R help - Mar 2013 - help on writing a function

Dear All
 
If you could please help me with a solution on the following:
we have:
 
a <-matrix(c(1,2,3,4,5))
x <-matrix(c(0.3,0.2,0.1,0.08,0.05))
b <-50*exp(-x[1]*a[1])
d <-b*exp(-x[2]*a[2])
e <-d*exp(-x[3]*a[3])
f <-e*exp(-x[4]*a[4])
g <-f*exp(-x[5]*a[5])
 
I would like to be able to calculate g with fewer steps, thought perhaps a
function could do that?
 
I apreciate your help,
 
thanks
 
Andras
	[[alternative HTML version deleted]]

Hello,

Try this one liner.

g2 <- 50 * prod(exp(-x*a))
identical(g, g2)  # TRUE


Hope this helps,

Rui Barradas

Em 23-03-2013 11:27, Andras Farkas escreveu:
> Dear All
>
> If you could please help me with a solution on the following:
> we have:
>
> a <-matrix(c(1,2,3,4,5))
> x <-matrix(c(0.3,0.2,0.1,0.08,0.05))
> b <-50*exp(-x[1]*a[1])
> d <-b*exp(-x[2]*a[2])
> e <-d*exp(-x[3]*a[3])
> f <-e*exp(-x[4]*a[4])
> g <-f*exp(-x[5]*a[5])
>
> I would like to be able to calculate g with fewer steps, thought perhaps a
function could do that?
>
> I apreciate your help,
>
> thanks
>
> Andras
> 	[[alternative HTML version deleted]]
>
>
>
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