Displaying 20 results from an estimated 10000 matches similar to: "Value at Risk historical simulation"
2013 Apr 04
5
Help for bootstrapping‏
I have a set of data for US t-bill returns and US stock returns frm 1980-2012. I am trying to bootstrap the data and obtain the minimum variance portfolio and repeat this portfolio 1000 times. However I am unable to get the correct code function for the minimum variance portfolio. When I tried to enter Opt(OriData+1, 1, 5, 0), I get "error:subscript out of bounds" Please help!
2005 Jan 07
2
Getting empirical percentiles for data
Dear List,
I have some discrete data and want to calculate the percentiles and the
percentile ranks for each of the unique scores. I can calculate the
percentiles with quantile().
I know that "ecdf" can be used to calculate the empirical cumulative
distribution. However, I don't know how to exact the cumulative
probabilities for each unique element. The requirement is similar
2011 Dec 23
3
data vector to corresonding percentile ranks
I have a problem where I need to calculate the corresponding cohort
percentile ranks for each of several variables.
Essentially, what I need is a function that will calculate the
distribution-free percentiles from each variable's data vector, returning a
corresponding vector of percentiles:
e.g.:
percentile.my.data<-/function/(my.data)
I tried to make ecdf() perform this task but
2004 Apr 06
2
percentile-percentile plot
Hi,
Is there a function that does percentile-percentile plot. I do not mean
the qqplot. I need to plot the percentiles rather than points themselves.
I am hoping for a plot that tells me that the x percentile of one data set
corresponds to the y percentile of the other. for example a point on the
plot of (.5, .2) will tell me that the 50th percentile of the first data
and the 20th percentile of
2011 Sep 28
1
Negative Quartile
Hello, I have a doubt, but it is more statistic than just about R: How
the people deal usually with negative percentile and quartile? In my
concrete case, I want to know the distribution of an error, so the
nearest it is to 0 the better (I think it would be optimun to have the
nearest values to 0 in the lower percentiles). The best result would
be making the percentile of the absolute value
2012 Jul 30
3
Calculating percentiles for multiple dates
I was hoping to calculate the percentile for each date. So group all of one
date together, calculating the value of the 2.5 and 97.5 percentile.
--
View this message in context: http://r.789695.n4.nabble.com/Calculating-percentiles-for-multiple-dates-tp4638183p4638378.html
Sent from the R help mailing list archive at Nabble.com.
2012 Nov 08
3
difference percentile R vs SPSS
Dear list,
I am calculating the 95th percentile of a set of values with R and with SPSS
In R:
> normal200<-rnorm(200,0,1)
> qnorm(0.95,mean=mean(normal200),sd=sd(normal200),lower.tail =TRUE)
[1] 1.84191
In SPSS, if I use the same 200 values and select Analyze -> Descriptive Statistics -> Frequencies
and under "Statistics", I type in '95' under Percentiles,
2009 Jan 08
2
VaR-Monte carlo Simulation, Historic simulation, Variance-Covariance Simulation
Dear R helpers
Suppose I have a portfolio of securities with exposure to Equity, Bonds and Forex (say $ 1000000 each).
Is there any fucntion in R that will help me calculate Value at Risk (VaR) using Monte carlo Simulation , Historic simulation and Variance - Covariance Simulation.
With regards
Maithili
2004 Apr 26
2
Looking for help in calculating percentiles
Hi All:
I am working with a dataset on Arsenic toxicity, and I am trying to
calculate the 20th, 40th, 60th, 80th, and highest percentiles for a
variable, dietary Moisture (variable name dMoist).
The inbuilt function quantile(dMoist) would print 0, 25th, 50th, 75th, and
100th percentile. Does there exist a function that can calculate xth
percentile (where x = 10th, 20th, ... etc) values?
2012 Apr 20
1
Package "demography" - calculating percentiles of survival probabilities distribution
Hi,
I am using the package "demography" from Rob Hyndman for the
Lee-Carter-Model. It is an amazing powerful tool but I am struggling with
one issue:
I want to compute different percentiles of the survival probability
distribution derived from the Lee-Carter-Forecast (e.g. the 50%tile,
60%tile, 75%tile and 99%tile) for each of the next 10 years. Is there any
possibility to retrieve
2004 Aug 31
4
More efficient matrix computation
I have a 20x3 matrix as follows:
> m <- replicate(3, matrix(rnorm(20),20,1))
I need to compute, say, 95th and 99th percentiles of
each column such that the resulting matrix becomes 2x3
with each row representing the respective percentile.
