Re: [R] random number generation

[Michael Dewey]

Dear Leila

Does the function mvrnorm in package MASS do what you want?

On 11/11/2015 08:38, leila zamani via R-help wrote:

Hi every one,
I'm new to R. I read about R and search all the packages but I couldn't find 
the package that I want. I want to generate 2D (matrices) random numbers that 
have correlation between them. One of my friends said that R has a function in 
geor like rand...(spherical (correlation coefficient=0.5)), but I read all 
packages with geo,like geor,geoRlgm,georob and etc, but I didn't find this! Can 
you help me? Thanks.


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Re: [R] random number generation

[Karim Mezhoud]

Hi,
This generate matrix:
matrix( rnorm(5*4,mean=0,sd=1), 5, 4)

for correlated matrix please see this link:
http://stackoverflow.com/questions/10680658/how-can-i-create-a-correlation-matrix-in-r
Karim


On Wed, Nov 11, 2015 at 9:38 AM, leila zamani via R-help <
r-help@r-project.org> wrote:

> Hi every one,
> I'm new to R. I read about R and search all the packages but I couldn't
> find the package that I want. I want to generate 2D (matrices) random
> numbers that have correlation between them. One of my friends said that R
> has a function in geor like rand...(spherical (correlation
> coefficient=0.5)), but I read all packages with geo,like
> geor,geoRlgm,georob and etc, but I didn't find this! Can you help me?
> Thanks.
>
>
> [[alternative HTML version deleted]]
>
> __
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

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[R] random number generation

[leila zamani via R-help]

Hi every one,
I'm new to R. I read about R and search all the packages but I couldn't find 
the package that I want. I want to generate 2D (matrices) random numbers that 
have correlation between them. One of my friends said that R has a function in 
geor like rand...(spherical (correlation coefficient=0.5)), but I read all 
packages with geo,like geor,geoRlgm,georob and etc, but I didn't find this! Can 
you help me? Thanks.


[[alternative HTML version deleted]]

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Re: [R] Random number generation

[Daniel Nordlund]

 -Original Message-
 From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org]
 On Behalf Of Dennis Murphy
 Sent: Thursday, July 21, 2011 8:55 PM
 To: karena
 Cc: r-help@r-project.org
 Subject: Re: [R] Random number generation
 
 Hi:
 
 Here's one way using uniform(0, 1) pseudo-random numbers, but there
 are many ways you could go about this.
 
 # each row comprises a set of three pseudo-random numbers
 u - matrix(runif(30), nrow = 10)
 # divide each element in a row by its row sum
 v - t(apply(u, 1, function(x) x/sum(x)))
 rowSums(v)
  [1] 1 1 1 1 1 1 1 1 1 1
 
 # An equivalent way (about equally fast) is
 u/outer(rowSums(u), rep(1, 3))
 
 Now try
 
 hist(unlist(v))
 
 and notice that the distribution of the constrained sets is not really
 uniform. This is a consequence of setting a constraint on the sum of
 each sample. Another way to see this is to plot
 
 plot(sort(unlist(v)))
 
 A 'truly' uniform random sample would lie approximately on a straight
 line in this plot.
 
 It would seem to me that a better approach would be to sample from a
 simplex embedded in the unit cube. I'd suggest looking into the
 compositions package (because you are effectively generating
 compositional data) and look into its capabilities. At least a couple
 of the references in the package's overview page seem to be germane to
 the problem.
 The pair of runif.* functions appear to be relevant.
 
 HTH,
 Dennis
 
 
 
 On Thu, Jul 21, 2011 at 4:18 PM, karena dr.jz...@gmail.com wrote:
  Hi,
 
  I want to generate multiple sets of random numbers.
  The requirement is that:
  1) each set have 3 random numbers;
  2) the sum of the three number is always 1.
 
  how to do this?
 
  thank you,
 
  karena
 

Karena,

if you search the R-help archive you will find a couple of threads discussing 
this topic.  Here is one URL to get you started.

  http://tolstoy.newcastle.edu.au/R/e2/help/06/10/2520.html

Hope this is helpful,

Dan

Daniel Nordlund
Bothell, WA USA

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Re: [R] Random number generation

[karena]

Thank you guys for all the help. I appreciate!

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[R] Random number generation

[karena]

Hi, 

I want to generate multiple sets of random numbers.
The requirement is that:
1) each set have 3 random numbers;
2) the sum of the three number is always 1.

how to do this?

thank you,

karena

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Re: [R] Random number generation

[Jason Edgecombe]

On 07/21/2011 07:18 PM, karena wrote:

Hi,

I want to generate multiple sets of random numbers.
The requirement is that:
1) each set have 3 random numbers;
2) the sum of the three number is always 1.

how to do this?


Try this:

df-data.frame(a=runif(10),b=runif(10))
df$c=df$a+df$b
df

Replace 10 with the number of rows that you want. Replace runif with 
your random function of choice.


Jason

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Re: [R] Random number generation

[Jason Edgecombe]

On 07/21/2011 08:04 PM, Jason Edgecombe wrote:

On 07/21/2011 07:18 PM, karena wrote:

Hi,

I want to generate multiple sets of random numbers.
The requirement is that:
1) each set have 3 random numbers;
2) the sum of the three number is always 1.

how to do this?


Try this:

df-data.frame(a=runif(10),b=runif(10))
df$c=df$a+df$b
df

Replace 10 with the number of rows that you want. Replace runif with 
your random function of choice.


Jason

Nevermind, I didn't address how to ensure that each row adds up to one.

Sorry,
Jason

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Re: [R] Random number generation

[Duncan Murdoch]

On 21/07/2011 7:18 PM, karena wrote:

Hi,

I want to generate multiple sets of random numbers.
The requirement is that:
1) each set have 3 random numbers;
2) the sum of the three number is always 1.

how to do this?


