search for: piecewise

Displaying 20 results from an estimated 181 matches for "piecewise".

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 @inproceedings{popov2016piecewise, title={Piecewise Holistic...
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 [[alternative HTML version deleted]]
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...
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...
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 and weights for a piecewise function as described, compar...
2018 Jan 30
0
Publication LLVM Related Publications Submission
...hose 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 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 > > > @inproceeding...
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 tw...
2004 Jan 21
2
Better way to find function
To whom it may concern, 1. I would like to know if there is a command in R to choose a function for a given dataset. I am facing a difficult question about how to fit the data [ please attachment ] 2. Are there any function that will allow users to do the piecewise regression? If not, is it going to be provide in the new updated version? What I am using is the piecewise logistic regression, but it doesn't have a continuous function though. I hope that R would have a specific command to do the piecewise (non)linear regression. I would apprecaite your...
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 impleme...
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& -- View this message in context: http://w...
2010 Jul 21
0
Piecewise regression using lme()
Hi everyone, I'm trying to fit a of piecewise regression model on a time series. The idea is to divide the series into segments and then to apply linear regression models on each segment but in a "global way" and considering heteroskedasticity between the segments. For example, I build a time series y with 3 segments: segment1=1:20...
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
2008 Jan 01
3
Specify a correct formula in R for Piecewise Linear Functions?
Dear all, I have two variables, y and x. It seems that the relationship between them is Piecewise Linear Functions. The cutpoint is 20. That is, when x<20, there is a linear relationship between y and x; while x>=20, there is another different linear relationship between them. How can i specify their relationships in R correctly? # glm(y~I(x<20)+I(x>=20),family = binomial, data = po...
2010 May 19
0
Piecewise nls w/ boundary as a fitting parameter
Hello, Fitting a piecewise smooth curve to a set of points (and a piecewise linear function in particular) seems to be a recurring question on this list. Nevertheless, I was not able to find an answer to a question that bothers me. Suppose I have the following data set, and would want to fit it with a piecewise smooth curve...
2012 Apr 05
1
how to do piecewise linear regression in R?
Dear all, I want to do piecewise CAPM linear regression in R: RRiskArb−Rf = (1−δ)[αMktLow+βMktLow(RMkt−Rf)] + δ[αMkt High +βMkt High(RMkt −Rf )] where δ is a dummy variable if the excess return on the value-weighted CRSP index is above a threshold level and zero otherwise. and at the same time add the restriction: αMkt Low +...
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...
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 degr...
2002 Dec 18
6
Can I build an array of regrssion model?
Hi, I am trying to use piecewise linear regression to approximate a nonlinear function. Actually, I don't know how many linear functions I need, therefore, I want build an array of regression models to automate the approximation job. Could you please give me any clue? Attached is ongoing code: rawData = scan("c:/zyang/m...
2008 Mar 24
1
Great difference for piecewise linear function between R and SAS
Dear Rusers, I am now using R and SAS to fit the piecewise linear functions, and what surprised me is that they have a great differrent result. See below. #R code--Knots for distance are 16.13 and 24, respectively, and Knots for y are -0.4357 and -0.3202 m.glm<-glm(mark~x+poly(elevation,2)+bs(distance,degree=1,knots=c(16.13,24)) +bs(y,de...
2005 Mar 05
1
S-code for piecewise regression
Dear R-helpers, a S-code for piecewise regressions was provided by Toms & Lesperance (2003) Ecology, 84, 2034-2041 (paper can be found on the web).The code is quite complete with different types of transitions around breakpoints and model selection fonctions. It doesn't work directly under R due to some "translation&quot...