Displaying 20 results from an estimated 1000 matches similar to: "lasso for variable selection"
2006 Jul 19
2
voronoi tessellations
Okay, been working with tripack, seems the most mature package for this. Got it to work well with their test data set - data(tritest). When i tried random numbers to explore further, i am getting some results that don't reconcile.
example run this:
library(tripack)
y <- runif(100)
x <- runif(100)
vm <- voronoi.mosaic(x,y)
plot(vm)
par(new=T)
plot(x,y,col='blue')
when
2011 Feb 24
1
weighted Voronoi diagrams
Dear R-users,
Does anyone know how to do weighted Voronoi diagrams (Dirichlet
tesselation) in R? To be more specific, I have a set of coordinates for
tree locations on a plot, and I'm looking for a way to do the
tesselation so that the polygon size for each tree depends on the size
of the subject tree, and the size of its neighbors. So, the location of
the bisection between two trees
2003 Nov 21
3
plot map of areas
Hi all,
Given a number of points (x,y) in a plane, I'd like to plot a map of
polygons, so that
1) each polygon contains exactly one point
2) the polygon defines the area for which this specific point is
closer than any other point.
It's a bit like a map of areas "influenced" by that point, and it's
obviously a matter of intersecting the perpendicular bisectors
2005 May 31
3
lars / lasso with glm
We have been using Least Angle Regression (lars) to help identify
predictors in models where the outcome is continuous. To do so we have
been relying on the lars package. Theoretically, it should be possible
to use the lars procedure within a general linear model (glm) framework
- we are particular interested in a logistic regression model. Does
anyone have examples of using lars with logistic
2018 Jan 24
4
Geometry delaunayn and deldir results, differing results from Octave due to decimal precision?
The problem:
I would like to translate the Octave algorithm in griddata.m to R.
Within the griddata algorithm calls are made to the Delaunay function. For the R translation I have found delaunayn within the "geometry" package and also the deldir package.
Both do similar things but give slightly different results depending on the input.
The question is, what is making the results for the
2015 May 18
2
[PATCH] nvc0: fix context destruction for partly implemented tesselation
Backtrace:
...
0x00007ffff57fc392 in __assert_fail () from /lib64/libc.so.6
0x00007ffff0cf5bec in nvc0_shader_stage (pipe=<optimized out>) at ./nvc0/nvc0_context.h:204
nvc0_set_constant_buffer (pipe=0x631080, shader=<optimized out>, index=<optimized out>, cb=0x0)
at nvc0/nvc0_state.c:771
0x00007ffff0a2cf63 in st_destroy_context (st=0x68a9f0) at state_tracker/st_context.c:382
2018 Jan 24
0
Geometry delaunayn and deldir results, differing results from Octave due to decimal precision?
"The question is, what is making the results for the R packages different
from each other?"
There are literally thousands of R packages, contributed independently by
thousands of people. There should be no expectation of consistency or for
that matter, "correctness", among them. Caveat emptor.
Only within the base R distribution, maintained and mostly written by the R
Core
2017 Nov 30
1
How to count instructions in a function?
Thanks so much John! That works :)
Previously I wrote a pass that inherited from CallGraphWrapperPass and used
its getCallGraph() function within runOnModule() which resulted in
segmentation faults for me. Not sure why that happened, perhaps callgraph
wasn't setup by the time runOnModule() was called internally. If you know
why, kindly enlighten me and perhaps document the behavior for the
2006 Apr 06
1
rounding of voronoi vertices using deldir()
Hello list,
I'm just getting started with using R - I have been trying over the past
day or so to work out a method for generating voronoi polygons for
PostGIS using SQL. I was able to put together a procedure which works
relatively well, but is somewhat inefficient. Someone on the PostGIS
list pointed me to the deldir() function in R, for which I can export a
text file with x/y coordinates
2009 May 10
1
Spatstat
Hi all,
I am trying to install Spatstat on OpenSUSE 11.1.
install.packages("spatstat", dependencies = TRUE)
fails on the basis of various compiler packages (full message below).
I have gcc version 4.3.2, which should include gfortran and g++ - so I'm not
sure what to do!
