When I look at this line:
f4 <- pars[1]*pars[2]*pars[3](pars[1]+pars[4])
It appears to my wet-brain interpreter that you are trying to apply a
function par[3] to the argument (pars[1]+pars[4])
When I insert a "*", I then get output but I don't know if it is
correct.
> newton.input2(pars)
$fval
[1] 46.00 3956.00 6181.25 4439.00
$jacobian
[,1] [,2] [,3] [,4]
[1,] 40 1.15 0 0e+00
[2,] 5280 197.80 0 0e+00
[3,] 8250 247.25 0 0e+00
[4,] 6160 126950.00 101560 1e+05
--
David
On Jan 20, 2010, at 4:58 AM, Roslina Zakaria wrote:
Hi r-users,
I have the following code to solve 4 simultaneous eqns with 4
unknowns using newton iteration method. But I got the error message:
pars <- c(1.15, 40, 50, 0.78)
newton.input2 <- function(pars)
{ ## parameters to estimate
alp <- pars[1]
b1 <- pars[2]
b2 <- pars[3]
rho <- pars[4]
f1 <- pars[1]*pars[2]
f2 <- pars[1]*(pars[1]+1)*pars[2]^2
f3 <- pars[1]*(pars[1]+1)*pars[3]^2
f4 <- pars[1]*pars[2]*pars[3](pars[1]+pars[4])
fval <- c(f1,f2,f3,f4)
## jacobian matrix
j11 <- pars[2]
j12 <- pars[1]
j13 <- 0
j14 <- 0
j21 <- (2*pars[1]+1)*pars[2]^2
j22 <- 2*pars[2]*pars[1]*(pars[1]+1)
j23 <- 0
j24 <- 0
j31 <- (2*pars[1]+1)*pars[3]^2
j32 <- 2*pars[3]*pars[1]*(pars[1]+1)
j33 <- 0
j34 <- 0
j41 <- pars[2]*pars[3]*(2*pars[1]+pars[4])
j42 <- pars[3]*(pars[3]^2+pars[3]*pars[4])
j43 <- pars[2]*(pars[3]^2+pars[3]*pars[4])
j44 <- pars[3]*pars[2]*pars[3]
jacobian <-
matrix
(c
(j11
,j12
,j13
,j14
,j21,j22,j23,j24,j31,j32,j33,j34,j41,j42,j43,j44),byrow=TRUE,ncol=4)
## output
list(fval=fval,jacobian=jacobian)
}
newton.input2(pars)
newt(newton.input2, c(1,20,30,0.5))
Note: I use 'newt' code is develope by Rolf Turner.
Thank you.
Error message:
newton.input2(pars)
Error in newton.input2(pars) : attempt to apply non-function
newt(newton.input2, c(1,20,30,0.5))
Error in fn(p.o, ...) : attempt to apply non-function
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