My "best effort" is to compute one column at a time as
follows:
> quantile(m[,1], c(0.95, 0.99))
To do the same for columns 2 and 3, I
2005 Oct 19
5
Range plots (lattice or base?)
I am looking to create what I would call a "simple variation" on the
boxplot. What I would like to do is to be able to plot the upper and
lower confidence limits as the "box" and the 10th and 90th percentile as
the whiskers. What I have done is write the code to create a dataframe,
the columns of which are the mean, sd, 10th percentile, 90th percentile,
lower confidence limit
2007 Jun 18
2
Calculating Percentile in R
Hi all,
I have a problem on how R calculates Percentiles :
Suppose I have following data set:
> data1
[1] -16648185 -14463457 -14449400 -13905309 -13443436 -13234755 -12956282 -11660896
[9] -10061040 -9805005 -9789583 -9754642 -9562164 -9391709 -9212182 -9151073
[17] -9092732 -9068214 -8978151 -8943912 -8761890 -8632106 -8541580 -8501249
[25] -8234466 -8219015
2004 Mar 10
1
accuracy of chi-square distribution approximations
Hi there,
How accurate is the aproximation R makes to the Chi-Square distribution?
For example, if I run:
> qchisq(1/1000000,6)
[1] 0.03650857
how accurate is 0.0365 compared to the theoretical percentile? What kind
of approximations have been made in the software's algorithm? It woudl be
useful to know since I am working with tiny percentiles such as one
one-millionth and one
2004 Sep 21
2
Ever see a stata import problem like this?
Greetings Everybody:
I generated a 1.2MB dta file based on the general social survey with
Stata8 for linux. The file can be re-opened with Stata, but when I bring
it into R, it says all the values are missing for most of the variables.
This dataset is called "morgen.dta" and I dropped a copy online in case
you are interested
http://www.ku.edu/~pauljohn/R/morgen.dta
looks like this
2017 Oct 10
2
small files performance
2017-10-10 8:25 GMT+02:00 Karan Sandha <ksandha at redhat.com>:
> Hi Gandalf,
>
> We have multiple tuning to do for small-files which decrease the time for
> negative lookups , meta-data caching, parallel readdir. Bumping the server
> and client event threads will help you out in increasing the small file
> performance.
>
> gluster v set <vol-name> group
2009 Apr 23
1
Loess over split data
Dear R users,
I am having trouble devising an efficient way to run a loess() function
on all columns of a data.frame (with the x factor remaining the same for
all columns) and I was hoping that someone here could help me fix my
code so that I won't have to resort to using a for loop.
(You'll find the upcoming lines of code in a single block near the end
of the message.)
Here's a
2009 Feb 17
6
Percentiles/Quantiles with Weighting
Hi All,
I am looking at applications of percentiles to time sequenced data. I had
just been using the quantile function to get percentiles over various
periods, but am more interested in if there is an accepted (and/or
R-implemented) method to apply weighting to the data so as to weigh recent
data more heavily.
I wrote the following function, but it seems quite inefficient, and not
really very
2017 Oct 10
0
small files performance
I just tried setting:
performance.parallel-readdir on
features.cache-invalidation on
features.cache-invalidation-timeout 600
performance.stat-prefetch
performance.cache-invalidation
performance.md-cache-timeout 600
network.inode-lru-limit 50000
performance.cache-invalidation on
and clients could not see their files with ls when accessing via a fuse
mount. The files and directories were there,
2011 May 25
3
how to compute the inverse percentile of a given observation w.r.t. a reference distribution
Hi,
can anyone help me to figure out how to compute the percentile of an
individual observation with respect to a reference distribution.
What I mean is. Let's assume I have a vector consisting of 10 numbers
{3,5,8,1,9,5,4,3,5.5,7} and I want figure out what percentile the
number 4.9 corresponds to. I failed to find any reference to such a
function, although I would assume this must