[R] Matrix multiplication and random numbers

[RFish]

Dear All

I new to using R and am struggling with some matrix multiplication. 

I have two matrices, one containing random numbers, these are multiplied
together to get another matrix which is different each time. When I put in
another for loop to repeat this process a multiple times the matrices are
all the same. I’m sure there is a way to keep the randomness of the
different matrices but I think I’m putting the for loop in the wrong place.
Also when I try and save the matrices using write.table only the first one
is saved

The code so far is below, any help would be greatly appreciated 

Cheers

Tom     

InitialPop<-matrix(c(500,0,0,0,0,0,0))

matmult<-function(InitialPop,N){
mat3<-matrix(c(0,rnorm(1,0.6021,0.0987),0,0,0,0,0,0,0,rnorm(1,0.6021,0.0987),0,0,0,0,1.9,0,0,rnorm(1,0.6021,0.0987),0,0,0,4.8,0,0,0,rnorm(1,0.6021,0.0987),0,0,9.7,0,0,0,0,rnorm(1,0.6021,0.0987),0,18,0,0,0,0,0,rnorm(1,0.6021,0.0987),32.6,0,0,0,0,0,0),nrow=7)

for (i in 1:N){
PVAmatrix<-matrix(c(0,rnorm(1,0.6021,0.0987),0,0,0,0,0,0,0,rnorm(1,0.6021,0.0987),0,0,0,0,1.9,0,0,rnorm(1,0.6021,0.0987),0,0,0,4.8,0,0,0,rnorm(1,0.6021,0.0987),0,0,9.7,0,0,0,0,rnorm(1,0.6021,0.0987),0,18,0,0,0,0,0,rnorm(1,0.6021,0.0987),32.6,0,0,0,0,0,0),nrow=7)
mat3<-mat3%*%PVAmatrix
}

ans<-mat3 %*% InitialPop

return(ans)

}

z<-matmult(InitialPop,1)
for (i in 1:4) print(z[,1])
write.table((z),"c:\\Documents and Settings\\...........................) 

-- 
View this message in context: http://www.nabble.com/Matrix-multiplication-and-random-numbers-tp25365184p25365184.html
Sent from the R help mailing list archive at Nabble.com.