Displaying 20 results from an estimated 3000 matches similar to: "Rank of factors for experiment based on latin hypercube?"
2017 Aug 04
2
Latin hypercube sampling from a non-uniform distribution
Hello,
I am performing a sensitivity analysis using a Latin Hypercube sampling. However, I have difficulty to draw a Hypercube sample for one variable. I?ve generated this variable from a Poisson distribution as follows:
set.seed(5)
mortality_probability <- round(ppois(seq(0, 7, by = 1), lambda = 0.9), 2)
barplot(mortality_probability, names.arg = seq(0, 7, by = 1), xlab = "Age
2011 Sep 09
1
conditional Latin hypercube sampling
Hello,
I got one question on the Latin hypercube sampling.
suppose
there are three variables a, b, c, all of them follow the normal
distribution. the mean value and standard deviation for each areĀ a(32,
2), b(35,5), c(37,3). I would like to use Latin hypercube sampling to
random generate 1000 samples. but it needs to satisfy the condition that
a<b<c.
How can I implement this
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
2017 Jun 01
0
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
I think you should take this conversation private or seek local
statistical expertise. This is about strategies for analysis, not
about programming in R.
Cheers,
Bert
Bert Gunter
"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Wed, May 31, 2017 at
2012 Jun 20
2
Conditioned Latin Hypercube Sampling within determined distance
Hi all,
I am a begginer in R and I have been trying to use the Conditioned Latin
Hypercube to choose sample points only in areas close to roads due to the
difficult thorough access in the study area. I could use a code to create
the points throughout the area, but I need to create a code to make the R
only comes up with points close to this road. I've been using the packages
2013 Feb 19
1
latin hypercube sampling
Hi all,
I am attempting to use latin hypercube sampling to sample different
variable functions in a series of simultaneous differential equations.
There is very little code online about lhs or clhs, so from different
other help threads I have seen, it seems I need to create a
probability density function for each variable function, and then use
latin hypercube sampling on this pdf.
So far, I
2017 Aug 08
1
Latin hypercube sampling from a non-uniform distribution
Thanks for your answer.
I have attached the plot for representing the variable. I think that I need to draw a Hypercube sample for each age class (i.e., for 0, 1, 2, 3, 4, 5, 6, 7) in a given simulation (i.e., N = 1) and the LHS values for all age classes should be like the observed cumulative distribution (see attached figure). Thus, the output of randomLHS should be a matrix with 100 rows (N =
2017 Aug 07
2
Latin hypercube sampling from a non-uniform distribution
Thanks for your answer.
However, my variable is simulated from the cumulative distribution function of the Poisson distribution. So, the pattern obtained from the function "qpois" is not the same as the observed pattern (i.e., obtained from the function "ppois")
set.seed(5)
mortality_probability <- round(ppois(seq(0, 7, by = 1), lambda = 0.9), 2)
2008 Nov 23
2
Latin Hypercube with condition sum = 1
Hi
I want to du a sensitivity analysis using Latin Hypercubes. But my
parameters have to fulfill two conditions:
1) ranging from 0 to 1
2) have to sum up to 1
So far I am using the lhs package and am doing the following:
library(lhs)
ws <- improvedLHS(1000, 7)
wsSums <- rowSums(ws)
wss <- ws / wsSums
but I think I can't do that, as after the normalization
> min(wss)
[1]
2017 Aug 07
0
Latin hypercube sampling from a non-uniform distribution
> How can I draw a Hypercube sample for the variable mortality_probability so
> that this variable exhibits the same pattern as the observed distribution?
One simple way is to use the uniform random output of randomLHS as input to the quantile function for your desired distribution(s).
For example:
q <- randomLHS(1000, 3)
colnames(q) <- c("A", "B",
2003 Feb 20
0
Latin Hypercube Sampling in R?