There are lots of ways.  What is the context?  It would determine the 
first two steps:


1.  Generate A.
2.  Generate B.
3.  C - 1-A-B

Duncan Murdoch

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Re: [R] Random number generation

[Rolf Turner]

Could this possibly be a homework question?

cheers,

Rolf Turner

On 22/07/11 11:18, karena wrote:

Hi,

I want to generate multiple sets of random numbers.
The requirement is that:
1) each set have 3 random numbers;
2) the sum of the three number is always 1.

how to do this?


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Re: [R] Random number generation

[karena]

To Jason: Still thank you, your reply gives me some clue about how to do
this. 

To Duncan: Thank you for rely. It helped.

Karena

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Re: [R] Random number generation

[Dennis Murphy]

Hi:

Here's one way using uniform(0, 1) pseudo-random numbers, but there
are many ways you could go about this.

# each row comprises a set of three pseudo-random numbers
u - matrix(runif(30), nrow = 10)
# divide each element in a row by its row sum
v - t(apply(u, 1, function(x) x/sum(x)))
rowSums(v)
 [1] 1 1 1 1 1 1 1 1 1 1

# An equivalent way (about equally fast) is
u/outer(rowSums(u), rep(1, 3))

Now try

hist(unlist(v))

and notice that the distribution of the constrained sets is not really
uniform. This is a consequence of setting a constraint on the sum of
each sample. Another way to see this is to plot

plot(sort(unlist(v)))

A 'truly' uniform random sample would lie approximately on a straight
line in this plot.

It would seem to me that a better approach would be to sample from a
simplex embedded in the unit cube. I'd suggest looking into the
compositions package (because you are effectively generating
compositional data) and look into its capabilities. At least a couple
of the references in the package's overview page seem to be germane to
the problem.
The pair of runif.* functions appear to be relevant.

HTH,
Dennis



On Thu, Jul 21, 2011 at 4:18 PM, karena dr.jz...@gmail.com wrote:
 Hi,

 I want to generate multiple sets of random numbers.
 The requirement is that:
 1) each set have 3 random numbers;
 2) the sum of the three number is always 1.

 how to do this?

 thank you,

 karena

 --
 View this message in context: 
 http://r.789695.n4.nabble.com/Random-number-generation-tp3685463p3685463.html
 Sent from the R help mailing list archive at Nabble.com.

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.


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[R] Random Number Generation in a Loop

[Maithili Shiva]

Dear R helpers
 
I am having following data
 
Name   Numbers
A  25
B   3  
C  13
A   5  
B   7
C   0
A   2 
B 10 
C   9
 
CONDITIONS
 
If Name is A, min_val = 1.05, max_val = 1.30
If Name is B, min_val = 1.30, max_val = 1.60
If Name is C, min_val = 1.60, max_val = 1.99
 
TASK
 
To generate the Uniform random nos for each of these Names (Equal to the 
corresponding no. e.g. the 5th Name is B, so I need to generate 7 uniform 
random numbers in the range (1.30 - 1.99). Also I need to arrange these random 
numbers one by one in a single csv file i.e. say 25 random numbers in teh range 
(1.05-1.30) followed by 3 random numbers in the range (1.30-1.60) and so on.
 
# ___ 
 
Here is the R code I have tried
 
ONS - read.table(textConnection(name number  
A11    12   
A12    17   
A13 0   
A11    11    
A12  6 
A13  0 
A11  8
A12  4 
A13  3), header = TRUE)
 
X = as.character(ONS$name)
Y = ONS$number
 
Z = NULL
 
for (i in 1:length(X))
   {
   if(X[i] == 'A11')
   {
   min_val = 1.05
   max_val = 1.30
   Z = runif(Y[i], min_val, max_val)   
   }
   else
   {
   if(X[i] == 'A12')
   {
   min_val = 1.30
   max_val = 1.60
   Z = runif(Y[i], min_val, max_val)   
   }
   else
   {
   if(X[i] == 'A13')
   {
   min_val = 1.60
   max_val = 1.99
   Z = runif(Y[i], min_val, max_val)   
   }
   }
   }
   }
 
# End of Code
 
## _
 
PROBLEM
 
I need to get 61 random numbers which is total of all the numbers (1st 12 fo A, 
3 random numbers for B, 13 for C, 5 again fo A and so on). The result whcih I 
got is
 
 Z
[1] 1.740443 1.761758 1.797222
 
which is pertaining to the last name C where 3 random numbers are generated 
i.e. Z instaed of getting added, is overwritten.
 
Please help me to rectify my code so that in the end I will get 61 random 
numbers as desired i.e. 12 for A in the range (1.05 - 1.30), 3 for B in the 
range (1.30 - 1.60), 13 for C in the range (1.60-1.99), again 5 for A in the 
range (1.05 - 1.30).
 
Thanking in advance. I also sincerely apologize for writing such a long mail, 
as I wanted to be clear as possible in my communication.
 
Regards
 
Maithili
 
 


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Re: [R] Random Number Generation in a Loop

[Daniel Malter]

Hi, does this do what you want to do? I take the first six lines of the data
you provided. Note that letters corresponds to your Name, and number
corresponds to your Numbers variable.

letters=rep(c(A,B,C),2)
letters

number=c(25,3,13,5,7,0)
number

letters2=rep(letters,number)
letters2

interval.min=ifelse(letters2==A,1.05,ifelse(letters2==B,1.3,1.6))
interval.max=ifelse(letters2==A,1.3,ifelse(letters2==B,1.6,1.99))

rand.nums=runif(letters2,min=interval.min,max=interval.max)

data.frame(letters2,rand.nums)

HTH,
Daniel

-
cuncta stricte discussurus
-
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
Behalf Of Maithili Shiva
Sent: Thursday, December 17, 2009 1:25 AM
To: r-help@r-project.org
Subject: [R] Random Number Generation in a Loop


Dear R helpers
 
I am having following data
 
Name   Numbers
A  25
B   3  
C  13
A   5  
B   7
C   0
A   2 
B 10 
C   9
 
CONDITIONS
 
If Name is A, min_val = 1.05, max_val = 1.30 If Name is B, min_val = 1.30,
max_val = 1.60 If Name is C, min_val = 1.60, max_val = 1.99
 
TASK
 
To generate the Uniform random nos for each of these Names (Equal to the
corresponding no. e.g. the 5th Name is B, so I need to generate 7 uniform
random numbers in the range (1.30 - 1.99). Also I need to arrange these
random numbers one by one in a single csv file i.e. say 25 random numbers in
teh range (1.05-1.30) followed by 3 random numbers in the range (1.30-1.60)
and so on.
 
# ___ 
 
Here is the R code I have tried
 
ONS - read.table(textConnection(name number  
A1112   
A1217   
A13 0   
A1111
A12  6 
A13  0 
A11  8
A12  4 
A13  3), header = TRUE)
 
X = as.character(ONS$name)
Y = ONS$number
 
Z = NULL
 
for (i in 1:length(X))
   {
   if(X[i] == 'A11')
   {
   min_val = 1.05
   max_val = 1.30
   Z = runif(Y[i], min_val, max_val)   
   }
   else
   {
   if(X[i] == 'A12')
   {
   min_val = 1.30
   max_val = 1.60
   Z = runif(Y[i], min_val, max_val)   
   }
   else
   {
   if(X[i] == 'A13')
   {
   min_val = 1.60
   max_val = 1.99
   Z = runif(Y[i], min_val, max_val)   
   }
   }
   }
   }
 
# End of Code
 
## _
 
PROBLEM
 
I need to get 61 random numbers which is total of all the numbers (1st 12 fo
A, 3 random numbers for B, 13 for C, 5 again fo A and so on). The result
whcih I got is
 
 Z
[1] 1.740443 1.761758 1.797222
 
which is pertaining to the last name C where 3 random numbers are generated
i.e. Z instaed of getting added, is overwritten.
 
Please help me to rectify my code so that in the end I will get 61 random
numbers as desired i.e. 12 for A in the range (1.05 - 1.30), 3 for B in the
range (1.30 - 1.60), 13 for C in the range (1.60-1.99), again 5 for A in the
range (1.05 - 1.30).
 
Thanking in advance. I also sincerely apologize for writing such a long
mail, as I wanted to be clear as possible in my communication.
 
Regards
 
Maithili
 
 


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[R] Random number generation for Generalized Logistic distribution

[Maithili Shiva]

Dear R helpers

How to generate random numbers for 

(a)  Generalized logistic distribution

(b)  Generalized normal distribution

(c)  Pearson Type III distribution

(d) Kappa

Thanks in advance


Maithili

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Re: [R] Random number generation for Generalized Logistic distribution

[William Asquith]

See the lmom package by J.R.M Hosking
or
lmomco package by W.H.Asquith

-wha

On Feb 24, 2009, at 5:46 AM, Maithili Shiva wrote:


Dear R helpers

How to generate random numbers for

(a)  Generalized logistic distribution

(b)  Generalized normal distribution

(c)  Pearson Type III distribution

(d) Kappa

Thanks in advance


Maithili

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[R] Random Number Generation using (Generalized) Extreme Value distribution and Pareto distribution

[Maithili Shiva]

Hi R helpers,


Is there any function in R, which generates random numbers in case of 

(1) Generalized Extreme Value distribution and 

(2) Generalized PAreto distribution  for the respective given set of parameters?


Regards


Maithili

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Re: [R] Random Number Generation using (Generalized) Extreme Value distribution and Pareto distribution

[Jorge Ivan Velez]

Dear Maithili,
For (1) see [1] and for (2) see page 24 in [2].

HTH,

Jorge

[1] http://www.stat.ucl.ac.be/ISdidactique/Rhelp/library/evd/html/gev.html
[2] http://cran.r-project.org/web/packages/fExtremes/fExtremes.pdf



On Thu, Dec 18, 2008 at 3:17 AM, Maithili Shiva maithili_sh...@yahoo.comwrote:

 Hi R helpers,


 Is there any function in R, which generates random numbers in case of

 (1) Generalized Extreme Value distribution and

 (2) Generalized PAreto distribution  for the respective given set of
 parameters?


 Regards


 Maithili

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[R] R random number generation

[hiphop]

i have to generate random numbers from length 2 to 30 and length two should
have the numbers 1,2 and length 3 should have the numbers 1,2,3 so on and so
forth till size 30.i should get an sequence like 221 or 112 till
both the values appear and for 3 it should be 123 or 3331112.i should
get similar output for all sizes which means i should get 30 sequences.but
am getting only one sequence .please help.
this is my code

y=0;
for (i in 1:3)
{
while(y!=i)
{
y=sample(1:3,replace=TRUE);
}
}

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Re: [R] R random number generation

[Ted Harding]

On 23-Oct-08 19:58:12, hiphop wrote:
 
 i have to generate random numbers from length 2 to 30 and
 length two should have the numbers 1,2 and length 3 should
 have the numbers 1,2,3 so on and so forth till size 30.
 i should get an sequence like 221 or 112 till both
 the values appear and for 3 it should be 123 or 3331112.
 i should get similar output for all sizes which means i should
 get 30 sequences.but am getting only one sequence.
 please help. this is my code
 
 y=0;
 for (i in 1:3)
 {
 while(y!=i)
 {
 y=sample(1:3,replace=TRUE);
 }
 }

If I understand you correctly, the following should do what
you are looking for (i.e. sample repeatedly from (1:k) until
you first have all of 1:k in the sample, repetitions being
allowed):

  mksample - function(k){
All - (1:k) ; Left - rep(TRUE,k) ; Done - FALSE
Result - NULL
while(! Done){
  j - sample(All,1)
  Result - c(Result, j); Left[j] - FALSE
  Done - (sum(Left)==0)
}
Result
  }

Example:
  mksample(5)
# [1] 1 4 4 5 2 1 1 3

I'm not clear about why, in your illustrations (such as
3331112) you presented it as a sequence of runs (333,
111,2) -- maybe this is not relevant to your query.

Hoping this helps,
Ted.


E-Mail: (Ted Harding) [EMAIL PROTECTED]
Fax-to-email: +44 (0)870 094 0861
Date: 23-Oct-08   Time: 21:51:04
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Re: [R] R random number generation

[hiphop]

hi

thanks for the reply
actually am supposed to generate random numbers in oncreasing size.
so when i say 1,2 i should get something like 1 or 221 or 1112 ...i
should get both the values 1 and 2 in a random order but it should stop when
both the values occur atleast once in the sequence.so after 1,2 it should be
1,2,3 and the sequence generated should have 1,2,3 atleast once.then it
should generate a random sequence of numbers 1,2,3,4 ...it should go on till
it generates 1,230.hope am clear now.



hiphop wrote:
 
 i have to generate random numbers from length 2 to 30 and length two
 should have the numbers 1,2 and length 3 should have the numbers 1,2,3 so
 on and so forth till size 30.i should get an sequence like 221 or
 112 till both the values appear and for 3 it should be 123 or
 3331112.i should get similar output for all sizes which means i should get
 30 sequences.but am getting only one sequence .please help.
 this is my code
 
 y=0;
 for (i in 1:3)
 {
 while(y!=i)
 {
 y=sample(1:3,replace=TRUE);
 }
 }
 
 

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Re: [R] R random number generation

[markleeds]

below i think semi does what you want but it's never going to repeat a 
value because it's sampling without replacement ? in that sense,
it's not as general as what you asked for. if you need the repeating 
thing, then i'm not sure how to do that. hopefully someone else does.


lapply(1:30, function(.index) {
   sample(1:.index,replace=FALSE,size=.index)
})





On Thu, Oct 23, 2008 at  8:53 PM, hiphop wrote:


hi

thanks for the reply
actually am supposed to generate random numbers in oncreasing size.
so when i say 1,2 i should get something like 1 or 221 or 1112 
...i
should get both the values 1 and 2 in a random order but it should 
stop when
both the values occur atleast once in the sequence.so after 1,2 it 
should be
1,2,3 and the sequence generated should have 1,2,3 atleast once.then 
it
should generate a random sequence of numbers 1,2,3,4 ...it should go 
on till

it generates 1,230.hope am clear now.



hiphop wrote:


i have to generate random numbers from length 2 to 30 and length two
should have the numbers 1,2 and length 3 should have the numbers 
1,2,3 so

on and so forth till size 30.i should get an sequence like 221 or
112 till both the values appear and for 3 it should be 123 or
3331112.i should get similar output for all sizes which means i 
should get

30 sequences.but am getting only one sequence .please help.
this is my code

y=0;
for (i in 1:3)
{
while(y!=i)
{
y=sample(1:3,replace=TRUE);
}
}




--
View this message in context: 
http://www.nabble.com/R-random-number-generation-tp20138441p20142412.html

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Re: [R] Random number generation

[Duncan Murdoch]

Please don't cross-post.  I've replied in R-devel.

On 8/5/2008 8:47 AM, subramanian R wrote:

Hi All,
   I have a few queries regarding Random Number generation in R.
   according to the help(Random.User) i defined my own functions for
user_unif_rand and user_norm_rand (uniform and normal distribution)

   But what i figured out was even when i call rexp,rpois,rgeom and
other distributions they were routed via user_unif_rand.
1.  Does this mean that for all types of distribution it generates an
Uniform distribution and transforms to the requested type?

Also   surprisingly even rnorm which i hoped to route via user_norm_rand
was calling user_unif_rand...



rnorm(1)

inside user_unif_rand//printf and
inside user_unif_rand
[1] 0.5973648


Please help me out understanding this...

2. Our goal is to link with an vectorized Random number generator library
for our multi-core architecture.
So is it enough if we define user_unif_rand function alone and will it
take care of all distributions?


Thanks in Anticipation,
R. Subramanian

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[R] Random number generation

[Max]

Hi Everyone,

I did a quick search of the list and it looks like this may not have 
been asked before... I'm trying to generate a matrix of random numbers 
between 0 and 1, with 6 columns, 1 rows. About all I know is that 
runif(1) gives me the random number I'm looking for.


Any help would be great!

thanks,

-Max

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Re: [R] Random number generation

[Marc Schwartz]

on 07/31/2008 12:24 PM Max wrote:

Hi Everyone,

I did a quick search of the list and it looks like this may not have 
been asked before... I'm trying to generate a matrix of random numbers 
between 0 and 1, with 6 columns, 1 rows. About all I know is that 
runif(1) gives me the random number I'm looking for.


Any help would be great!

thanks,


MAT - matrix(runif(1 * 6), 1, 6)

 str(MAT)
 num [1:1, 1:6] 0.753 0.600 0.806 0.713 0.796 ...

 head(MAT, 10)
[,1]  [,2]   [,3]   [,4]   [,5]   [,6]
 [1,] 0.75343430 0.4993896 0.68554749 0.01924549 0.90579982 0.99606191
 [2,] 0.59957219 0.4075650 0.57851744 0.97208426 0.32137505 0.02089689
 [3,] 0.80567935 0.5746030 0.16520072 0.92615138 0.01628994 0.90075333
 [4,] 0.71270574 0.3252210 0.53765089 0.58930899 0.03053356 0.23282879
 [5,] 0.79603691 0.5591622 0.97308348 0.52744458 0.76403708 0.22268021
 [6,] 0.49624259 0.5106604 0.06687444 0.48659150 0.29803454 0.91760758
 [7,] 0.32921909 0.7784539 0.20468873 0.86730697 0.42581735 0.59344279
 [8,] 0.93646405 0.4819996 0.79033546 0.68441917 0.28566573 0.97244395
 [9,] 0.02964297 0.5489500 0.64355067 0.87131530 0.58505804 0.06972828
[10,] 0.55956266 0.8376349 0.11850374 0.37687892 0.71220844 0.97784727



The first argument to runif() is how many random deviates you want to 
generate. If you need to be able to reproduce the exact sequence again 
in the future, see ?set.seed.


HTH,

Marc Schwartz

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Re: [R] Random number generation

[Max]

Marc,

this is very handy. My next question is, do you know a quick and easy 
way to transfer all of the output to a txt file? (or .xls)?


Thanks,

-Max


Marc Schwartz explained on 07/31/2008 :

on 07/31/2008 12:24 PM Max wrote:

Hi Everyone,

I did a quick search of the list and it looks like this may not have been 
asked before... I'm trying to generate a matrix of random numbers between 0 
and 1, with 6 columns, 1 rows. About all I know is that runif(1) gives 
me the random number I'm looking for.


Any help would be great!

thanks,


MAT - matrix(runif(1 * 6), 1, 6)

  str(MAT)
  num [1:1, 1:6] 0.753 0.600 0.806 0.713 0.796 ...

  head(MAT, 10)
 [,1]  [,2]   [,3]   [,4]   [,5]   [,6]
  [1,] 0.75343430 0.4993896 0.68554749 0.01924549 0.90579982 0.99606191
  [2,] 0.59957219 0.4075650 0.57851744 0.97208426 0.32137505 0.02089689
  [3,] 0.80567935 0.5746030 0.16520072 0.92615138 0.01628994 0.90075333
  [4,] 0.71270574 0.3252210 0.53765089 0.58930899 0.03053356 0.23282879
  [5,] 0.79603691 0.5591622 0.97308348 0.52744458 0.76403708 0.22268021
  [6,] 0.49624259 0.5106604 0.06687444 0.48659150 0.29803454 0.91760758
  [7,] 0.32921909 0.7784539 0.20468873 0.86730697 0.42581735 0.59344279
  [8,] 0.93646405 0.4819996 0.79033546 0.68441917 0.28566573 0.97244395
  [9,] 0.02964297 0.5489500 0.64355067 0.87131530 0.58505804 0.06972828
[10,] 0.55956266 0.8376349 0.11850374 0.37687892 0.71220844 0.97784727



The first argument to runif() is how many random deviates you want to 
generate. If you need to be able to reproduce the exact sequence again in the 
future, see ?set.seed.


HTH,

Marc Schwartz

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Re: [R] Random number generation

[Jorge Ivan Velez]

Hi Max,

See ?write.table.  Perhaps:

MAT - matrix(runif(1 * 6), 1, 6)

# TXT format
write.table(MAT,
C:/yourmatrix.txt,col.names=FALSE,row.names=FALSE,quote=FALSE)

# XLS format
write.table(MAT,
C:/yourmatrix.xls,col.names=FALSE,row.names=FALSE,quote=FALSE,sep=\t)

HTH,

Jorge



On Thu, Jul 31, 2008 at 1:53 PM, Max [EMAIL PROTECTED] wrote:

 Marc,

 this is very handy. My next question is, do you know a quick and easy way
 to transfer all of the output to a txt file? (or .xls)?

 Thanks,

 -Max


 Marc Schwartz explained on 07/31/2008 :

  on 07/31/2008 12:24 PM Max wrote:

 Hi Everyone,

 I did a quick search of the list and it looks like this may not have been
 asked before... I'm trying to generate a matrix of random numbers between 0
 and 1, with 6 columns, 1 rows. About all I know is that runif(1) gives
 me the random number I'm looking for.

 Any help would be great!

 thanks,


 MAT - matrix(runif(1 * 6), 1, 6)

   str(MAT)
  num [1:1, 1:6] 0.753 0.600 0.806 0.713 0.796 ...

   head(MAT, 10)
 [,1]  [,2]   [,3]   [,4]   [,5]   [,6]
  [1,] 0.75343430 0.4993896 0.68554749 0.01924549 0.90579982 0.99606191
  [2,] 0.59957219 0.4075650 0.57851744 0.97208426 0.32137505 0.02089689
  [3,] 0.80567935 0.5746030 0.16520072 0.92615138 0.01628994 0.90075333
  [4,] 0.71270574 0.3252210 0.53765089 0.58930899 0.03053356 0.23282879
  [5,] 0.79603691 0.5591622 0.97308348 0.52744458 0.76403708 0.22268021
  [6,] 0.49624259 0.5106604 0.06687444 0.48659150 0.29803454 0.91760758
  [7,] 0.32921909 0.7784539 0.20468873 0.86730697 0.42581735 0.59344279
  [8,] 0.93646405 0.4819996 0.79033546 0.68441917 0.28566573 0.97244395
  [9,] 0.02964297 0.5489500 0.64355067 0.87131530 0.58505804 0.06972828
 [10,] 0.55956266 0.8376349 0.11850374 0.37687892 0.71220844 0.97784727



 The first argument to runif() is how many random deviates you want to
 generate. If you need to be able to reproduce the exact sequence again in
 the future, see ?set.seed.

 HTH,

 Marc Schwartz

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
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 R-help@r-project.org mailing list
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Re: [R] Random number generation

[Patrizio Frederic]

?write.table

could help

PF

2008/7/31 Max [EMAIL PROTECTED]:
 Marc,

 this is very handy. My next question is, do you know a quick and easy way to
 transfer all of the output to a txt file? (or .xls)?

 Thanks,

 -Max


 Marc Schwartz explained on 07/31/2008 :

 on 07/31/2008 12:24 PM Max wrote:

 Hi Everyone,

 I did a quick search of the list and it looks like this may not have been
 asked before... I'm trying to generate a matrix of random numbers between 0
 and 1, with 6 columns, 1 rows. About all I know is that runif(1) gives
 me the random number I'm looking for.

 Any help would be great!

 thanks,

 MAT - matrix(runif(1 * 6), 1, 6)

   str(MAT)
  num [1:1, 1:6] 0.753 0.600 0.806 0.713 0.796 ...

   head(MAT, 10)
 [,1]  [,2]   [,3]   [,4]   [,5]   [,6]
  [1,] 0.75343430 0.4993896 0.68554749 0.01924549 0.90579982 0.99606191
  [2,] 0.59957219 0.4075650 0.57851744 0.97208426 0.32137505 0.02089689
  [3,] 0.80567935 0.5746030 0.16520072 0.92615138 0.01628994 0.90075333
  [4,] 0.71270574 0.3252210 0.53765089 0.58930899 0.03053356 0.23282879
  [5,] 0.79603691 0.5591622 0.97308348 0.52744458 0.76403708 0.22268021
  [6,] 0.49624259 0.5106604 0.06687444 0.48659150 0.29803454 0.91760758
  [7,] 0.32921909 0.7784539 0.20468873 0.86730697 0.42581735 0.59344279
  [8,] 0.93646405 0.4819996 0.79033546 0.68441917 0.28566573 0.97244395
  [9,] 0.02964297 0.5489500 0.64355067 0.87131530 0.58505804 0.06972828
 [10,] 0.55956266 0.8376349 0.11850374 0.37687892 0.71220844 0.97784727



 The first argument to runif() is how many random deviates you want to
 generate. If you need to be able to reproduce the exact sequence again in
 the future, see ?set.seed.

 HTH,

 Marc Schwartz

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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Re: [R] Random number generation

[David Barron]

m - runif(6)
mm - matrix(m, ncol=6)

HTH

Dave

On Thu, Jul 31, 2008 at 6:24 PM, Max [EMAIL PROTECTED] wrote:

 Hi Everyone,

 I did a quick search of the list and it looks like this may not have been
 asked before... I'm trying to generate a matrix of random numbers between 0
 and 1, with 6 columns, 1 rows. About all I know is that runif(1) gives
 me the random number I'm looking for.

 Any help would be great!

 thanks,

 -Max

 __
 R-help@r-project.org mailing list
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide
 http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.




-- 
David Barron
Said Business School
Park End Street
Oxford OX1 1HP
01865 288906

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Re: [R] Random number generation

[Max]

This is perfect, thanks! :)

Jorge Ivan Velez pretended :

Hi Max,

See ?write.table.  Perhaps:

MAT - matrix(runif(1 * 6), 1, 6)

# TXT format
write.table(MAT,
C:/yourmatrix.txt,col.names=FALSE,row.names=FALSE,quote=FALSE)

# XLS format
write.table(MAT,
C:/yourmatrix.xls,col.names=FALSE,row.names=FALSE,quote=FALSE,sep=\t)

HTH,

Jorge



On Thu, Jul 31, 2008 at 1:53 PM, Max [EMAIL PROTECTED] wrote:


Marc,

this is very handy. My next question is, do you know a quick and easy way
to transfer all of the output to a txt file? (or .xls)?

Thanks,

-Max


Marc Schwartz explained on 07/31/2008 :

 on 07/31/2008 12:24 PM Max wrote:



Hi Everyone,

I did a quick search of the list and it looks like this may not have been
asked before... I'm trying to generate a matrix of random numbers between 
0 and 1, with 6 columns, 1 rows. About all I know is that runif(1) 
gives me the random number I'm looking for.


Any help would be great!

thanks,



MAT - matrix(runif(1 * 6), 1, 6)

  str(MAT)
 num [1:1, 1:6] 0.753 0.600 0.806 0.713 0.796 ...

  head(MAT, 10)
[,1]  [,2]   [,3]   [,4]   [,5]   [,6]
 [1,] 0.75343430 0.4993896 0.68554749 0.01924549 0.90579982 0.99606191
 [2,] 0.59957219 0.4075650 0.57851744 0.97208426 0.32137505 0.02089689
 [3,] 0.80567935 0.5746030 0.16520072 0.92615138 0.01628994 0.90075333
 [4,] 0.71270574 0.3252210 0.53765089 0.58930899 0.03053356 0.23282879
 [5,] 0.79603691 0.5591622 0.97308348 0.52744458 0.76403708 0.22268021
 [6,] 0.49624259 0.5106604 0.06687444 0.48659150 0.29803454 0.91760758
 [7,] 0.32921909 0.7784539 0.20468873 0.86730697 0.42581735 0.59344279
 [8,] 0.93646405 0.4819996 0.79033546 0.68441917 0.28566573 0.97244395
 [9,] 0.02964297 0.5489500 0.64355067 0.87131530 0.58505804 0.06972828
[10,] 0.55956266 0.8376349 0.11850374 0.37687892 0.71220844 0.97784727



The first argument to runif() is how many random deviates you want to
generate. If you need to be able to reproduce the exact sequence again in
the future, see ?set.seed.

HTH,

Marc Schwartz

__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.



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Re: [R] Random number generation

[Jim Lemon]

On Behalf Of Esmail Bonakdarian wrote:
 ...
 What I read doesn't seem to be incorrect however (it may even
 have been an archived message here), the *language* itself
 does not seem to support block *comments*. Using conditional
 constructs, or an IDE/editor to achieve similar results is a
 work around - but not the same. I don't mean to nitpick, but
 as a computer scientist I see this as different :-)

For those using NEdit, the R block comment macro:

replace_in_selection(^,#,regex)

and the corresponding R block uncomment macro:

replace_in_selection(^#,,regex)

are both trivial. Just highlight the block and detonate the macro.

Jim

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Re: [R] Random number generation

[Esmail Bonakdarian]

Greg Snow wrote:

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Esmail Bonakdarian
Sent: Sunday, May 11, 2008 7:25 AM
To: Prof Brian Ripley
Cc: [EMAIL PROTECTED]
Subject: Re: [R] Random number generation


[snip]


What I read doesn't seem to be incorrect however (it may even
have been an archived message here), the *language* itself
does not seem to support block *comments*. Using conditional
constructs, or an IDE/editor to achieve similar results is a
work around - but not the same. I don't mean to nitpick, but
as a computer scientist I see this as different :-)


I am not a computer scientist, so correct me if I am wrong, but from what I remember (and a quick glance at my copy of Kernighan Ritchie), the C *language* itself does not support block *comments*, rather the preproccessor 


Hi there,

Yes, while that may be true, many other languages that don't use an
explicit pre-processor mechanism (though internally will go
through a similar process) do support block comments. It's a
moot point anyway, since when you compile a C program the preprocessor
also runs (just like the linker etc) unless you specifically ask for
something differently via command line switches. As far as the
programmer is concerned the semantics are those of a language
that provides block comments with the simple use of /* */ , and
not dependent on if-statements or editor/IDE tricks.

