Displaying 20 results from an estimated 900 matches similar to: "Hmisc improveProb() function"
2012 Nov 28
2
NRI or IDI for survival data - Hmisc package
Hi, I am trying to calculate net reclassification improvement (NRI) and Inegrated Discrimination Improvement (IDI) for a survival dataset to compare 2 risk models. It seems that the improveProb() in Hmisc package does this only for binary outcome, while rcorrp.cens() does take survival object, but doesn't output NRI or IDI. Can anyone suggest any other packages that can calculate NRI and IDI
2012 May 16
1
Hmisc improveProb() and PredictABEL reclassification () function and continuous NRI
Dear Sirs.
I am working with the R packages Hmisc and PredictABEL to make NRI estimates from my Cox models with and without a specific biomarker.
According to Pencina et al (Statistics in Medicine 2010, DOI: 0.1002/sim.4085 ), a continuous/non-categorical NRI (NRI>0) is to be used when there are no obvious reason to categorize risk, such as the risk of future cardiovascular events in patients
2009 Nov 09
1
ImproveProb Function in Design Package
Hello
Thanks to Frank Harrell for the great Design package. I noted from Pencina's Article (Statistics in Medicine Vol 27, pp157-172) that the result obtained for the Net Reclassification Index depends upon categorical cut-offs for risk (eg in the paper <6%, 6-20% and >20%). I wondered how the improveprob function arrives at its cut-offs, and whether there was any function to change the
2012 Dec 22
1
NRI reclassification table improveProb Cox
As describe in the Hmisc package's improveProb function, that function is for
binary Y. And it's best to use category-free methods.
Frank
Petergodsk wrote
> Hi
>
> I'm new to R.
>
> Is it possible to use the improveProb function to generate categorybased
> NRI using a Cox model?
> I believe I saw someone mentioning the possibility, but I can't find the
2012 Jan 17
2
net classification improvement?
Greetings,
I have generated several ROC curves and would like to compare the AUCs.
The data are cross sectional and the outcomes are binary. I am testing
which of several models provide the best discrimination. Would it be most
appropriate to report AUC with 95% CI's?
I have been looking in to the "net reclassification improvement" (see
below for reference) but thus far I can only
2012 Nov 07
2
R: net reclassification index after Cox survival analysis
Dear all,
I am interested to evaluate reclassification using net
reclassification improvement and Integrated Discrimination Index IDI after
survival analysis (Cox proportional hazards using stcox). I search a R
package or a R code that specifically addresses the categorical NRI for
time-to-event data in the presence of censored observation and, if
possible, at different follow-up time points.
I
2008 Jun 12
1
About Mcneil Hanley test for a portion of AUC!
Dear all
I am trying to compare the performances of several methods using the AUC0.1
and
not the whole AUC. (meaning I wanted to compare to AUC's whose x axis only
goes to
0.1 not 1)
I came to know about the Mcneil Hanley test from Bernardo Rangel Tura
and I referred to the original paper for the calculation of "r" which is an
argument of the function
cROC. I can only find the
2010 Jan 04
1
no "rcorrp.cens" in hmisc package
Dear,
I wanna to compare AUC generated by two distribution models using the same
sample.
I tried improveProb function's example code below.
set.seed(1)
library(survival)
x1 <- rnorm(400)
x2 <- x1 + rnorm(400)
d.time <- rexp(400) + (x1 - min(x1))
cens <- runif(400,.5,2)
death <- d.time <= cens
d.time <- pmin(d.time, cens)
rcorrp.cens(x1, x2, Surv(d.time, death))
2011 Oct 10
0
how to extent the improveProb for survival data
Dear R users
Function improveProb in the rms library calculate NRI and IDI for
predictions of binary outcome.
Do anyone extent its use in survival data?
Many thanks.
*Yao Zhu*
*Department of Urology
Fudan University Shanghai Cancer Center
Shanghai, China*
[[alternative HTML version deleted]]
2010 Jan 04
1
Are unpaired data suitable for Hmisc's improveProb ?
Dear,
I wanna to compare AUC generated by two distribution models using the same
sample.
The AUC for model 1 consists of two columns, column A for 0/1 and column B
for probability, eahc with the same row number of 3000.
The AUC for model 2 consists of two columns, column A for 0/1 and column B
for probability, eahc with the same row number of 10000 rows.
