Displaying 20 results from an estimated 5000 matches similar to: "Better way to find function"
2017 Jun 23
1
Piecewise continuous logistic regression with one knot
How can I fit a piecewise continuous logistic regression with a single free knot (i.e. the knot is not specified; the model produce an estimate of the value of the knot).
Thank you,
John
John David Sorkin M.D., Ph.D.
Professor of Medicine
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine
Baltimore VA Medical Center
2024 Jul 26
1
Automatic Knot selection in Piecewise linear splines
dear all,
I apologize for my delay in replying you. Here my contribution, maybe
just for completeness:
Similar to "earth", "segmented" also fits piecewise linear relationships
with the number of breakpoints being selected by the AIC or BIC
(recommended).
#code (example and code from Martin Maechler previous email)
library(segmented)
o<-selgmented(y, ~x, Kmax=20,
2024 Jul 16
2
Automatic Knot selection in Piecewise linear splines
>>>>> Anupam Tyagi
>>>>> on Tue, 9 Jul 2024 16:16:43 +0530 writes:
> How can I do automatic knot selection while fitting piecewise linear
> splines to two variables x and y? Which package to use to do it simply? I
> also want to visualize the splines (and the scatter plot) with a graph.
> Anupam
NB: linear splines, i.e. piecewise
2024 Jul 09
1
Automatic Knot selection in Piecewise linear splines
How can I do automatic knot selection while fitting piecewise linear
splines to two variables x and y? Which package to use to do it simply? I
also want to visualize the splines (and the scatter plot) with a graph.
Anupam
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2009 Nov 05
1
Simulate data for spline/piecewise regression model
Dear All,
I am trying to simulate data for a spline/piecewise regression model. I am missing something fundamental in my simulation procedure because when I try to fit my simulated data using the Gauss-Newton method in SAS, I am getting some wacky parameter estimates. Can anyone please check my simulation code and tell me what mistake I am making in generating data for spline model?
Thank you
2013 Jan 10
2
piece-wise linear regression nls function
windows 7, R 2.12
I am trying to run a piecewise linear regression with a single knot, i.e. a regression composed of two straight lines where the two lines intersect at an x value given by the variable knot. I wish to estimate the slope of both lines, the value of knot, the x value where the two lines intersect, and an intercept. I am using the nls code below, and get the following error
2017 Nov 28
2
Publication LLVM Related Publications Submission
Hello,
I would like to submit two papers that use LLVM to the
Related Publications section.
Both papers focus on code isolation
applied to perform piecewise compiler optimizations.
The code isolation
process is performed by CERE, an open source tool based on LLVM.
The
second paper is an extended version of the first one.
1) Piecewise
Holistic Autotuning of Compiler and Runtime Parameters
2018 Jan 30
0
Publication LLVM Related Publications Submission
Dear Mihail,
I've added these two publications to the publications page. Please
review it and let me know if I need to make any changes. In particular,
if you have URLs to use for the papers, having those would be greatly
appreciated.
Regards,
John Criswell
On 11/28/17 12:05 PM, Mihail Popov via llvm-dev wrote:
>
> Hello,
>
> I would like to submit two papers that use LLVM
2001 Dec 05
4
Questions about piecewise spline fitting
Hi All,
I want to fit a piecewise spline of degree 1, i.e. a spline consisting of a
straight line over each piece. I downloaded the R package pspline, then I
have following questions:
1. in the program, the degree of the spline is specified by 2*norder-1. Why
do they adopt such scheme that we can only fit a spline with odd degree?
2. norder cannot be set to 1. Is there any specific reason
2007 Jun 25
1
gam function in the mgcv library
I would like to fit a logistic regression using a smothing spline, where the spline is a piecewise cubic polynomial. Is the knots option used to define the subintervals for each piece of the cubic spline? If yes and there are k knots, then why does the coefficients field in the returned object from gam only list k coefficients? Shouldn't there be 4k -4 coefficients?
Sincerely,
Bill
2010 Jan 04
2
Piecewise regression in lmer
Dear all,
I'm attempting to use a piecewise regression to model the trajectory
of reproductive traits with age in a longitudinal data set using a
mixed model framework. The aim is to find three slopes and two points-
the slope from low performance in early age to a point of high
performance in middle age, the slope (may be 0) of the plateau from
the start of high performance to the
2012 Mar 25
2
Simple question regarding domain restrictions/piecewise functions in R
I am a novice R user.
I would like to be able to graph some simple piecewise functions/functions
with domain restrictions in R, but I'm having trouble defining such
functions. For example, I would like to define the following function:
f(x)={x^2 if -1<x<x; 1 if 2<x<3}
Notably, the function is undefined outside of domain (-1,1)U(2,3). My best
attempt in R is something like
2009 Mar 25
1
Piecewise
Hi,
I am a biologist (relatively new to R) analyzing data which we predict
to fit a power function. I was wondering if anyone knew a way to model
piecewise functions in R, where across a range of values (0-x) the data
is modeled as a power function, and across another range (x-inf) it is a
linear function. This would be predicted by one of our hypotheses, and
we would like to find the AICs
2000 Jul 27
1
Interpolation using a piecewise linear function in higher dimensions
Dear all,
I am just wondering if anybody has implemented a function that can give a
piecewise linear interpolation in more than 2 dimensions?
I have looked at the akima package, but I would rather like a piecewise
linear interpolation rather than a spline and while it did the job quite
satisfactory for 2 dimensions, I need to interpolate in at least three
dimensions. If anybody has implemented
2007 May 08
1
Piecewise cubic Hermite interpolation
Which function implements the piecewise cubic Hermite interpolation?
I am looking for equivalent of matlab's interp1 with the method = 'pchip'
Here is the reference
http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/interp1.html&
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2012 Jun 05
1
Piecewise Lasso Regression
Hi All,
I am trying to fit a piecewise lasso regression, but package Segmented does not work with Lars objects.
Does any know of any package or implementation of piecewise lasso regression?
Thanks,
Lucas
2012 Jan 17
4
breakpoints and nonlinear regression
Dear Forum,
I have been wracking my head over this problem for the past few days. I have
a dataset of (x,y). I have been able to obtain a nonlinear regression line
using nls. However, we would like to do some statistical analysis. I would
like to obtain a confidence interval for the curve. We thought we could
divide up the curve into piecewise linear regressions and compute CIs from
those
2011 Jan 14
4
piecewise regression
Hello everybody!!!!
Quick question, if you'd like to throw a little tip:
does anyone knows a function that runs piecewise regression models with
coefficients estimation and inferences ?
Thank you
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2005 May 30
3
Piecewise Linear Regression
Hi,
I need to fit a piecewise linear regression.
x = c(6.25,6.25,12.50,12.50,18.75,25.00,25.00,25.00,31.25,31.25,37.50,37.50,50.00,50.00,62.50,62.50,75.00,75.00,75.00,100.00,100.00)
y = c(0.328,0.395,0.321,0.239,0.282,0.230,0.273,0.347,0.211,0.210,0.259,0.186,0.301,0.270,0.252,0.247,0.277,0.229,0.225,0.168,0.202)
there are two change points. so the fitted curve should look like
\
\ /\
2003 May 02
1
stepfuns: R^2 -> R
Does anyone have any suggestions on perspective plotting of piecewise constant functions?
Ideally, I would like something like plot.stepfun for functions that are piecewise
constant on polygons. Even pointers to non-R strategies would be welcome at this stage.
url: www.econ.uiuc.edu Roger Koenker Dept. of Economics UCL,
email rkoenker at uiuc.edu Department of Economics Drayton House,
vox: