Displaying 20 results from an estimated 31 matches for "laranjeira".
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laranjeiras
2004 Sep 06
4
Cox regression for prevalence estimates
Hello, I'm an MD working in an eye clinic. I'm learning by myself to use R
for use in my research works and for implementation in a software project.
There are some authors who recomends the use of Cox regression as a
substitute for Logistic regression (<a
href="http://www.biomedcentral.com/1471-2288/3/21.pdf"> Barros AJD, Hirakata
VN. BMCMedical Research Methodology, 2003;
2006 Sep 24
2
plotCI
...)
ciw.f<-sqrt(1.766073e-08)
plotCI(ano,rf,uiw=ciw.f)
But in the graph not shown the errors bar and I have this error msg
zero-length arrow is of indeterminate angle and so skipped
Well, where is my eror?
Thanks in advance
Bernardo Rangel Tura, MD, PhD
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
2003 May 01
3
Test statistic for Spearman correlation
In the ouput below, what is the "S" statistic (S = 96) that is used for Spearman? I don't have easy access to the books cited on the help page. Other texts and web sources that I have found use t or z as a test for Spearman, perhaps inappropriately. Can anyone tell me how S is computed or refer to a web resource?
I see from the code for that:
q <- as.integer((n^3 - n) * (1
2005 Aug 30
1
loglinear model selection
...NA
Now I need fit a loglinear model with this variables, but I need know have
a command with generate ALL models with the set this 8 vairables (ALL minus
[,8]) incluindind the interactions.
Can Anyone Help me?
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
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2004 Dec 15
3
(no subject)
Dear R-helper,
I would like to compare the AUC of two logistic regression models (same
population). Is it possible with R ?
Thank you
Roman Rouzier
[[alternative HTML version deleted]]
2004 Jan 09
2
Fit non-linear regressor
...2,57,62,67,72,77,82)
I need fit R and A in y=f(x)=R*exp(A*x), with minimize sd= sqrt(SRR/(n-2)) where SRR is Sum of the Square of the Residuals
and n is number of data points (in this case 10)
How do I make this?
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
2005 Mar 18
2
logistic model cross validation resolved
This post is NOT a question, but an answer. For readers please disregard all earlier posts by myself about this question.
I'm posting for two reasons. First to say thanks, especially to Dimitris, for suggesting the use of errorest in the ipred library. Second, so that the solution to this problem is in the archives in case it gets asked again.
If one wants to run a k-fold cross-validation
2006 Dec 03
4
prop.trend.test issue
I have the clinical study data.
Year 0 Year 3
Retinol (nmol/L) N Mean +-sd Mean +-sd
Vitamin A group 73 1.89+-0.36 2.06+-0.53
Trace group 57 1.83+-0.31 1.78+-0.30
where N is the number of male for the clinical study.
I want to test if the mean serum retinol has increased over 3 years
among subjects in the vitamin A group.
> 1.89+0.36
2002 Nov 13
4
[Newbie] Is there any support for work with grouped frequencies?
Hi,
I have this table (BTW, published by FBI and representing age
distribution of the WTC tragedy victims):
"LABEL" "FREQ" "MIDPOINT"
"1" "Infant (under 1)" 0
"2" "1 to 4" 5
"3" "5 to 8" 1
"4" "9 to 12" 3
"5" "13 to 16" 0
"6" "17 to
2003 Nov 27
2
MASS fitdistr()
Dear R experts,
I am trying to use the R MASS library fitdistr() to fit the following
list:
k21stsList<-c(0.76697,0.57642,0.75938,0.82616,0.93706,0.77377,0.58923,0.37157,0.60796,1.00070,0.97529,0.62858,0.63504,0.68697,0.61714,0.75227,1.16390,0.66702,0.83578)
as follows,
library(MASS)
fitdistr(k21stsList, "normal")
But, I get
Error in fitdistr(k21stsList, "normal") :
2004 Jan 14
1
NLS mensagem error...
...Error in nls(X2000 ~ R * exp(A * age), start = list(R = 0.1, A = 0.1)) :
singular gradient
In addition: Warning message:
no finite arguments to min; returning Inf
How I fix this problem? Other command?
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
2004 Feb 06
0
multiple plots in different windows
...ts (in
>different windows) ?
Hi
I think wich the correct code is:
>for(i in 1:L) {
>windows()
> plot(listOfFunctions[[i]])
>}
This work in my computer.
I dont know thje answer for your second question
Best wishes
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
2004 Feb 09
0
Fit system of equations
...t) = base mortality on year t
b(x,t) = exponential rate of mortality for age x on year t
b(t) = exponential rate of mortality on year t
I wish is possible fit this system in R?
Case positive Which the best method?
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
2004 Sep 07
2
noncommutative addition: NA+NaN != NaN+NA
Hi guys.
Check this out:
> NaN +NA
[1] NaN
> NA + NaN
[1] NA
I thought "+" was commutative by definition. What's going on?
> R.version
_
platform powerpc-apple-darwin6.8
arch powerpc
os darwin6.8
system powerpc, darwin6.8
status
major 1
minor 9.0
year 2004
month 04
day 12
language R
>
(Both give NA under linux, so it looks
2005 Mar 12
1
Database reorganization
...9 15
7 11 20
future data base
year age x
1980 1 5
1980 3 7
1980 5 9
1980 7 11
1981 1 8
1981 3 9
1981 5 15
1981 7 20
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
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2005 May 17
0
Problem in lme longitudinal model
...08 7 138
8 1.1902613 8 115
9 0.9619330 9 92
10 0.7037427 10 69
11 0.8591257 11 46
12 1.2215657 12 23
Well
I need help for solution this problem....
Somebody can help me?
Thanks in advance
Bernardo Rangel Tura, MD, MSc
National Institute of Cardiology Laranjeiras
Rio de Janeiro Brazil
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2005 Sep 05
2
Fisher's method in discriminant analysis
Hi,
I'm using mda library to solve a discriminant
analysis. I get results, but the thing is that I want
to use Fisher's method to obtain the classification
functions and I'm lost in what I should do: libraries
to use, ... Can anybody give me a clue??
Thanks.
Carlos Niharra L??pez
2006 Mar 02
2
How can I use r-cran-lmtest?
Hi,
I installed the package r-cran-lmtest in a Debian Sid but I can't use it. I typed "lmtest" but nothing occur.
Any help?
Thanks.
--
S?vio Martins Ramos - Arquiteto
Rio de Janeiro ICQ 174972645
Pirataria n?o! Seja livre: Linux
http://www.debian.org
2004 Dec 29
3
gls model and matrix operations
Dear List:
I am estimating a gls model and am having to make some rather unconventional modifications to handle a particular problem I have identified. My aim is to fit a GLS with an AR1 structure, obtain the variance-covariance matrix (V), modify it as needed given my research problem, and then reestimate the GLS by brute force using matrix operations. All seems to be working almost perfectly,
2002 Jul 01
1
chi square residuals
dear list,
I'm a newbie with R but it seems very interesting to me.
First, to train myself and students, I'd like to use it for teaching labs next
year.
one of my labs deals with the barn owl predation in my region. tudents have to
work on a contingency table tytogrp :
station1 station2 station3 ...
n1,1 n1,2 n1,3 ...
n2,1 n2,2 n2,3 ...