[R] Latin Hypercube with condition sum = 1
Rainer M Krug
r.m.krug at gmail.com
Sun Nov 23 18:59:29 CET 2008
On Sun, Nov 23, 2008 at 7:43 PM, Ben Bolker <bolker at ufl.edu> wrote:
> Rainer M Krug <r.m.krug <at> gmail.com> writes:
>
>>
>> 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
>>
>
> Perhaps I'm missing something, but it seems that there's
> only one vector that satisfies these two conditions simultaneously,
> which is x={0,1} ... ??? (Actually, technically speaking
> you could have as many zeros as you wanted -- x = {0,0,0,1}
> would also work -- but I don't think that's going to help much.)
> If min(x)=0 and max(x)=1, then x must contain 0 and 1. If x
> contains any other non-zero values, and no negative
> ones, then sum(x)>1 ...
You are absolutely right - but when you look at the example, I want
that the FINAL latin hypercube sets sum up to one, and the values
RANGING from 0 to 1, i.e. (0.5, 0.5) would also satisfy the condition.
>
> You seem to have a problem either in your definitions,
> or in your communication of those definitions to us ...
Probably both - but to try again:
1) values ranging between 0 and 1 (0 <= x <= 1)
2) all elements in one set of the lLatin Hypercube should add to one.
Assuming two dimensions, (1,0) & (0,1) & (0.3, 0.7) , ... would all
satisfy the condition 1 and 2;
(0.8, 0.3) would satisfy 1, but not 2;
(-1, 2) would satisfy 2, but not 1
Hope this clarifies my question,
Rainer
>
> cheers
> Ben Bolker
>
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--
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
Biology, UCT), Dipl. Phys. (Germany)
Centre of Excellence for Invasion Biology
Faculty of Science
Natural Sciences Building
Private Bag X1
University of Stellenbosch
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