Since R is optimized for interactive use rather than compilation, running everything through a preproccessor is not really an option.  However as an additional work around 


My use then may be not typical since I am trying to write scripts in R
and only use R directly to try out functions/language constructs.

you could always run your R scripts through the C preproccessor and 

 have it strip the block comments for you.

Too much work, call me old school, but I like the computer do work for me,
rather than the other way around :-)


Given the complexity of implementing block commenting (even deciding on the 
syntax) and the ease of current work arounds, the cost benefit ratio probably 
puts this very near the bottom of the priority list.


I couldn't possibly offer an opinion on that .. I'll happily defer to you
and the other experts here for this.

Cheers,
Esmail

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Re: [R] Random number generation

[Karl Ove Hufthammer]

Esmail Bonakdarian:

 you could always run your R scripts through the C preproccessor and
  have it strip the block comments for you.
 
 Too much work, call me old school, but I like the computer do work for me,
 rather than the other way around

Most editors (and every editor worth using) supports block-commenting via a
keyboard shortcut. For instance, in KDE-based editors, such as Kwrite, Kate
and RKward (the latter is a KDE-based GUI for R), you can just select the
lines you want to comment and press 'Ctrl + D' to comment them, or 'Shift +
Ctrl + D' to uncomment them.

-- 
Karl Ove Hufthammer

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Re: [R] Random number generation

[Greg Snow]

 -Original Message-
 From: Esmail Bonakdarian [mailto:[EMAIL PROTECTED]
 Sent: Tuesday, May 13, 2008 8:13 AM
 To: Greg Snow
 Cc: Prof Brian Ripley; [EMAIL PROTECTED]
 Subject: Re: [R] Random number generation

 Greg Snow wrote:
  -Original Message-
[snip]

  you could always run your R scripts through the C preproccessor and
   have it strip the block comments for you.

 Too much work, call me old school, but I like the computer do
 work for me, rather than the other way around :-)

So, have the computer do the work.  Here is a simple function that tells the 
computer to do the work:

cppsource - function(file) {
tmp - paste(tempfile(), '.R', sep='')
system(paste('cpp',file,tmp))
source(tmp)
unlink(tmp)
}

Now, instead of doing source('myfile.R') do cppsource('myfile.R') and it will 
automatically do the preproccing to remove the c-style comments (assuming that 
cpp is on your path, etc.).  If typing the extra 3 characters is too much work, 
then just name it something else.

Or if you just want to strip the comments in R and don't want to use the c 
preprocessor then the function:

cssource - function(file) {
tmp - readLines(file)
tmp2 - paste(tmp, collapse='\n')
tmp3 - gsub('(?s)/\\*.*?\\*/','',tmp2,perl=TRUE)
source(textConnection(tmp3))
}

Will do that (it will not deal with nested comments or some other special 
cases, but both the above functions worked for my quick test case).




  Given the complexity of implementing block commenting (even
 deciding on the syntax) and the ease of current work arounds,
 the cost benefit ratio probably puts this very near the
 bottom of the priority list.

 I couldn't possibly offer an opinion on that .. I'll happily
 defer to you and the other experts here for this.

I am not really an expert on this.  I just remember being bitten when writing C 
and trying to comment out a section of code that already had a comment in it.  
I would rather have the R core team spending their time on their current 
priorities than even get involved in a discussion of whether block comments 
should be able to be nested or not.

You now have at least 4 possible work arounds, hopefully one of them is 
satifactory,


--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111

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Re: [R] Random number generation

[Duncan Murdoch]

On 5/13/2008 1:38 PM, Greg Snow wrote:

-Original Message-
From: Esmail Bonakdarian [mailto:[EMAIL PROTECTED]
Sent: Tuesday, May 13, 2008 8:13 AM
To: Greg Snow
Cc: Prof Brian Ripley; [EMAIL PROTECTED]
Subject: Re: [R] Random number generation

Greg Snow wrote:
 -Original Message-

[snip]


 you could always run your R scripts through the C preproccessor and
  have it strip the block comments for you.

Too much work, call me old school, but I like the computer do
work for me, rather than the other way around :-)


So, have the computer do the work.  Here is a simple function that tells the 
computer to do the work:

cppsource - function(file) {
tmp - paste(tempfile(), '.R', sep='')
system(paste('cpp',file,tmp))
source(tmp)
unlink(tmp)
}

Now, instead of doing source('myfile.R') do cppsource('myfile.R') and it will 
automatically do the preproccing to remove the c-style comments (assuming that 
cpp is on your path, etc.).  If typing the extra 3 characters is too much work, 
then just name it something else.

Or if you just want to strip the comments in R and don't want to use the c 
preprocessor then the function:

cssource - function(file) {
tmp - readLines(file)
tmp2 - paste(tmp, collapse='\n')
tmp3 - gsub('(?s)/\\*.*?\\*/','',tmp2,perl=TRUE)
source(textConnection(tmp3))
}

Will do that (it will not deal with nested comments or some other special 
cases, but both the above functions worked for my quick test case).


One problem with this idea is that it makes the very helpful syntax 
error messages from source() less useful:


 cppsource('test.R')
Error in source(tmp) :
  c:\temp\Rtmpmyoc5a\file678418be.R: unexpected symbol at
8:
9: if (y  1:2 cat

Duncan Murdoch



 Given the complexity of implementing block commenting (even
deciding on the syntax) and the ease of current work arounds,
the cost benefit ratio probably puts this very near the
bottom of the priority list.

I couldn't possibly offer an opinion on that .. I'll happily
defer to you and the other experts here for this.


I am not really an expert on this.  I just remember being bitten when writing C 
and trying to comment out a section of code that already had a comment in it.  
I would rather have the R core team spending their time on their current 
priorities than even get involved in a discussion of whether block comments 
should be able to be nested or not.

