How to append the random no.s for different variables in the same data.frame

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
project.org] On Behalf Of PIKAL Petr
Sent: Wednesday, September 12, 2012 10:49 AM
To: Vincy Pyne
Cc: r-help
Subject: Re: [R] How to append the random no.s for different variables
in the same data.frame

Hi

It is good to cc to R help. It would be even better if you provide toy
data to illustrate what do you have and what do you want. Sometimes you
will find solution when preparing such data yourself without need for
posting to the rhelp.

I am still not sure what do you really want to achieve so below are
some points



From: Vincy Pyne [mailto:vincy_pyne at yahoo.ca]
Sent: Wednesday, September 12, 2012 10:09 AM
To: PIKAL Petr
Subject: How to append the random no.s for different variables in the
same data.frame


Dear Mr Petr Sir,

I sincerely apologize to you for taking the liberty of writing to you.
I thank you for your valuable solution you have given. However, I am
missing some point and request you to please guide me if possible. I am
giving my original R code below.

#
.......................................................................
..............

library(plyr)

ead_mc = function(product, output_avg, output_stdev)


     {

product_usage_borrowing_room_mc = rnorm(n, output_avg, output_stdev)

Here you create random numbers with some mean and sd # I need to store
these random no.s for all products in a single data frame.

product_usage_borrowing_room_mc_filtered1 <-
subset(product_usage_borrowing_room_mc, product_usage_borrowing_room_mc

0)

product_usage_borrowing_room_mc_filtered <-
subset(product_usage_borrowing_room_mc_filtered1,
product_usage_borrowing_room_mc_filtered1 <= 100)

Here you drop values over 100 and below 0 Why don't you use runif(n,
0,100)?
Anyway, I still am rather in doubt what do you want to achieve further.
Without knowing how your data look like it is really difficult to
provide some help.
What was wrong on the code I suggested to you? Here is some
modification based on information snippets from your mail.
mydf <-data.frame(product = rep(letters[1:3], each=10))
mydf$monte<-1
mydf$monte<-unlist(lapply(split(mydf$monte, mydf$product), function(x)
rnorm(x, 10, 10))) selection <- mydf$monte>0&mydf$monte<=100
mydf_filt<-mydf[selection, ] mydf_filt$m<-ave(mydf_filt$monte,
mydf_filt$product, FUN=mean) mydf_filt$sd<-ave(mydf_filt$monte,
mydf_filt$product, FUN=sd)
head(mydf_filt)
  product     monte        m       sd
1       a  3.978948 12.83564 7.240065
2       a 16.889179 12.83564 7.240065
3       a 13.062089 12.83564 7.240065
4       a 12.458633 12.83564 7.240065
5       a 23.495197 12.83564 7.240065
7       a  3.291643 12.83564 7.240065
Gives you one data frame with column of random numbers between 0 and
100 and column of means and sd for each product.
Is this what do you want? If not, please elaborate on such toy data
what do you have and what do you want as a result.
Regards
Petr
selection <- product_usage_borrowing_room_mc > 0 &
product_usage_borrowing_room_mc <= 100
product_usage_borrowing_room_mc_filtered <-
product_usage_borrowing_room_mc[selection , ] output_avg_mc =
mean(product_usage_borrowing_room_mc_filtered)
output_stdev_mc = sd(product_usage_borrowing_room_mc_filtered)

product_usage_borrowing_room_mc_filtered_sorted =
sort(product_usage_borrowing_room_mc_filtered, decreasing = FALSE)

ead_monte_carlo =
product_usage_borrowing_room_mc_filtered_sorted[alpha*length(product_us
age_borrowing_room_mc_filtered_sorted)]

return(list(output_avg_mc, output_stdev_mc, ead_monte_carlo))

   }

result <- dlply(.data = filtered_new, .variables = "product", .fun =
function(x)
          ead_mc(product = x$product, output_avg = x$output_avg,
output_stdev = x$output_stdev))



# End of Code

# ---------------------------------------------------------------

In the first line of function, I have used

product_usage_borrowing_room_mc = rnorm(n, output_avg, output_stdev)

So when for a given product this loop (i.e. function) is run, a new set
of random no.s is stored.

My return statement gives me a different required output which is my
main requirement.

Simply put, when the loop is run, I need to store the random no.s in a
single data.frame for all products.

Sir, I once again apologize for taking this liberty of writing to you.
The attached zip file gives the R code and related input files if in
case you will like to see.

Thanking you and will certainly appreciate if you kindly guide me.

With warm regards

Vincy





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