are all set up to share the same home directory
(and, thus, the same .Renviron file) -- so, is there a way to set, in
the .Renviron file, per-computer or
2008 Oct 29
1
Suppressing internal grid in filled.contour
Rers:
I can't seem to locate the command to suppress what appears to be a
faint internal grid when running the following command to make a filled
contour plot of some data I have (x,y,z being the inputs):
2009 Jun 16
2
Statistically detecting thresholds...
Rers:
I have some ecological data (stream velocity vs. % cover of submerged
weeds) that shows strong evidence of a thresholding step-function, e.g.
below some velocity, % cover ranges from 0% to 100% (with no apparent
relationship to velocity within this range of velocities), but above a
certain "threshold" velocity, the % cover does not appear to exceed,
say, 10%. There are good
2009 Jun 18
1
Stratified random sampling?
Rers:
What is the preferred library/function for doing stratified random
sampling from a dataset, given I want to control the number of samples
(rather than the proportion of samples) per strata? Thanks!
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room
2009 Jul 10
1
file.copy returning "FALSE"?
I'm running the command:
file.copy(fnhdr,outdir,overwrite=TRUE)
Which successfully copies the file I want to the directory I want, but
each time it prints "FALSE" -- what does this mean, and how do I
suppress this output?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One
2009 Mar 16
1
Best way to do temporal joins in R?
I've been playing with zoo a bit, and it seems ok except it doesn't
support non-unique time stamps when performing joins. I have two
databases which contain a dataframe of a Date object (with the time, not
just MM/DD/YY), e.g.:
DB 1:
UniqueID,Date1,Data 1,Data 2
DB 2:
Date2, Station, Data 3
We'll say Station can contain three values: A,B and C
DB 1 may have some repeat times,
2009 Oct 23
2
splitting a vector of strings...
Quick question -- if I have a vector of strings that I'd like to split
into two new vectors based on a substring that is inside of each string,
what is the most efficient way to do this? The substring that I want to
split on is multiple characters, if that matters, and it is contained in
every element of the character vector.
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
2009 Nov 02
2
"Safe" way to automatically install required packages...
R-helpers:
I'm working on an r-package that I want to make as easy-to-use as
possible for a novice R-user, which includes automatically installing
required packages. I, myself, am a novice R-packager, so the solution
I came up with was to embed:
print("Loading required packages...")
if (!require("reshape")) { install.packages("reshape") }
if
2010 Jan 28
2
Data frame of different sized lists in a function call
I'm hoping to get some "best practice" feedback for constructing a
function call which takes an undefined set of DIFFERENT length vectors
-- e.g. say we have two lists:
list1=c(1:10)
list2=c(2:4)
lists = data.frame(list1,list2) coerces those two to be the same length
(recycling list2 to fill in the missing rows) -- what is a quick way of
having each of those lists retain their
2009 Aug 30
1
Stochastic (transition) matrices: how to determine distributions and variance?
(apologies for the cross-posting, and for this being a more general
stats question rather than a specific-to-R one. I assure you I will be
doing the actual analysis in R :)
I am trying to determine the distribution and variance for a classic
stochastic (transition) matrix problem such that:
let x(t) be an initial state vector consisting of counts of classes A, B
and C:
x(t) =
2009 Aug 27
19
Best R text editors?
Quick informal poll: what is everyone's favorite text editor for working
with R? I'd like to hear from people who are using editors that have
some level of direct R interface (e.g. Tinn-R, Komodo+SciViews). Thanks!
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The
2010 Jan 20
1
x,y plot question (two sets of labels)
I'm trying to figure out the best way to do a scatterplot using the
following data as an example:
plothelp_x=1:10
plothelp_A1=sin(plothelp_x)
plothelp_A2=tan(plothelp_x)
plothelp_B=c("A","B","C","A","B","C","A","B","C","A")
(note that all 4 of these vectors have 10 entries each)
What I would
2009 Oct 28
1
Aggregate and cross tabulation
R-helpers:
I have a data frame containing 4 factor variables (let's say A,B,C,
and D) and 1 numerical variable (N). I would like to produce a
cross-tabulated data frame in which A,B,C are individual columns, each
factor of D is its own column, and the field is calculated as a given
function of N (I would like to have two output data frames, one with the
mean(N) and one with the
2008 Nov 05
1
Using RGDAL to "copy" header information...
R-geographers...
I'm trying to solve a problem to implement a line-by-line tiled
processing using RGDAL (read 1 line of an image, process the one line,
write one line of the image to a binary file). Everything except for
the final step I'm able to do using a combination of RGDAL and r-base
commands. Below is the basic structure, the input file "elev" can be
any image file
2010 Jan 30
2
Using auto.key with two variable plots
Rhelpers:
Having a problem solving this. I have an xyplot call that looks
like this:
print(xyplot(temp_species_EAM_Pred_Pop$x+temp_species_NULL_Pred_Pop$x~temp_species_EAM_Pred_Pop$Action,main=current_species,
xlab="Action",ylab="Predicted Pop",
xlim=c(xmin,xmax),ylim=c(ymin,ymax),
2009 Jul 12
2
strata -- really slow performance
I'm a bit confused why the following command is taking an extrodinarily
long time (> 2-3 hours) to run on an 3.06ghz iMac (brand new). I'm
trying to do a stratified random sample, drawing only a single value per
UniqueID from the patch_summary data frame:
uniqueids <- unique(patch_summary$UniqueID)
uniqueids_stratasize <- c(1:length(uniqueids))*0+1