Richard
* Installing *source* package ?deldir? ...
** libs
gfortran
2007 Nov 27
1
voronoi/Delaunay/Dirichlet tessellation on sphere in R or S?
There's Renka's STRIPACK, and TRIPACK, respectively, ACM TOMS Algorithms
772 and 751, and there's the R package "deldir" which does the Delaunay
for a plane, but does anyone have or know of the tessellation in R for a
sphere?
Also, is there a standard indexing scheme for Delaunay facets, and
perhaps of edges in such facets? I'd expect that to be a publication
reference,
2016 Apr 17
6
how do I use only black ink?
I have an HP Photosmart C3180 All-in-one.
As I haven't had any need for color lately,
when I last replaced ink, I only replaced the black cartridge.
It didn't work, even when printing grayscale-only images,
even when telling print-set-up grayscale-only.
Is there a way to tell my printer to use only the black ink cartridge.
My test image is a handmade postscript file
that only use setgray
2010 May 12
2
Finding different hues for a mosaic plot compatible with grayscale printing
I'm working with the following code below to generate a
how do I set the h,c, and l values such that the significant, positive
residuals appear different on a grayscale printer from significant
grayscale residuals. The challenge as I see it is that one can only
distinguish the positive and negative residuals with the hue/. Varying
the chroma and the luminance only affect the
2012 Jul 18
1
convert deldir$delsgs to a X3D IndexedTriangleSet
Anyone knows how to convert a deldir$delsgs to a X3D IndexedTriangleSet?
Are there already any functions/packages?
[[alternative HTML version deleted]]
2016 Apr 18
2
how do I use only black ink? success
On Sun, 17 Apr 2016, Michael Hennebry wrote:
> On Sun, 17 Apr 2016, Michael Hennebry wrote:
>
>> I have an HP Photosmart C3180 All-in-one.
>> As I haven't had any need for color lately,
>> when I last replaced ink, I only replaced the black cartridge.
>> It didn't work, even when printing grayscale-only images,
>> even when telling print-set-up
2007 Jul 28
2
lattice grayscale "theme"
Hi,
is there a grayscale setting for lattice plots?
I like the default color settings. I also like the settings that are
available for setting black and white with something like this:
--8<---------------cut here---------------start------------->8---
ltheme <- canonical.theme(color = FALSE) ## in-built B&W theme
ltheme$strip.background$col <- "transparent" ##
2009 Nov 26
13
How to display an image on RGL plot?
Hi all.
It's been a long time since I wrote to this list. Glad to see the R project
well and working.
I am working with a 3D plot similar to this:
http://old.nabble.com/file/p26525177/rgl-device.png rgl-device.png
The underlying picture is a JPEG image, loaded with the rimage package and
coerced to the matrix.
Spheres denote control points, collected from this picture and must be
2011 Jun 06
1
Lasso for k-subset regression
Dear R-users
I'm trying to use lasso in lars package for subset regression, I have a
large matrix of size 1000x100 and my aim is to select a subset k of the 100
variables.
Is there any way in lars to fix the number k (i.e. to select the best 10
variables)
library(lars)
aa=lars(X,Y,type="lasso",max.steps=200)
plot(aa,plottype="Cp")
aa$RSS
which.min(aa$RSS)
2010 Dec 06
2
How to get lasso fit coefficient(given penalty tuning parameter \lambda) using lars package
Hi, all,
I am using the lars package for lasso estimate. So I get a lasso
fit first:
lassofit = lars(x,y,type ="lasso",normalize=T, intercept=T)
Then I want to get coefficient with respect to a certain value of \lambda
(the tuning parameter), I know lars has three mode options c("step",
"fraction", "norm"), but can I use the \lambda value instead
2007 Jun 12
1
LASSO coefficients for a specific s
Hello,
I have a question about the lars package. I am using this package to get the coefficients at a specific LASSO parameter s.
data(diabetes)
attach(diabetes)
object <- lars(x,y,type="lasso")
cvres<-cv.lars(x,y,K=10,fraction = seq(from = 0, to = 1, length = 100))
fits <- predict.lars(object, type="coefficients", s=0.1, mode="fraction")
Can I assign