Hi,
I am interested in using R to perform Monte Carlo simulation using MC
sampling, Latin Hypercube Sampling (LHS), and importance sampling. While
I'm sure I can code R to do LHS, I would be surprised if others had not
done so. Is there R code publically available for this purpose? (I have
searched CRAN and the WWW extensively with no luck). Thanks in
advance.
Dan Loughlin
2011 May 31
2
Latin Hypercube Sampling with a condition
Hello all,
I am trying to do a Latin Hypercube Sampling (LHS) to a 5-parameter
design matrix. I start as follows:
library(lhs)
p1<-randomLHS(1000, 5)
If I check the distribution of each parameter (column), they are
perfectly uniformly distributed (as expected).For example,
hist(p1[,1])
Now the hard (maybe strange) question. I want the combination of the
first three parameters to sum up to
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
2017 Jun 01
1
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
Thank you very much Rob for your answer. I have some difficulties to understand how to apply my agent-based model to each parameter combination generated by the LHS, in particular when parameters are defined by probability distributions. Indeed, I have multiple parameters in my model: parameters which are defined by a single value (like ?temperature", "pressure?) and parameters which are
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
2017 May 27
2
Latin Hypercube Sampling when parameters are defined according to specific probability distributions
>May 26, 2017; 11:41am Nelly Reduan Latin Hypercube Sampling when parameters are >defined according to specific probability distributions
>Hello,
> I would like to perform a sensitivity analysis using a Latin Hypercube Sampling (LHS).
>Among the input parameters in the model, I have a parameter dispersal distance which is defined according to an exponential probability
2013 Oct 08
3
Latin Hypercube Sample and transformation to uniformly distributed integers or classes
Hi,
I'd like to use Latin Hypercube Sampling (LHC) in the the context of
uncertainty / sensitivity analysis of a complex model with approximately 10
input variables. With the LHC approach I'd like to generate parameter
combinations for my model input variables.
Therefore I came across an simple example here on the mailing list (
2017 Aug 08
0
Latin hypercube sampling from a non-uniform distribution
> However, my variable is simulated from the cumulative distribution function
> of the Poisson distribution.
Then I am afraid I don't know what you're trying to achieve.
Or why.
However, the principle holds; write a function that maps [0,1] to the 'pattern' you want, do that and apply it to the result from randomLHS.
It happens that for generating data that follow a given
2009 Mar 02
1
Large data set in R
Hello,
I'm trying to use R statistical packages to do ANOVA analysis using aov() and lm().
I'm having a problem when I have a large data set for input data from Full Factorial Design Experiment with replications.
R seems to store everything in the memory and it fails when memory is not enough to hold the massive computation.
Have anyone successfully used R to do such analysis before? Are
2010 Feb 08
3
Hypercube in R
Dear all,
Does anybody have an idea or suggestion how to construct (plot)
4-dimensional hypercube in R.
Thanks in advance for any pointers.
Regards, Andrej
2009 Apr 28
1
Bounded memory ANOVA
Hi,
I'm using aov() to analyze the data and get the rank of factors. However, this does not work for larger set of data due to memory limitation.
Are there any similar function to use aov() on data sets larger than memory similar to biglm ?
Thanks,
~ Hardi
2007 Jan 22
1
Latin hyper cube sampling from expand.grid()
Dear R experts
I am looking for a package which gives me latin hyper cube samples
from the grid of values produced from the command "expand.grid". Any
pointers to this issue might be very useful. Basically, I am doing the
following:
> a<-(1:10)
> b<-(20:30)
> dataGrid<-expand.grid(a,b)
Now, is there a way to use this "dataGrid" in the package
2007 Dec 05
2
converting factors to dummy variables
Hi all -
I'm trying to find a way to create dummy variables from factors in a
regression. I have been using biglm along the lines of
ff <- log(Price) ~ factor(Colour):factor(Store) +
factor(DummyVar):factor(Colour):factor(Store)
lm1 <- biglm(ff, data=my.dataset)
but because there are lots of colours (>100) and lots of stores
(>250), I run it to memory problems. Now, not every