Displaying 20 results from an estimated 10000 matches similar to: "logistic regression with constrained coefficients?"
2020 Oct 30
1
[External] Re: Change to I() in R 4.1
On Fri, 30 Oct 2020, Pages, Herve wrote:
>
> On 10/29/20 23:08, Pages, Herve wrote:
> ...
>>
>> I can think of 2 ways to move forward:
>>
>> 1. Keep I()'s current implementation but suppress the warning. We'll
>> make the necessary adjustments to DataFrame() to repair columns supplied
>> as I(<S4>) objects. Note that we would still be in
2008 Sep 28
0
constrained logistic regression: Error in optim() with method = "L-BFGS-B"
Dear R Users/Experts,
I am using a function called logitreg() originally described in MASS (the
book 4th Ed.) by Venebles & Ripley, p445. I used the code as provided but
made couple of changes to run a 'constrained' logistic regression, I set the
method = "L-BFGS-B", set lower/upper values for the variables.
Here is the function,
logitregVR <- function(x, y, wt =
2005 Aug 28
1
Logistic regression with constrained parameter ??
I want to fit a logistic regression model under a specified
null hypothesis, say Ho:Beta_k=1
Is there a way to constrain a parameter in glm.fit ??
Thanks in advance!
---------------------------------
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2008 Oct 06
3
[LLVMdev] sext..to instruction
Hi,
I have a question about the "sext..to" instruction. In the document, I found
two examples:
%x = sext i8 -1 to i16
It means:
i8 -1 = 1111 1111 --> 1111 1111 1111 1111 = i16
how can it determinate, that the i16 value %x positive is (65535)?
And the second example:
%y = sext i1 true to i32
1 --> 1111 1111 1111 1111 1111 1111 1111 1111
In this example, %y is -1
I'm not sure
2010 Dec 29
1
logistic regression with response 0,1
Dear Masters,
first I'd like to wish u all a great 2011 and happy holydays by now,
second (here it come the boring stuff) I have a question to which I hope u
would answer:
I run a logistic regression by glm(), on the following data type
(y1=1,x1=x1); (y2=0,x2=x2);......(yn=0,xn=xn), where the response (y) is
abinary outcome on 0,1 amd x is any explanatory variable (continuous or not)
2006 Sep 22
2
"logistic" + "neg binomial" + ...
Hi Folks,
I've just come across a kind of problem which leads
me to wonder how to approach it in R.
Basically, each a set of items is subjected to a series
of "impacts" until it eventually "fails". The "force"
of each impact would depend on covariates X,Y say;
but as a result of preceding impacts an item would be
expected to have a "cumulative
2010 Feb 23
2
significance of coefficients in Constrained regression
I am fittting a linner regression with constrained parameters, saying, all
parameters are non-negative and sum up to 1.
I have searched historical R-help and found that this can be done by
solve.QP from the quadprog package. I need to assess the significance of the
coefficient estimates, but there is no standard error of the coefficient
estimates in the output. So I can not compute the p-value.
2008 Jul 23
3
Constrained coefficients in lm (correction)
Dear list,
In my previous email, the model I'd like to estimate is
rea=a*st+b*mod+error, where a+b=1 and a,b>0. My apologies for the
misunderstanding.
Thanks for all your help,
Jorge
On Wed, Jul 23, 2008 at 3:35 PM, Jorge Ivan Velez <jorgeivanvelez@gmail.com>
wrote:
>
> Dear list,
>
> I have a data set which looks like myDF (see below) and I'd like to
>
2005 May 12
1
Standardized logistic regression coefficients
Hi everyone,
how can I calculate standardized logistic regression coefficients using
R? I used "glm" resp. "lrm" from the design-package in order to
calculate logistic regression coefficients but I'm wondering if there's
a possibility to get standardized logistic regression coefficients?
Thanks in advance!
Alexander Roth
2010 Sep 10
1
Standardized logistic regression coefficients
Dear all,
I am looking for ways to compute standardized logistic regression coefficients. I found papers describing at least 6 different ways to standardize logistic regression coefficients. I also found a very old (Thu May 12 21:50:36 CEST 2005) suggestion by Frank E Harrell (one of the colleagues who frequently contribute on this list) saying...