I am wondering what value I should put
2008 Jul 17
1
Comparing differences in AUC from 2 different models
Hi,
I would like to compare differences in AUC from 2 different models, glm and gam for predicting presence / absence. I know that in theory the model with a higher AUC is better, but what I am interested in is if statistically the increase in AUC from the glm model to the gam model is significant. I also read quite extensive discussions on the list about ROC and AUC but I still didn't find
2007 Mar 27
1
Jackknife estimates of predict.lda success rate
Dear all
I have used the lda and predict functions to classify a set of objects
of unknown origin. I would like to use a jackknife reclassification to
assess the degree to which the outcomes deviate from that expected by
chance. However, I can't find any function that allows me to do this.
Any suggestions of how to generate the jackknife reclassification to
assess classification accuracy?
2012 Aug 15
2
store the results of two connected and "disturbed" for-loops to data.frame
Dear all,
here is a example of my problem:
/#data#
g<-c(1,1,1,2,2,2)
A<-runif(6,min=1,max=5)
B<-runif(6,min=100,max=1000)
C<-runif(6,min=30,max=31)
D<-runif(6,min=67,max=98765)
var<-cbind(A,B,C,D)
label<-colnames(var)
store<-data.frame(matrix(ncol=2))
colnames(store)=c("usedVar","prediction")
library(MASS)#get lda
for (i in c(1:4))
{
for (k in
2001 Aug 04
1
replacing elements in matrix: fastest method?
Hi!
I replace some elements of a matrix a
> a
[,1] [,2] [,3]
[1,] 1 2 3
[2,] 4 5 6
[3,] 7 8 9
[4,] 10 11 12
according to a reclassification matrix such
> pares
[,1] [,2]
[1,] 1 2
[2,] 5 6
[3,] 8 7
to get
> b
[,1] [,2] [,3]
[1,] 1 2 3
[2,] 4 5 6
[3,] 7 8 9
[4,] 10 11 12
As both a and
2010 Jan 04
1
Are unpaired data suitable for DiagnosisMed's Diagnosis ?
Dear,
I wanna to compare AUC generated by two distribution models using the same
sample.
The AUC for model 1 consists of two columns, column A for 0/1 and column B
for probability, eahc with the same row number of 3000.
The AUC for model 2 consists of two columns, column A for 0/1 and column B
for probability, eahc with the same row number of 10000 rows.
I am wondering what value I should put
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
2018 Apr 18
1
R Bug: write.table for matrix of more than 2, 147, 483, 648 elements
Hi Colton,
You could divide your write task into chunks that do not violate the 2^31-1 limit.
write.table has an append argument (default FALSE).
Figure out a row chunk size nri < nr such that nri * nc is under 2^31-1 and use
write.table() to write that out.
Then use
write.table( append = TRUE, )
for the next chunk of rows, looping over chunks until done. Two chunks will get your 2.8
2016 Jun 09
4
rsync keeps writing files over
Hi Steven,
Yes, both file systems are the same.
rsync -nri --modify-window=1 <src> <dest>
Gives me the following for most files >f..T.......
2015_167_1_1__Boy_What_A_Girl_R2/2015_167_1_1__Boy_What_A_Girl__UHD_DPX_R2/
BWAG_R2_00138428.dpx
Although a few have >f..T......n
2015_167_1_1__Boy_What_A_Girl_R2/2015_167_1_1__Boy_What_A_Girl__UHD_DPX_R2/
BWAG_R2_00135909.dpx
2003 Aug 12
4
rsync problem
Hi all,
I've installed rsync-2.5.6 on a sun box (solaris 8). When I run rsync using the
command
rsync -a ssh /opt/local/pkgs/httpd/htdocs/ root@remotemachine:/mnt/
I get the error
rsync: connection unexpectedly closed (0 bytes read so far)
rsync error: error in rsync protocol data stream (code 12) at io.c(165)
What could be the reason? Any help would be appreciated.
Thanks,
Rajesh.
2007 Sep 29
3
plugin problem
I'm trying to do a rewrite of the dspam_plugin for dovecot 1.1b1.
There are some API changes that warranted an update of the plugin.
Also, I wanted the dspam_plugin to be able to handle pristine mails
for dspam retraining, as opposed to the signature based retraining.
Question:
How can I retrieve the full unix path for a specific mail?
The original code uses mail_get_first_header() to