Displaying 20 results from an estimated 1000 matches similar to: "simulation study using R [SEC=UNCLASSIFIED]"
2006 Jun 30
1
Empirical CDF
Good day everyone,
I want to assess the error when fitting a Gram-Charlier
CDF to some data 'ws', that is, I want to calculate:
Err = |ecdf(ws) - GCh_ser(ws)|
The problem is, I cannot get the F(x) values from the
ecdf.
'Summary(ecdf())' returns some of the x-axis values,
but how do you get the F(x) values?
Thank you for any help you can provide.
Regards,
Augusto
2006 Jan 17
2
Calculation of daily max
Good day everyone.
I have a large dataset of 1 min wind speeds
covering 5 years.
How can I make an array of maximum daily values?
The vectors I have are: 'VDATE' with dates in format
'%Y-%m-%d' (like '1992-10-28') and 'WS' with wind speed data
(same number of elements as VDATE).
I want an array with 2 columns: Max daily wind speed and
corresponding day.
Has
2006 Jan 10
1
Interfacing with user in R
Good day everyone,
I am new in R programming (my question may sound
trivial to you): is there any way to ask the user
to enter a string within an R process, say a filename,
make R to recognise it and open the given file?
It is a simple exercise in other languages.
I am using R2.1.1 in a LINUX machine.
Thanks for your help.
Augusto
--------------------------------------------
Augusto
2007 Feb 23
2
Extracting a subset from a dataframe
Good day everyone,
Can anyone suggest an effective method to solve
the following problem:
I have 2 dataframes D1 and D2 as follows:
D1:
dates ws wc pwc
2005-10-19:12:00 10.8 80 81
2005-10-20:12:00 12.3 5 15
2005-10-21:15:00 12.3 3 15
2005-10-22:15:00 11.3 13 95
2005-10-23:12:00 12.3 13 2
2005-10-24:15:00 10.3 2 95
2005-10-25:15:00 10.3 2 2
D2:
2006 Jan 13
3
Saving a plot in R-LINUX
Good day,
Is there any way to save a plot produced by
R in a LINUX (Debian) machine?
The window opened by R to put the plot in,
does not give any option to save it (there
are options to move, close, minimise it, etc.
but not to save it). How do you do that?
Thanks,
Augusto
--------------------------------------------
Augusto Sanabria. MSc, PhD.
Mathematical Modeller
Risk Research Group
2006 Feb 02
3
15-min mean values
Good day everyone,
I want to use zoo(aggregate) to calculate
15-min mean values from a wind dataset which
has 1-min values. The data I have looks like this:
vector VDATE vector WS
1 1998-10-22:02:11 12.5
2 1998-10-22:02:12 10.1
3 1998-10-22:02:13 11.2
4 1998-10-22:02:14 10.5
5 1998-10-22:02:15 11.5
.
.
.
n
2006 Feb 22
1
Gram-Charlier series
Good day everyone,
I want to use the Gram-Charlier series expansion to model
some data. To do that, I need functions to:
1) Calculate 'n' moments from given data
2) Transform 'n' moments to 'n' central moments, or
3) Transform 'n' moments to 'n' cumulants
4) Calculate a number of Hermite polynomials
Are there R-functions to do any of the above?
2008 Mar 04
1
simulation study using R
Dear All,
I am running a Monte Carlo simulation study and have some questions on how
to manage data storage efficiently at the end of each 1000 replication loop.
I have three conditions coded using the FOR {} loops and a FOR loop that
generates data for each condition, performs analysis, and computes a
statistic 1000 times. Therefore, for each condition, I will have 1000
statistic values. My
2008 Mar 05
1
degrees of freedom extraction
Hello,
II used the logLik() function to get the log-likelihood estimate of an
object. The function also prints the degrees of freedom. How can I extract
the degrees of freedom and assign it to a variable.
Below is the output:
> logLik(fit2pl)
'log Lik.' -4842.912 (df=36)
Thanks,
Davood Tofighi
[[alternative HTML version deleted]]
2008 Mar 10
1
ltm package question
Hello All,
I was wondering how I can get the overall Pearson chi^2 test of model fit
with its df and p value in the LTM package for the 2PL models.
