[R] Help: a matrix exponential

[Daniel Malter]

This is a matrix algebra problem, not an R problem. ej fails because
betaligne and ZIcolone are not conformable matrices.

dim(betaligne)
1 2

dim(ZIcolone)
76  1

Let a matrix be m x n, then you can only matrix multiply it with a matrix
that is n x k (where m and k are arbitrary positive integers, but n must be
the same). The resulting matrix will be m x k. So you can postmultiply
t(betaligne) with t(ZIcolone) or ZIcolone with betaligne. Everything else is
not conformable.

HTH,
Daniel



> 
> Hi,
> 
>> I have a problem with the final results fj   ;
>>fj must firstly be a vector indexed by j = 8, and the same avoire Chifre
(9.5),
> 
>>> beta0=64.91151
>> beta1=17.70393
>> beta=c(beta0, beta1)
>> j=1:8
>> n=76
>> i=1:n
>> zi<-c(26, 26, 26, 28, 28, 28, 28, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30,
>> 30, 30, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 34,
>> 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34, 34,
>> 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 36, 38, 38, 38,
>> 38, 38, 38, 38, 38)
>> Xi<-c(5.79, 1579.52, 2323.7, 68.85, 426.07, 110.29, 108.29, 1067.6,
>> 17.05, 22.66, 21.02, 175.88, 139.07, 144.12, 20.46, 43.4, 194.9, 47.3,
>> 7.74, 0.4, 82.85, 9.88, 89.29, 215.1, 2.75, 0.79, 15.93, 3.91, 0.27,
>> 0.69, 100.58, 27.8, 13.95, 53.24, 0.96, 4.15, 0.19, 0.78, 8.01, 31.75,
>> 7.35, 6.5, 8.27, 33.91, 32.52, 3.16, 4.85, 2.78, 4.67, 1.31, 12.06,
>> 36.71, 72.89, 1.97, 0.59, 2.58, 1.69, 2.71, 25.5, 0.35, 0.99, 3.99, 3.67,
>> 2.07, 0.96, 5.35, 2.9, 13.77, 0.47, 0.73, 1.4, 0.74, 0.39, 1.13, 0.09,
>> 2.38)
>> ZI<-log(zi)
>> betaligne<-t(as.matrix(-beta))
>>   ZIcolone<-as.matrix(ZI)
>> k=8
>> ej<-1/k*sum(exp(betaligne %*% ZIcolone)*Xi)
> Error in betaligne %*% ZIcolone : non-conformable arguments
>>
> 
> PLEASE HELP ME
> THANKS 
> Goual
> 




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