[R] Latin Hyper cube with condition col1+ col2 < x

[Boris Steipe]

If you need h equal to 1, then replace any non-zero initial value of x[,b] with 1-x[,a].
But if you really need "less than", you'll need to specify what your desired distribution of h - x[,"a"] + x[,"b"] should look like.

No?


B.



On Oct 15, 2015, at 9:27 AM, Rainer M Krug <Rainer at krugs.de> wrote:

> Boris Steipe <boris.steipe at utoronto.ca> writes:
> 
>> I don't think the problem is well defined. Otherwise you could just
>> pick very small numbers from a range that is guaranteed to keep the
>> sum < h.
> 
> What further information is missing? That the variables should be
> covering the whole range from 0 to 1?
> 
> OK - forgotten to state that h <- 1.
> 
> This is for a sensitivity analysis which I want to conduct on a complex
> function.
> 
> Rainer
> 
> 
>> 
>> 
>> B.
>> 
>> On Oct 15, 2015, at 8:48 AM, Rainer M Krug <Rainer at krugs.de> wrote:
>> 
>>> Hi
>>> 
>>> I need a Latin Hypercube with the following conditions:
>>> 
>>> 0 < x[,"a"] < 1
>>> 0 < x[,"b"] < 1
>>> 0 < x[,"c"] < 1
>>> 
>>> but also
>>> 
>>> x[,"a"] + x[,"b"] < h
>>> 
>>> The first three are easy:
>>> 
>>> --8<---------------cut here---------------start------------->8---
>>> n <- 1000
>>> 
>>> lhc <- lhs::randomLHS(n=n, k=3
>>> colnames(lhc) <- c("a", "b", "c")
>>> 
>>> x <- lhc
>>> --8<---------------cut here---------------end--------------->8---
>>> 
>>> Now the last condition:
>>> 
>>> I tried
>>> 
>>> --8<---------------cut here---------------start------------->8---
>>> h <- 28
>>> x[,"a"] <- x[,"a"] / 2
>>> x[,"b"] <- x[,"b"] / 2
>>> --8<---------------cut here---------------end--------------->8---
>>> 
>>> But this obviously reduces the individual ranges.
>>> 
>>> Using the rowSum as in 
>>> https://stat.ethz.ch/pipermail/r-help/2013-October/361263.html
>>> 
>>> makes the sum of the variables also to 2.
>>> 
>>> So how can I create a Latin Hypercube which fulfills the conditions?
>>> 
>>> Rainer
>>> 
>>> -- 
>>> Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany)
>>> 
>>> Centre of Excellence for Invasion Biology
>>> Stellenbosch University
>>> South Africa
>>> 
>>> Tel :       +33 - (0)9 53 10 27 44
>>> Cell:       +33 - (0)6 85 62 59 98
>>> Fax :       +33 - (0)9 58 10 27 44
>>> 
>>> Fax (D):    +49 - (0)3 21 21 25 22 44
>>> 
>>> email:      Rainer at krugs.de
>>> 
>>> Skype:      RMkrug
>>> 
>>> PGP: 0x0F52F982
>>> ______________________________________________
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>> 
> 
> -- 
> Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany)
> 
> Centre of Excellence for Invasion Biology
> Stellenbosch University
> South Africa
> 
> Tel :       +33 - (0)9 53 10 27 44
> Cell:       +33 - (0)6 85 62 59 98
> Fax :       +33 - (0)9 58 10 27 44
> 
> Fax (D):    +49 - (0)3 21 21 25 22 44
> 
> email:      Rainer at krugs.de
> 
> Skype:      RMkrug
> 
> PGP: 0x0F52F982