Thanks,
--
Davood Tofighi
Department of Psychology
Arizona State University
[[alternative HTML version deleted]]
2008 Mar 07
1
triple integral: adapt package question
Dear All,
I have a function f(x,y,z)=exp(x^3+y^4+x^2*y+x*z^2+y/z) over D, where is D={
(x,y,z)| 0 <z<Inf, 0<y<c1*z, 0<x<c2*/y}. x,y,z are all vectors and c1 and c2
are constants. I tried the "adapt" package and I get some error. This is the
error message:
"Error in function (z, y, x) : argument "x" is missing, with no default"
I included my R
2008 Mar 15
1
filehash
Hello,
I'm using filehash on the windows XP and it has been working fine with the
newest R version 2.6.2. However, on the windows vista, when I ran the same
code, I got the following error:
> dbCreate("simdb") #create simdb database
[1] TRUE
> db<-dbInit("simdb") #initiate an object of database
Error in sprintf(gettext(fmt, domain = domain), ...) :
object
2017 Aug 30
0
FW: Predictive accuracy measures in a recently released R package, spm: Spatial Predictive Modelling [SEC=UNCLASSIFIED]
Hi All,
Just thought you might be interested in a recently released R package, spm: Spatial Predictive Modelling.
It aims to introduce some novel, accurate, hybrid geostatistical and machine learning methods for spatial predictive modelling.
Of 22 functions available in spm, two functions are for accuracy assessment. Perhaps they are not only useful tools for spatial predictive modelling
2018 Apr 03
0
xgboost: problems with predictions for count data [SEC=UNCLASSIFIED]
Hi All,
I tried to use xgboost to model and predict count data. The predictions are however not as expected as shown below.
# sponge count data in library(spm)
library(spm)
data(sponge)
data(sponge.grid)
names(sponge)
[1] "easting" "northing" "sponge" "tpi3" "var7" "entro7" "bs34" "bs11"
2018 Mar 20
0
A new version (1.1.0) of the “spm” package for spatial predictive modelling reelased on CRAN [SEC=UNCLASSIFIED]
Dear R users,
A new version (1.1.0) of the ?spm? package for spatial predictive modelling is now available on CRAN.
The introductory vignette is available here:
https://cran.rstudio.com/web/packages/spm/vignettes/spm.html
There are several new enhancements to the package including a fast version of random forest in using ranger (rg) library(ranger) and the ability to convert relevant
2007 Sep 12
1
install R packages [SEC=UNCLASSIFIED]
Hi All,
I installed R 2.5.1 recently on a PC (Windows XP Professional 2001) and tried
to install some R packages. It took several minutes and gave me the following
message.
> utils:::menuInstallPkgs()
--- Please select a CRAN mirror for use in this session ---
Error in open.connection(file, "r") : unable to open connection
In addition: Warning message:
unable to connect to
2006 Mar 28
2
[Q] How to make a multi-line title with expression()
Dear R-lister
Could anyone know how to make a multi-line title for a plot with
expression()?
In my plot, the title should be writeen in two lines (because it is two long
for one line) and it should use a mathematical expression. I tried to use
"\n", but "\n" is ignored in expression() call:
hist(diffChangeRequestHintsBeforeAnswering[,4], br = 50, xlab = "Skill
Change in
2011 Jun 02
1
aucRoc in caret package [SEC=UNCLASSIFIED]
Hi all,
I used the following code and data to get auc values for two sets of predictions:
library(caret)
> table(predicted1, trainy)
trainy
hard soft
1 27 0
2 11 99
> aucRoc(roc(predicted1, trainy))
[1] 0.5
> table(predicted2, trainy)
trainy
hard soft
1 27 2
2 11 97
> aucRoc(roc(predicted2, trainy))
[1] 0.8451621
predicted1:
1 1 2
2006 Mar 10
2
Date and Times a la Dalgaard
Does anyone know of a resource for learning the basics of how to manage and
manipulate dates and times in R? I have been reading "Introductory
Statistics with R" by Peter Dalgaard which is fantastic. But alas, I could
find no reference to date and time. I have looked at the reference manual
but it is particularly unapproachable. So rather than dense technical talk I
would rather see a
2008 Dec 14
2
Help required to install package from a website
Hi,
I am new to R and I'm looking to perform some method comparison
analysis and would be grateful for some help regarding package
installation.
There is a package 'MethComp' that I want to use
(http://staff.pubhealth.ku.dk/~bxc/MethComp/Courses/Sthm.2007/.)
Unfortunately I am unable to install it. I have tried numerous
approaches but to no avail. this is the first time I have tried to