Displaying 20 results from an estimated 4000 matches similar to: "loess.smooth dumps core"
2005 Jul 12
1
getting panel.loess to use updated version of loess.smooth
I'm updating the loess routines to allow for, among other things,
arbitrary local polynomial degree and number of predictors. For now,
I've given the updated package its own namespace. The trouble is,
panel.loess still calls the original code in package:stats instead of
the new loess package, regardless of whether package:loess or
package:lattice comes first in the search list. If I
2018 May 09
0
unlist errors on a nested list of empty lists
I do not have access to the bug reporting system. If somebody can get me
access, I can create a formal bug report.
The latter issues seem like duplicates of:
https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=12572 (with slightly
different output), but as that bug was reported nearly 10 years ago, it
might be worth creating an update under R version 3. I could not find the
first issue when
2010 Sep 29
1
Obtaining lattice equivalent smoothed (loess) plot in ggplot
Hello,
I have been struggling to do a plot in ggplot(2) that's of lattice equivalent. The following code shows the lattice plot.
2013 Jan 18
1
lattice: loess smooths based on y-axis values
Hi there,
I'm using the lattice package to create an xy plot of abundance vs. depth for 5 stages of barnacle larvae from 5 species. Each panel of the plot represents a different stage, while different loess smoothers within each panel should represent different species.
However, I would like depth to be on the y-axis and abundance to be on the x-axis, because this is more intuitive as an
2009 Nov 19
1
loess smoothing
Hello,
In reading the loess description I see:
span: the parameter alpha which controls the degree of smoothing.
The default seems to be 0.75. Would it be possible to expand on this decription so I can avoid trail and error? Can I increase this pass 'span' > 1? Qualitatively to what degree changing this value affects the smoothing of the data?
Thank you.
Kevin
2023 Mar 23
1
loess plotting problem
Thanks, John.
However, loess.smooth() is producing a very different curve compared to the
one that results from applying predict() on a loess(). I am guessing they
are using different defaults. Correct?
On Thu, 23 Mar 2023 at 20:20, John Fox <jfox at mcmaster.ca> wrote:
> Dear Anupam Tyagi,
>
> You didn't include your data, so it's not possible to see exactly what
>
2011 Jul 12
1
LOESS function Newton optimization
I have a question about running an optimization function on an existing LOESS
function defined in R. I have a very large dataset (1 million observations)
and have run a LOESS regression. Now, I want to run a Newton-Raphson
optimization to determine the point at which the slope change is the
greatest.
I am relatively new to R and have tried several permutations of the maxNR
and nlm functions with
2023 Mar 23
1
loess plotting problem
Dear Anupam Tyagi,
You didn't include your data, so it's not possible to see exactly what
happened, but I think that you misunderstand the object that loess()
returns. It returns a "loess" object with several components, including
the original data in x and y. So if pass the object to lines(), you'll
simply connect the points, and if x isn't sorted, the points
2012 Apr 03
2
How does predict.loess work?
Dear R community,
I am trying to understand how the predict function, specifically, the
predict.loess function works.
I understand that the loess function calculates regression parameters at
each data point in 'data'.
lo <- loess ( y~x, data)
p <- predict (lo, newdata)
I understand that the predict function predicts values for 'newdata'
according to the loess regression
2010 Oct 26
2
anomalies with the loess() function
Hello Masters,
I run the loess() function to obtain local weighted regressions, given
lowess() can't handle NAs, but I don't
improve significantly my situation......, actually loess() performance leave
me much puzzled....
I attach my easy experiment below
#------SCRIPT----------------------------------------------
#I explore the functionalities of lowess() & loess()
#because I have
2012 Nov 20
2
Help with loess
Not sure what I'm doing wrong. Can't seem to get loess values. It looks like
loess is returning the same values as the input.
j <-loess(x1$total~as.numeric(index(x1)
plot(x1$total,type='l', ylab='M coms/y global',xlab='')
lines(loess(total~as.numeric(index(x1)),x1))
The plot statement works fine
No errors with the "lines" statement
But I don't
2005 Nov 17
3
loess: choose span to minimize AIC?
Is there an R implementation of a scheme for automatic smoothing
parameter selection with loess, e.g., by minimizing one of the AIC/GCV
statistics discussed by Hurvich, Simonoff & Tsai (1998)?
Below is a function that calculates the relevant values of AICC,
AICC1 and GCV--- I think, because I to guess from the names of the
components returned in a loess object.
I guess I could use
2012 Aug 08
1
Confidence bands around LOESS
Hi Folks,
I'm looking to do Confidence bands around LOESS smoothing curve.
If found the older post about using the Standard error to approximate it
https://stat.ethz.ch/pipermail/r-help/2008-August/170011.html
Also found this one
http://www.r-bloggers.com/sab-r-metrics-basics-of-loess-regression/
But they both seem to be approximations of confidence intervals and I was
wonder if there was
2010 Aug 27
3
predict.loess and NA/NaN values
Hi!
In a current project, I am fitting loess models to subsets of data in
order to use the loess predicitons for normalization (similar to what
is done in many microarray analyses). While working on this I ran into
a problem when I tried to predict from the loess models and the data
contained NAs or NaNs. I tracked down the problem to the fact that
predict.loess will not return a value at all
2011 Mar 18
1
Difficulty with 'loess' function
Hi,
I am trying to create a loess smooth from hydrologic data. My goal is to
create a smooth line that describes discharge at a certain point in time. I
have done this using the 'lowess' function and had no problem, but I'm
having some difficulty with loess. I am inputting the date ('date') and
discharge ('q') values using the 'scan' function, then inputting
2010 May 31
3
What does LOESS stand for?
Dear R-community,
maybe someone can help me with this:
I've been using the loess() smoother for quite a while now, and for
the matter of documentation I'd like to resolve the acronym LOESS.
Unfortunately there's no explanation in the help file, and I didn't
get anything convincing from google either.
I know that the predecessor LOWESS stands for "Locally Weighted
2012 Mar 10
1
How to improve the robustness of "loess"? - example included.
Hi,
I posted a message earlier entitled "How to fit a line through the
"Mountain crest" ..."
I figured loess is probably the best way, but it seems that the
problem is the robustness of the fit. Below I paste an example to
illustrate the problem:
tmp=rnorm(2000)
X.background = 5+tmp; Y.background = 5+ (10*tmp+rnorm(2000))
X.specific = 3.5+3*runif(1000);
2010 May 17
1
Loess fit
Hi,
I wonder why my attempt to extend an existing loess fit to a new data set is
producing error. I was trying the following:
dat = read.csv(choose.files())
x = dat[,2]; y = dat[,1]
x.sort = sort(x)
y.loess = loess(y~x, span=0.75)
# For testing the above fit with a new dataset:
test = read.csv(choose.files()) # test data
new_x = test [,1]; new_y = test[,2]
new_x.sort = sort(new_x)
predicted
2001 Feb 01
3
Rotated mtext
I seem to remember this coming up before, but I can't find it any messages I've
saved or in the archives (searching by subject). I want to rotate mtext so that
it's perpendicular to the right side. I tried srt=90 and lots of other values,
but it seems to be ignored. Is there a way to do this?
______________________________________________________________________
Stuart Luppescu
2011 Feb 07
1
tri-cube and gaussian weights in loess
>From what I understand, loess in R uses the standard tri-cube function.
SAS/INSIGHT offers loess with Gaussian weights. Is there a function in R
that does the same?
Also, can anyone offer any references comparing properties between tri-cube
and Gaussian weights in LOESS?
Thanks. - Andr?
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