Hi Folks,
I'm trying to learn R. One of my intentions is to do some Monte-Carlo
type modelling of road accidents.
Below, to simplify things, I've appended a little program which does a
'monte-carlo' type simulation. However, it is written in a way which
seems a bit un-natural in R. Could
1. I suggest you avoid using c as a loop index, as it conflicts
with the name of a function. R is smart enough to figure out the
difference in some cases but not in all.
2. How about the following:
n - 900
x - runif(n)
y - runif(n)
z - sqrt(x^2+y^2)
print(list(Overwork.ratio =
For this particular problem you can probably use
polar coordinates.
But something similar to your code could be:
x - runif(900)
y - runif(900)
z - sqrt(x^2 + y^2)
okay - z 1
while(any(!okay)) {
n.bad - sum(!okay)
x[!okay] - runif(n.bad)
y[!okay] - runif(n.bad)
z - sqrt(x^2 + y^2) #
On Wed, Oct 15, 2003 at 10:06:36AM +0100, Sean O'Riordain wrote:
n - 900; # number of valid items required...
x - numeric(n);
y - numeric(n);
z - numeric(n);
c - 1; # current 'array' pointer
tc - 0; # total items actually looked at...
while (c = n) {
x[c] = runif(1, 0, 1);
Hi Patrick, Spencer,
Thanks for that! Both your solutions are MUCH quicker!
afaik overwork_ratio = 4/pi # what a hard way to calculate this :-)
The real problem I'm actually working on is a little more complicated
:-) - 6 'random' variables, and 18 dependant variables (at last
count)...
