similar to: Bayesian constrained regression method?

Displaying 20 results from an estimated 10000 matches similar to: "Bayesian constrained regression method?"

2010 Nov 30
2
Adding noise
Hello, I have some discrete pvalues and I would like to sort them. Then add random noise so that they are ordered the same way as the original pvalues. Off course I don't want any pvalues less than 0 or greater than 1. Any ideas on how to do this in R? -- Thanks, Jim. [[alternative HTML version deleted]]
2010 Oct 31
2
Constrained Regression
Hello everyone, I have 3 variables Y, X1 and X2. Each variables lies between 0 and 1. I want to do a constrained regression such that a>0 and (1-a) >0 for the model: Y = a*X1 + (1-a)*X2 I tried the help on the constrained regression in R but I concede that it was not helpful. Any help is greatly appreciated -- Thanks, Jim. [[alternative HTML version deleted]]
2007 Jul 12
1
how to estimate treatment-interaction contrasts
Hello, R experts, Sorry for asking this question again again since I really want a help! I have a two-factor experiment data and like to calculate estimates of interation contrasts say factor A has levels of a1, a2, and B has levels of b1, b2, b3, b4, and b5 with 3 replicates. I am not sure the constrast estimate I got is right using the script below:
2010 Jun 22
1
Bayesian Code for contingency tables
Hello, Is there anywhere I can find some Bayesian Code for 2 by 2 tables or even the non-central hypergeometric distribution in R? Packages would be helpful but the actual coding in R is much better. Thanks, Thanks Jim [[alternative HTML version deleted]]
2011 Apr 24
1
EM vs Bayesian
Hello, Is there any literature there that says that the EM is better/worse than a Baysian model when it comes to differentiating univariate mixture of normal distributions? -- Thanks, Jim. [[alternative HTML version deleted]]
2011 Mar 16
2
Re; Fitting a Beta distribution
I want to fit some p-values to a beta distribution. But the problem is some of the values have 0s and 1's. I am getting an error if I use the MASS function to do this. Is there anyway to get around this? -- Thanks, Jim. [[alternative HTML version deleted]]
2012 Oct 21
1
Linear discriminant function analysis based median as group centroid and nonparametric scale estimators???
Dear All, I am using a specific approach for my master thesis. In essence, a supervised reclassification is used as an intermediate step to find chemical parameters which are able to reclassify defined groups. These variables will be used in a next step where location and scale estimators of the groups are important. Traditionally linear discriminant analysis is used for reclassification which
2008 Mar 05
6
box-constrained
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?... Nom : non disponible Url : https://stat.ethz.ch/pipermail/r-help/attachments/20080305/80536e8c/attachment.pl
2005 Mar 17
1
Optimization of constrained linear least-squares problem
Dear R-ians, I want to perform an linear unmixing of image pixels in fractions of pure endmembers. Therefore I need to perform a constrained linear least-squares problem that looks like : min || Cx - d || ? where sum(x) = 1. I have a 3x3 matrix C, containing the values for endmembers and I have a 3x1 column vector d (for every pixel in the image). In theory my x values should all be in the
2010 Nov 17
2
How to catch warnings
Hello when my code executes I receive the message that were some warnings. I want to catch warning messages at run time so to print some local variables and try to understand why this warning happens. I searched on internet and I tried withCallingHandlers( which seems to work but as I used Rkward the result is awful. I get a prompt to copy paste a value only while at the same time my background
2006 Sep 27
2
Constrained OLS regression
Hello R helpers, I am trying to do a linear OLS regression of y on two variables x1 and x2. I want to constrain the coefficients of x1 and x2 to sum up to 1. and therefore run a constrained OLS. Can anybody help with this? (I have seen some answers to similar questions but it was not clear to me what I need to do) - I have tried the lm function with offset but I must not have used it properly.
2011 Aug 22
3
Changing data scales
I have data that ranges from 0.3 to 2 and I want to change the scale to be from 0 to 1. Can this be done in R? -- Thanks, Jim. [[alternative HTML version deleted]]
2007 Nov 28
2
fit linear regression with multiple predictor and constrained intercept
Hi group, I have this type of data x(predictor), y(response), factor (grouping x into many groups, with 6-20 obs/group) I want to fit a linear regression with one common intercept. 'factor' should only modify the slopes, not the intercept. The intercept is expected to be >0. If I use y~ x + factor, I get a different intercept for each factor level, but one slope only if I use y~ x *
2010 Sep 23
3
accumulation curves
Hi, I am trying to fit a logarithmic trendline to a scatterplot of a species accumulation curve. I've tried abline, lines, curve and scatter.smooth but none of these work. Can anyone help please, Kyran
2009 Nov 04
3
Constrained Optimization
Hi All, I'm trying to do the following constrained optimization example. Maximize x1*(1-x1) + x2*(1-x2) + x3*(1-x3) s.t. x1 + x2 + x3 = 1 x1 >= 0 and x1 <= 1 x2 >= 0 and x2 <= 1 x3 >= 0 and x3 <= 1 which are the constraints. I'm expecting the answer x1=x2=x3 = 1/3. I tried the "constrOptim" function in R and I'm running into some issues. I first start off
2003 Oct 31
1
constrained nonlinear optimisation in R?
Hello. I have searched the archives but have not found anything. I need to solve a constrained optimisation problem for a nonlinear function (“maximum entropy formalism”). Specifically, Optimise: -1*SUM(p_ilog(p_i)) for a vector p_i of probabilities, conditional on a series of constraints of the form: SUM(T_i*p_i)=k_i for given values of T_i and k_i (these are constraints on
2012 Jan 13
0
New package ‘bcrm’ to implement Bayesian continuous reassessment method designs
Dear R users, I am pleased to announce the release of a new packaged called `bcrm? (version 0.1), now available on CRAN. The package implements a wide range of Bayesian continuous reassessment method (CRM) designs to be used in Phase I dose-escalation trials. The package is fully documented and highlights include ? A choice of 1-parameter working models or the 2-parameter logistic model.
2012 Jan 13
0
New package ‘bcrm’ to implement Bayesian continuous reassessment method designs
Dear R users, I am pleased to announce the release of a new packaged called `bcrm? (version 0.1), now available on CRAN. The package implements a wide range of Bayesian continuous reassessment method (CRM) designs to be used in Phase I dose-escalation trials. The package is fully documented and highlights include ? A choice of 1-parameter working models or the 2-parameter logistic model.
2010 Aug 24
1
Constrained non-linear optimisation
I'm relatively new to R, but I'm attempting to do a non-linear maximum likelihood estimation (mle) in R, with the added problem that I have a non-linear constraint. The basic problem is linear in the parameters (a_i) and has only one non-linear component, b, with the problem being linear when b = 0 and non-linear otherwise. Furthermore, f(a_i) <= b <= g(a_i) for some (simple) f
2011 Jan 11
3
Generation of Normal Random Numbers
Dear R helpers I have a data frame as given below df = data.frame(A = c(776,827,836,995,855,1026,1203,1363,965,1195),                        B = c(806,953,1049,1056,1243,764,1148,1162,948,1154),                        C = c(959,1155,1193,1163,863,1070,1087,877,1132,944),                        D = c(906,760,978,1170,1009,883,1007,960,828,113)) # Actually the real data has number of vectors and