You now have at least 4 possible work arounds, hopefully one of them is 
satifactory,


--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111

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Re: [R] Random number generation

[Greg Snow]

 -Original Message-
 From: [EMAIL PROTECTED]
 [mailto:[EMAIL PROTECTED] On Behalf Of Esmail Bonakdarian
 Sent: Sunday, May 11, 2008 7:25 AM
 To: Prof Brian Ripley
 Cc: [EMAIL PROTECTED]
 Subject: Re: [R] Random number generation

[snip]

 What I read doesn't seem to be incorrect however (it may even
 have been an archived message here), the *language* itself
 does not seem to support block *comments*. Using conditional
 constructs, or an IDE/editor to achieve similar results is a
 work around - but not the same. I don't mean to nitpick, but
 as a computer scientist I see this as different :-)

I am not a computer scientist, so correct me if I am wrong, but from what I 
remember (and a quick glance at my copy of Kernighan Ritchie), the C *language* 
itself does not support block *comments*, rather the preproccessor replaces the 
comments with a single space and the compilor does not even see them.

Since R is optimized for interactive use rather than compilation, running 
everything through a preproccessor is not really an option.  However as an 
additional work around you could always run your R scripts through the C 
preproccessor and have it strip the block comments for you.

Given the complexity of implementing block commenting (even deciding on the 
syntax) and the ease of current work arounds, the cost benefit ratio probably 
puts this very near the bottom of the priority list.


--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
(801) 408-8111

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Re: [R] Random number generation

[Stephan Kolassa]

Dennis,

I assume that there is a set.seed() somewhere in your script, possibly 
in something you source()d (hopefully not in anything library()d).


Have you tried successively removing/commenting parts of the script 
before the sample() command until the problem goes away? That way you 
should be able to pinpoint the offending script command.


Good luck,
Stephan


Dennis Fisher schrieb:

Colleagues,

I have encountered behavior of random number generation that eludes me.

I generate a random integer in a particular range using the following  
code:

sample(1000:, size=1)

This code exists within a script that starts with the command:
remove(list=ls())

Each time that I run the script, it yields the same random number: 	 
6420.


I thought that the problem might result from deleting the random  
seed.  However, list=ls() does not include .RandomSeed.


To my surprise, I can't replicate the problem with a 2-line script:
remove(list-ls())
sample(1000:, size=1)

Also, the same problem occurs if I use runif instead of sample.

Thoughts?

Dennis

Dennis Fisher MD
P  (The P Less Than Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com


[[alternative HTML version deleted]]

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Re: [R] Random number generation

[Esmail Bonakdarian]

Stephan Kolassa wrote:


Have you tried successively removing/commenting parts of the script 
before the sample() command until the problem goes away? That way you 
should be able to pinpoint the offending script command.


Hi,

This brings up a question I have .. is there a way to do *block* comments
with scripts? A la /* ... */ like it's done in Java or C/C++? Ie comment
more than just one line at a time.

From what I have read this is not possible in R (at least not easily), but
I am eager for someone to contradict me :-)

Thanks,
Esmail

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Re: [R] Random number generation

[Prof Brian Ripley]

On Sun, 11 May 2008, Esmail Bonakdarian wrote:


Stephan Kolassa wrote:


Have you tried successively removing/commenting parts of the script before 
the sample() command until the problem goes away? That way you should be 
able to pinpoint the offending script command.


Hi,

This brings up a question I have .. is there a way to do *block* comments
with scripts? A la /* ... */ like it's done in Java or C/C++? Ie comment
more than just one line at a time.

From what I have read this is not possible in R (at least not easily), but
I am eager for someone to contradict me :-)


if(FALSE) {
...
}

Any good editor can do block commenting, e.g. ESS.

You didn't tell us what you read, but I have never seen this in a 
reputable source.



Thanks,
Esmail


--
Brian D. Ripley,  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel:  +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UKFax:  +44 1865 272595

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Re: [R] Random number generation

[Esmail Bonakdarian]

Hello there,

Prof Brian Ripley wrote:

On Sun, 11 May 2008, Esmail Bonakdarian wrote:


Stephan Kolassa wrote:


Have you tried successively removing/commenting parts of the script 
before the sample() command until the problem goes away? That way you 
should be able to pinpoint the offending script command.


Hi,

This brings up a question I have .. is there a way to do *block* comments
with scripts? A la /* ... */ like it's done in Java or C/C++? Ie comment
more than just one line at a time.

From what I have read this is not possible in R (at least not easily), 
but

I am eager for someone to contradict me :-)


if(FALSE) {
...
}

Any good editor can do block commenting, e.g. ESS.

You didn't tell us what you read, but I have never seen this in a 
reputable source.


I don't remember the source as I was reading widely all over the place
trying to get up to speed with R in a hurry  (having found this group
was one of the best sources).

What I read doesn't seem to be incorrect however (it may even have been an
archived message here), the *language* itself does not seem to support block
*comments*. Using conditional constructs, or an IDE/editor to achieve similar
results is a work around - but not the same. I don't mean to nitpick, but
as a computer scientist I see this as different :-)

I'll have to look at ESS though.

Thanks,
Esmail

ps: Ah, I seem Meta-; works as a toggle in emacs/ESS .. thanks for encouraging
me to look at that some more.

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[R] Random number generation

[Dennis Fisher]

Colleagues,

I have encountered behavior of random number generation that eludes me.

I generate a random integer in a particular range using the following  
code:
sample(1000:, size=1)

This code exists within a script that starts with the command:
remove(list=ls())

Each time that I run the script, it yields the same random number:   
6420.

I thought that the problem might result from deleting the random  
seed.  However, list=ls() does not include .RandomSeed.

To my surprise, I can't replicate the problem with a 2-line script:
remove(list-ls())
sample(1000:, size=1)

Also, the same problem occurs if I use runif instead of sample.

Thoughts?

Dennis

Dennis Fisher MD
P  (The P Less Than Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com


[[alternative HTML version deleted]]

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