Design doesn't implement those because they
2008 Oct 06
0
[LLVMdev] sext..to instruction
> I'm not sure about it, when sext to results a positve/negative value?
sext does signed-extension, zext does unsigned-extension.
This means that zext always extends by zero bits,
while with sext the additional bits are all copies of the
top bit of the original value. So with sext, if it was
negative in the original type when considered as a signed
value, then it will be negative in the
2010 Nov 13
1
Define a glm object with user-defined coefficients (logistic regression, family="binomial")
Hi there,
I just don't find the solution on the following problem. :(
Suppose I have a dataframe with two predictor variables (x1,x2) and one
depend binary variable (y). How is it possible to define a glm object
(family="binomial") with a user defined logistic function like p(y) =
exp(a + c1*x1 + c2*x2) where c1,c2 are the coefficents which I define.
So I would like to do no
2012 May 21
1
Complex text parsing task
Hello Everyone,
I have what I think is a complex text parsing task. I've provided some sample data below. There's a relatively simple version of the coding that needs to be done and a more complex version. If someone could help me out with either version, I'd greatly appreciate it.
Here are my sample data.
haveData <-
structure(list(profile_key = structure(c(1L, 1L, 2L, 2L, 2L,
2003 Jan 21
1
Logistic regression: At times correlation matrix of coefficients gets messed up
Hi,
When I include a categorical variable (RACE with 3 levels - "white",
"black" and "other") in my logistic regression model, the correlation
matrix of the coefficients gets messed up. I get something like:
-----------------------------------------
Correlation of Coefficients:
( A L RACEb
AGE , 1
LWT , 1
RACEblack 1
2008 Nov 07
1
ordinal logistic model with pre-defined coefficients
Hi,
I'm trying to fit a proportional ordinal logistic model using function
polr() (package MASS).
Is there a way to fix certain betas in the regression (e.g. function
arima() allows this by defining fixed )
Maybe there is another function than polr() which allows that?
Thanks
Kazys
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2012 May 31
3
How can I get this function to work?
Hello All,
Can anyone tell help me understand why the function below doesn't work and how I can fix it? Below are some sample data, some code that works on individual rows of the data, and my attempt to translate that code into a function. My hope is to get the function working and then to apply it to the larger data frame using ddply() from the plyr package or possibly some other approach.
2008 Jul 21
5
Coefficients of Logistic Regression from bootstrap - how to get them?
Hello all,
I am trying to optimize my logistic regression model by using bootstrap.
I was previously using SAS for this kind of tasks, but I am now
switching to R.
My data frame consists of 5 columns and has 109 rows. Each row is a
single record composed of the following values: Subject_name, numeric1,
numeric2, numeric3 and outcome (yes or no). All three numerics are used
to predict
2008 Jul 23
1
[Fwd: Re: Coefficients of Logistic Regression from bootstrap - how to get them?]
I think the argument supporting the use of bootstrap to determine
coefficients, as opposed to just running linear regression on the whole
dataset, is the comparison of Rsq and prediction errors between these
two approaches - page 1502. There's a substantial difference in favor of
the bootstrap approach.
--
Michal J. Figurski
Gustaf Rydevik wrote:
> The url for the mentioned paper is
2010 Feb 08
2
Counting by rows based on multiple criteria
Dear all,
I have a data frame of 6 columns and ~60000 rows which I hope to perform the following calculation on.
For each row, I wish to determine whether there are a greater number of positive or negative numbers. Then, if there are more positive numbers in the row, count how many occur - but if there are more negative numbers in the row, count them instead and insert a minus symbol before
2008 Dec 07
0
Generating output from auto.arima()
I have several hundred times series data sets and I am trying to use
auto.arima(), in the forecasting package, to take a first stab at fitting an
ARIMA model to each set. Ideally I would like to loop through each time
series use auto.arima() to fit a model and output the R^2 of the model and
the parameters.
I know how to fit each model but I am having trouble generating the
necessary output. I