Displaying 20 results from an estimated 10000 matches similar to: "Tree() and confidence intervals"
2004 May 30
0
Application of tree() to get alternative confidence bounds - is this feasible?
> Hello
>
> I'm currently using Monte Carlo techniques to estimate prices (variable not static) from the following type of data:
>
> << OLE Object: Microsoft Excel Worksheet >>
>
>
>
> Each row is a record from group A and the cells in all but the last column are the volumes of 'widgets' in the record. The last column is the cost of all
2017 Aug 16
1
Bias-corrected percentile confidence intervals
Hi folks,
I'm trying to estimate bias-corrected percentile (BCP) confidence
intervals on a vector from a simple for loop used for resampling. I am
attempting to follow steps in Manly, B. 1998. Randomization, bootstrap
and monte carlo methods in biology. 2nd edition., p. 48. PDF of the
approach/steps should be available here:
https://wyocoopunit.box.com/s/9vm4vgmbx5h7um809bvg6u7wr392v6i9
If
2012 Nov 13
1
Confidence intervals in Ripley's K function - a little challenge...
I have plotted Ripley's K function for a spatial point pattern for 12 plots,
with 39 Monte Carlo simulations for complete spatial randomness (CSR).
I would like to analyse these data as follows:
I would like to know for which plots the Ripley's K function deviates from
CSR at a number of confidence intervals, namely 90%, 95% and 99%.
I realise that simulation envelope I have produced
2004 Aug 19
3
Do you know if you can map a large minimum spanning tree in R?
Thanks Mike.
My data has longitude and latitude coords and I used distAB {clim.pact}
then mst {ape} to calculate my minimum spanning tree. The nodes are
telecoms sites from all over Australia. My goal is to determine the
minimum cost of linking them via cabling, and I'm starting by
calculating the distance "as the crow flies", but will probably
eventually need to calculate the
2012 Jun 22
1
Variance with confidence interval
Hi,
Is there a way to calculate variance directly by specifying
confidence interval using R ? I am specifically asking because I wanted
to investigate how this could be useful for project schedule variance
calculation.
Moreover I am interested in using R for monte carlo simulation as well
and any simple examples would help. I read that project schedules would
benefit from this.
2005 Jul 08
3
How do you sort a data frame on a selection of columns?
This is what to start with:
Data Frame A B C D
c1 4 y 5
c3 6 d 7
c1 5 t 6
Now sort on A then C
This is what to end with:
Data Frame A B C D
c1 5 t 6
c1 4 y 5
c3 6 d 7
I assume it is something like this:
attach(DF)
sort(DF,partial=c(A,C))
Thanks in advance.
Meredith
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2005 Aug 02
6
can we manage memory usage to increase speed?
Hi,
Thanks for reading.
I am running a process in R for microarray data analysis. RedHat Enterprise Linux 4, dual AMD CPU, 6G memory. However, the R process use only a total of <200M memory. And the CPU usage is total to ~110% for two. The program takes at least 2 weeks to run at the current speed. Is there some way we can increase the usage of CPUs and memories and speed up? Any
2005 Apr 15
2
Help with "MERGE" gratefully accepted
Hello
How do I use function 'MERGE" to combine the FILE A and FILE B below to make FILE C?
Thank you
FILE A
140 151 167
30.1 11.4 40
FILE B
140 167
5.7 30.3
FILE C
140 151 167
30.1 11.4 40
5.7 NA 30.3
2004 Jun 01
3
Confidence Bounds on QQ Plots?
What's the current best wisdom on how to construct confidence
bounds on something like a normal probability plot?
I recall having read a suggestion to Monte Carlo something like
201 simulated lines with the same number of points, then sort the order
statistics, and plot the 6th and 196th of these. [I use 201 not 200
because quantile(1:201, c(0.025, 0.975)) = 6 and 196 while
2004 Feb 05
2
Histograms by two factors
Hi
I am trying to print out means, STDs and histograms under two sets of factors. I can manage it for one set - see below but not for two sets. That is, I want ot print out the mean STD and Histogram for each ITEM code within each DELIVERABLE code. In addition I can only get to view the histogram for the last item. How do you get R to stop overriding the histogram for eg level 1 for factor 1
2004 Aug 03
1
How does R vary from SAS?
