Displaying 20 results from an estimated 10000 matches similar to: "smoothing line and a pair of confidence intervals"
2010 Sep 03
2
density() with confidence intervals
Hello R users & R friends,
I just want to ask you if density() can produce a confidence interval, indicating how "certain" the density() line follows the true frequency distribution based on the sample you feed into density().
I've heard of loess.predict(loess(y ~ x), se=TRUE) which gives you a SE estimate of the smoothed scatterplot - but density() kernel smoothing is not the
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
2012 Mar 06
1
LOESS confidence interval
Dear all,
I'm trying to construct confidence intervals for a LOWESS estimation (by not using bootstrapping).
I have checked previous posts and other material online and I understand that the main procedure is:
my.count<- seq(...)
fit<- loess (y ~ x, data=z)
pred<- pred(fit, my.count, se=TRUE)
and then the plotting.
However, it's not working; as confidence
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
2011 Aug 08
2
confidence interval as shaded band (lme)
Hi all,
I?m trying to plot confidence intervals for the fitted values I get with my
lme model in R.
Is there any way I can plot this in the form of a shaded band, like the
output of geom_smooth() in ggplot2 package. ggplot2 seems to use only lm,
glm, gam, loess and rlm as smoothing methods.
Any advice on the functions I should use to accomplish this will be very
helpful.
Thank you very much.
2005 Nov 01
2
kernel smoothing
Dear all,
I want to use kernel estimator to smooth some step funtions such as the empirical distribution and hazard function in survival analysis. Is there a function or package to deal with it in R?
How do I use it?
Thanks for your help.
Jimmy
2000 Nov 15
2
loess documentation
Hi all,
I 've got a question about the usage of loess in the modreg package.
The documentation (loess.html) states that the smoothing window is
either set by span or enp.target. If span is used, the details section
of the docs state...
<SNIP>
DETAILS
Fitting is done locally. That is, for the fit at point x, the fit is
made using points in a neighbourhood of x, weighted by their
2000 Nov 15
2
loess documentation
Hi all,
I 've got a question about the usage of loess in the modreg package.
The documentation (loess.html) states that the smoothing window is
either set by span or enp.target. If span is used, the details section
of the docs state...
<SNIP>
DETAILS
Fitting is done locally. That is, for the fit at point x, the fit is
made using points in a neighbourhood of x, weighted by their
2009 Jul 26
1
How to add 95% confidence intervals in the calibration plot?
Dear experts:
I am a newbie to R. Recently, I try to make prediction models with R and the
Design library.
I have read Prof. Harrell's excellent book. But I did not quite understand.
I have two problems about the validation and calibration of prediction
models:
1. Can someone explain the results outputted by the validate() function? How
to get 95% of c-value of validate?
2. How to add 95% ci
2000 Apr 30
0
Help Need with aov()
Hi there,
I'm using R1.0.1 Windows 98.
This file contains some inputs and an aov function code. Can someone
check it for me? Somehow I got completely different answer when typing
them in R and in Splus.
Splus gives me this:
> summary( Turnip.aov )
Error: Blocks
Df Sum of Sq Mean Sq F Value Pr(F)
Residuals 3 163.7367 54.57891
Error: Plots %in% Blocks
2011 Jul 18
1
Extract confidence intervals from rma object (metafor package)
Dear R-experts!
I am working on some meta-analysis using the metafor package. I would like
to extract values of the confidence intervals of the effect sizes of the
single studies from an rma object. Those values are printed out when
plotting a forest plot using the forest function on the rma object, however
I was not able to locate them.
Many thanks for your help!
Jokel
[[alternative HTML
2010 May 11
3
Smoothing Techniques - short stepwise functions with spikes
R Friends,
I have data from which I would like to learn a more general
(smoothened) trend by applying data smoothing methods. Data points
follow a positive stepwise function.
| x
x
| xxxxxxxx xxxxxxxx
| x x
|xxxx xxx xxxx
| xxxxxxxxxxxxxxxxx
|
|
2002 Sep 15
7
loess crash
Hi,
I have a data frame with 6563 observations. I can run a regression with
loess using four explanatory variables. If I add a fifth, R crashes. There
are no missings in the data, and if I run a regression with any four of the
five explanatory variables, it works. Its only when I go from four to five
that it crashes.
This leads me to believe that it is not an obvious problem with the data,
2003 Mar 27
2
Na action with Lowess smoothing
Hi there,
I cant seem to find a way for the lowess smoothing function to handle "NA"
values.
Can anyone help??
Regards,
Wayne
Dr Wayne R. Jones
Statistician / Research Analyst
KSS Group plc
St James''s Buildings
79 Oxford Street
Manchester M1 6SS
Tel: +44(0)161 609 4084
Mob: +44(0)7810 523 713
KSS Ltd
A division of Knowledge Support Systems Group plc
Seventh Floor St
2001 Mar 12
2
residuals from lowess fit
Colleagues
----------------------------------
System info:
R version rw1022 on NT
ESS v. 5.1.18 using emacs ver. 20.4
----------------------------------
I would like to access the residuals from a lowess fit (function lowess() )
as an aid to assessing whether I am over-smoothing or under-smoothing
a dataset (as in Cleveland's book "Visualizing data", section 3.3)
Unless I
2013 Apr 20
0
Calculate confidence intervals in mgcv for unconditional on the, smoothing parameters
Dear R-Help members,
I am using Simon Wood`s mgcv package version1.7-22and R version 3.0.0
(2013-04-03) for fitting a GAM-Model to the LIDAR Data contained in the
"SemiPar" package. Here is the code for fitting the model and for
plotting the result:
data("lidar")
attach(lidar)
###
# mgcv fitting
###
gam_fit <- gam(logratio ~ s(range, k = 40, bs = "cr"), gamma
2011 Jun 04
1
nonparametric logistic regression based on locally weighted scatterplot smoothing (lowess)
Dear UseRs:
Recently, I have read an article regarding the association between age and
lymph node metastases.
http://jco.ascopubs.org/content/27/18/2931.long
In statistical analysis, the authors stated "Because a nonlinear
relationship between age and lymph node involvement was expected based on
existing literature, lymph node involvement was also regressed on age using
nonparametric
2012 Jun 19
2
Smoothing a persp graph
Hi,
I'm unable to find a way to smooth data for a persp() graph.
Example, suppose that I have data x,y,z like this:
x <- 1:10
y <- 1:10
k <- 20
z <- outer(x, y, "*") + matrix( k*runif(100, -1, 1), 10, 10)
persp(x, y, z, theta = 35, phi = 25)
The graph is not very nice. Is there a way to smooth the z data so that at the end the graph would look more like something
2006 Mar 16
1
running median and smoothing splines for robust surface f itting
loess() should be able to do robust 2D smoothing.
There's no natural ordering in 2D, so defining running medians can be
tricky. I seem to recall Prof. Koenker talked about some robust 2D
smoothing method at useR! 2004, but can't remember if it's available in some
packages.
Andy
From: Vladislav Petyuk
>
> Hi,
> Are there any multidimenstional versions of runmed() and
>
2000 Aug 09
2
pch and curve plotting
Hi all,
I'm having two small problems and was wondering if you could help me
out.
Problem 1:
When I use pch to place a symbol onto a plot it seems to place the point
a little off the exact location. I have read the help file for this
which says to use "." as the plotting character, which will then produce
centered points but I am unclear as to how to do this.
Problem 2: How do I