Quite true Jim, however I focused on his request and not his code,
presuming that he did not realize what he was doing as a consequence
of the nested loops.
Perhaps Alexandre can provide clarification?
Regards,
Marc
On Jun 18, 2009, at 2:46 PM, jim holtman wrote:
That is not what his 'for' loops are doing. He is iterating through
all
combinations and would have created 784. So his problem statement
did not
match the code that he sent.
On Thu, Jun 18, 2009 at 2:12 PM, Marc Schwartz
<marc_schwa...@me.com> wrote:
Alexandre did say 28 datasets, not 784 (28 * 28)....
Thus, either:
mapply(rnorm, n = 500, mean = a1, sd = a2)
or
apply(cbind(a1, a2), 1, function(x) rnorm(500, x[1], x[2]))
HTH,
Marc Schwartz
On Jun 18, 2009, at 12:51 PM, Henrique Dallazuanna wrote:
Try this also:
a <- expand.grid(a1, a2)
x <- mapply(rnorm, n = 500, mean = a[,1], sd = a[,2])
On Thu, Jun 18, 2009 at 2:10 PM, Alexandre Lockhart <
alexandre_geor...@hotmail.com> wrote:
Hello:
My problem is that I have a data frame of means, and a data frame
of
standard deviations which match up to each mean. I have been
trying to
create 500 random numbers in a given dataset for each mean/sd
combination,
but I am only able to generate the last value in each data set to
create
one
dataset (there should be 28 in all). Examining my code, what can I
change
to generate 28 datasets based on respective mean and sds?
a1<-
c
(178.07,178.28,178.08,177.74,177.04,178.17,177.58,57.71,59.6,60.92,59.48,59.32,61.59,59.94,28.9,29.82,30.73,25.68,27.93,28.98,29.76,123.48,127.27,127.8,127.2,127.13,126.71,125.5
)
a2<-
c
(1.69,1.3,1
,.
18,1.53,1.31,1.35,1.83,1.56,1.12
,.
74,1.48,1.67,1.53
,.95,.87,0.03,1.12,1.95,1.22,1.04,1.64,1.83,1,1,1.08,1.35,2.37)
for(i in 1:length(a1))
for(j in 1:length(a2))
x<-rnorm(500,mean=a1[i],sd=a2[j])
Thank you,
Agl
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