Displaying 20 results from an estimated 300 matches similar to: "delete-d jackknife"
2008 Dec 18
1
using jackknife in linear models
Hi R-experts,
I want to use the jackknife function from the bootstrap package onto a
linear model.
I can't figure out how to do that. The manual says the following:
# To jackknife functions of more complex data structures,
# write theta so that its argument x
# is the set of observation numbers
# and simply pass as data to jackknife the vector 1,2,..n.
# For example, to jackknife
#
2012 Nov 14
2
Jackknife in Logistic Regression
Dear R friends
I´m interested into apply a Jackknife analysis to in order to quantify the
uncertainty of my coefficients estimated by the logistic regression. I´m
using a glm(family=’binomial’) because my independent variable is in 0 - 1
format.
My dataset has 76000 obs, and I´m using 7 independent variables plus an
offset. The idea involves to split the data in let’s say 5 random subsets
and
2003 Apr 16
2
Jackknife and rpart
Hi,
First, thanks to those who helped me see my gross misunderstanding of
randomForest. I worked through a baging tutorial and now understand the
"many tree" approach. However, it is not what I want to do! My bagged
errors are accpetable but I need to use the actual tree and need a single
tree application.
I am using rpart for a classification tree but am interested in a more
unbaised
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?
2010 Nov 14
2
jackknife-after-bootstrap
Hi dear all,
Can someone help me about detection of outliers using jackknife after
bootstrap algorithm?
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2005 Nov 08
1
Poisson/negbin followed by jackknife
Folks,
Thanks for the help with the hier.part analysis. All the problems
stemmed from an import problem which was solved with file.chose().
Now that I have the variables that I'd like to use I need to run some
GLM models. I think I have that part under control but I'd like to use
a jackknife approach to model validation (I was using a hold out sample
but this seems to have fallen out
2006 Apr 11
4
Bootstrap and Jackknife Bias using Survey Package
Dear R users,
I?m student of Master in Statistic and Data analysis, in New University of Lisbon. And now i?m writting my dissertation in variance estimation.So i?m using Survey Package to compute the principal estimators and theirs variances.
My data is from Incoming and Expendire Survey. This is stratified Multi-stage Survey care out by National Statistic Institute of Mozambique. My domain of
2006 Oct 24
1
Variance Component/ICC Confidence Intervals via Bootstrap or Jackknife
I'm using the lme function in nmle to estimate the variance components
of a fully nested two-level model:
Y_ijk = mu + a_i + b_j(i) + e_k(j(i))
lme computes estimates of the variances for a, b, and e, call them v_a,
v_b, and v_e, and I can use the intervals function to get confidence
intervals. My understanding is that these intervals are probably not
that robust plus I need intervals on the
2004 Mar 02
0
Jackknife after bootstrap influence values in boot package?
Is there a routine in the boot package to get the jackknife-after-
bootstrap influence values? That is, the influence values of
a jackknife of the bootstrap estimates?
I can see how one would go about it from the jack.after.boot code, but that
routine only makes pretty pictures.
It wouldn't be hard to write, but I find it hard to believe this
isn't part of the package already.
Thanks
2012 Mar 04
0
Jackknife for a 2-sample dispersion test
Hi All,
I'm not able to figure out how to perform a Jackknife test for a 2-sample
dispersion test in R. Is there a built-in function to perform this or do we
have to take a step by step approach to calculate the test statistic?
Any help would be awesome.
Thanks!
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2007 Dec 31
0
Optimize jackknife code
Hi,
I have the following jackknife code which is much slower than my colleagues C code. Yet I like R very much and wonder how R experts would optimize this.
I think that the for (i in 1:N_B) part is bad because Rprof() said sum() is called very often but I have no idea how to optimize it.
#O <- read.table("foo.dat")$V1
O <- runif(100000);
k=100 # size of block to delete
2005 May 11
1
Mixed Effect Model - Jackknife error estimate
Greetings,
I?ve fit the following mixed effects model using the NLME package:
hd.impute.lme <- lme(I(log(HEIGHT_M - 1.37)) ~ SPECIES + SPECIES:I(1/(DBH_CM + 2.54)),
random = ~ I(1/(DBH_CM + 2.54)) | PLOTID,
data = trees, na.action = na.exclude)
I would now like to extract a jackknife estimate of model error. I tried the following code, however, the estimate produced seems too
2011 Apr 19
1
How to Extract Information from SIMEX Output
Below is a SIMEX object that was generated with the "simex" function from the
"simex" package applied to a logistic regression fit. From this mountain of
information I would like to extract all of the values summarized in this
line:
.. ..$ variance.jackknife: num [1:5, 1:4] 1.684 1.144 0.85 0.624 0.519 ...
Can someone suggest how to go about doing this? I can extract the
2011 May 18
1
Help with Memory Problems (cannot allocate vector of size)
While doing pls I found the following problem
> BHPLS1 <- plsr(GroupingList ~ PCIList, ncomp = 10, data = PLSdata, jackknife =
>FALSE, validation = "LOO")
when not enabling jackknife the command works fine, but when trying to enable
jackknife i get the following error.
>BHPLS1 <- plsr(GroupingList ~ PCIList, ncomp = 10, data = PLSdata, jackknife =
>TRUE,
2010 Feb 10
2
Total least squares linear regression
Dear all,
After a thorough research, I still find myself unable to find a function
that does linear regression of 2 vectors of data using the "total least
squares", also called "orthogonal regression" (see :
http://en.wikipedia.org/wiki/Total_least_squares) instead of the
"ordinary least squares" method. Indeed, the "lm" function has a
2011 Aug 21
3
pooled hazard model with aftreg and time-dependent variables
Dear R-users,
I have two samples with individuals that are in more than one of the samples
and individuals that are only in one sample. I have been trying to do a
pooled hazard model, stacking one sample below the other, with aftreg and
time-dependent covariates. The idea behind is to see aggregate effects of
covariates, but need to control for ther effects of same individuals in both
samples
2003 Jan 15
1
Is R really an open source S+ ?
This is not a criticism. I'm just curious. Is there an effort to keep R
comparable to S+?
Or are the two languages diverging? I am doing what probably legions have
done before me,
and legions will after me...using R on examples from text books written with
S+ code. Most of the
time everything appears to be equivalent. And then there are amazing
divergences in commands. For
instance:
S:
2007 Sep 19
3
Robust or Sandwich estimates in lmer2
Dear R-Users:
I am trying to find the robust (or sandwich) estimates of the standard error of fixed effects parameter estimates using the package "lmer2". In model-1, I used "robust=TRUE" on the other, in model-2, I used "robust=FALSE". Both models giving me the same estimates. So my question is, does the robust option works in lmer2 to get the robust estimates of
2004 Apr 12
2
Complex sample variances
Hello,
Is there a way to get complex sample variances in the survey package on summary statistics other than means? If not, can they be added to a future version? It would be be great to have them on totals, quantiles, ratios, and tables (eg row percent, columns percent, etc).
Thanks.
Fred
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2011 May 17
1
Help with PLSR with jack knife
Hi
I am analysing a dataset of 40 samples each with 90,000 intensity measures for
various peptides. I am trying to identify the Biomarkers (i.e. most significant
peptides). I beleive that PLS with jack knifing, or alternativeley
CMV(cross-model-validation) are multivariateThe 40 samples belong to four
different groups.
I have managed to conduct the plsr using the commands:
BHPLS1 <-