Hello
I have to show that R has more functionality than SAS for MonteCarlo type exercises involving matrix algebra. As I has little experience with SAS is anyone able to help. I have a model written in R but the IT world in this company is not familiar with R and wants to use something like SAS.
thanks
2013 Mar 27
1
Conditional CCA and Monte Carlo - Help!
Hi All,
I am using canonical correspondence analysis to compare a community
composition matrix to a matrix of sample spatial relationships and
environmental variables. In order to parse out how much variance is
explained purely by space (S/E) or the environment (E/S) I am using a
conditional (partial) CCA. I want to test significance via Monte Carlo but
I can not find a way to do this with a
2016 Sep 26
2
Publication & Project: Verificarlo: checking floating point accuracy through Monte Carlo Arithmetic
Hi,
We have recently published a paper on floating point accuracy analysis
through Monte Carlo Arithmetic. We also released the open-source tool
Verificarlo (https://github.com/verificarlo/verificarlo) that relies on
LLVM for instrumenting floating point operations.
Could you please add our paper to http://llvm.org/pubs/ ?
Verificarlo: checking floating point accuracy through Monte Carlo
2004 Mar 09
1
bug(?) in chisq.test
This is a message for whoever maintains "chisq.test": For an
outcome more extreme than 2000 simulations, a Monte Carlo p-value of "<
2.2e-16" was printed. Ripley said the proper p-value for such cases
should be 1/(B+1) = 1/2001. This can be easily fixed by adding
"if(PVAL==0)PVAL <- 1/(B+1)" right after the following line in the code
for chisq.test (in R
2012 Mar 22
0
New package RcppSMC 0.1.0 for Sequential Monte Carlo and Particle Filters
===== Summary =====
Version 0.1.0 provides the initial release of RcppSMC, an integration of the
SMCTC template classes for Sequential Monte Carlo and Particle Filters
(Johansen, 2009, J Statistical Software, 30:6) with the Rcpp package for R/C++
Integration (Eddelbuettel and Francois, 2011, J Statistical Software, 40:8).
RcppSMC allows for easier and more direct access from R to the
2012 Mar 22
0
New package RcppSMC 0.1.0 for Sequential Monte Carlo and Particle Filters
===== Summary =====
Version 0.1.0 provides the initial release of RcppSMC, an integration of the
SMCTC template classes for Sequential Monte Carlo and Particle Filters
(Johansen, 2009, J Statistical Software, 30:6) with the Rcpp package for R/C++
Integration (Eddelbuettel and Francois, 2011, J Statistical Software, 40:8).
RcppSMC allows for easier and more direct access from R to the
2007 Jan 26
1
bootstrap bca confidence intervals for large number of statistics in one model; library("boot")
Sometimes one might like to obtain pointwise bootstrap bias-corrected,
accelerated (BCA) confidence intervals for a large number of statistics
computed from a single dataset. For instance, one might like to get
(so as to plot graphically) bootstrap confidence bands for the fitted
values in a regression model.
(Example: Chiu S et al., Early Acceleration of Head Circumference in
Children with
2010 Mar 29
1
generating samples by Monte Carlo
Hello Dear,
I am trying to generate samples by using Monte Carlo simulation. For
example,
1000 samples, Exponential distribution (f(x), lambda=0.0005, 0<=x<=360)
Is there any package for Monte Carlo or just use random sample generation
function?
Many thank you for your help in advance,
Jin
--
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2007 Jun 06
0
R package: Mchtest - Monte Carlo hypothesis testing allowing Sequential Stopping
Hi,
This is an announcement for a package that has been up on CRAN since March 2006 but was never announced.
The package is Mchtest - for Monte Carlo hypothesis tests allowing sequential stopping. The idea is to use the sequential probability ratio test boundaries to stop resampling for a Monte Carlo hypothesis test such as a bootstrap or permutation test. This means that you will take many
2007 Jun 06
0
R package: Mchtest - Monte Carlo hypothesis testing allowing Sequential Stopping
Hi,
This is an announcement for a package that has been up on CRAN since March 2006 but was never announced.
The package is Mchtest - for Monte Carlo hypothesis tests allowing sequential stopping. The idea is to use the sequential probability ratio test boundaries to stop resampling for a Monte Carlo hypothesis test such as a bootstrap or permutation test. This means that you will take many