random numbers

[Arthur Kramer]

I would like to generate two random distributions of 25 cases, say with means of 22 and 27 and standard deviations of 5 and 6.  Can this be done with SPSS? If so, how?

 

Thanks for any help you can provide.

 

Arthur Kramer

 

[Art Kendall]

Open a new instance of SPSS.  Copy and paste the example syntax below into a syntax window. Run it. You can change the N, means, and SDs.


* prepare two distributions as if for t-test.
set seed 20101802.
input program.
loop #i = 1 to 25.
compute group =1.
compute x = rv.normal(22,5).
end case.
end loop.
loop #i = 1 to 25.
compute group =2.
compute x = rv.normal(27,6).
end case.
end loop.
end file.
end input program.
T-TEST GROUPS=group(1 2) /variables = x.

Art Kendall
Social Research Consultants

On 2/18/2010 1:59 PM, Arthur Kramer wrote:

I would like to generate two random distributions of 25 cases, say with means of 22 and 27 and standard deviations of 5 and 6.  Can this be done with SPSS? If so, how?

 

Thanks for any help you can provide.

 

Arthur Kramer

 

===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD

[Arthur Kramer]

Perfect. Thanks.

 

Arthur Kramer

 

 

---

From: Art Kendall [mailto:[hidden email]]
Sent: Thursday, February 18, 2010 2:26 PM
To: Arthur Kramer
Cc: [hidden email]
Subject: Re: [SPSSX-L] random numbers

 

Open a new instance of SPSS.  Copy and paste the example syntax below into a syntax window. Run it. You can change the N, means, and SDs.


* prepare two distributions as if for t-test.
set seed 20101802.
input program.
loop #i = 1 to 25.
compute group =1.
compute x = rv.normal(22,5).
end case.
end loop.
loop #i = 1 to 25.
compute group =2.
compute x = rv.normal(27,6).
end case.
end loop.
end file.
end input program.
T-TEST GROUPS=group(1 2) /variables = x.

Art Kendall
Social Research Consultants

On 2/18/2010 1:59 PM, Arthur Kramer wrote:

I would like to generate two random distributions of 25 cases, say with means of 22 and 27 and standard deviations of 5 and 6.  Can this be done with SPSS? If so, how?

 

Thanks for any help you can provide.

 

Arthur Kramer

 

[Bruce Weaver]

Arthur Kramer wrote

I would like to generate two random distributions of 25 cases, say with
means of 22 and 27 and standard deviations of 5 and 6.  Can this be done
with SPSS? If so, how?



Thanks for any help you can provide.



Arthur Kramer

Hi Art.  You didn't say what kind of distribution you want to sample from, so I will assume it is normal.

* If you want 2 variables side by side .

new file.
dataset close all.
input program.
loop #i = 1 to 25.
 compute case = $casenum.
 compute x1 = rv.normal(22,5). /* Mean=22, SD=5 .
 compute x2 = rv.normal(27,6). /* Mean=27, SD=6 .
end case.
end loop.
end file.
end input program.
exe.

means x1 x2.

* If you want one X-variable with a Group variable.

new file.
dataset close all.
input program.
loop #i = 1 to 50.
 compute case = $casenum.
 do if case LE 25.
  compute group = 1.
  compute x = rv.normal(22,5).
 else.
  compute group = 2.
  compute x = rv.normal(27,6).
 end if.
end case.
end loop.
end file.
end input program.
exe.

means x by group.

There are RV functions for a bunch of other distributions too, if you don't want the normal.  Search for "Random variable functions" under Help - Topics - Index.

HTH.

Cheers,
Bruce

[Arthur Kramer]

Thanks, that works great also. An hour ago I didn't have anything, now I
have two.  Life is good!

Arthur Kramer


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of
Bruce Weaver
Sent: Thursday, February 18, 2010 2:30 PM
To: [hidden email]
Subject: Re: random numbers

Arthur Kramer wrote:

>
> I would like to generate two random distributions of 25 cases, say with
> means of 22 and 27 and standard deviations of 5 and 6.  Can this be done
> with SPSS? If so, how?
>
>
>
> Thanks for any help you can provide.
>
>
>
> Arthur Kramer
>
>
>

Hi Art.  You didn't say what kind of distribution you want to sample from,
so I will assume it is normal.

* If you want 2 variables side by side .

new file.
dataset close all.
input program.
loop #i = 1 to 25.
 compute case = $casenum.
 compute x1 = rv.normal(22,5). /* Mean=22, SD=5 .
 compute x2 = rv.normal(27,6). /* Mean=27, SD=6 .
end case.
end loop.
end file.
end input program.
exe.

means x1 x2.

* If you want one X-variable with a Group variable.

new file.
dataset close all.
input program.
loop #i = 1 to 50.
 compute case = $casenum.
 do if case LE 25.
  compute group = 1.
  compute x = rv.normal(22,5).
 else.
  compute group = 2.
  compute x = rv.normal(27,6).
 end if.
end case.
end loop.
end file.
end input program.
exe.

means x by group.

There are RV functions for a bunch of other distributions too, if you don't
want the normal.  Search for "Random variable functions" under Help - Topics
- Index.

HTH.

Cheers,
Bruce


-----
--
Bruce Weaver
[hidden email]
http://sites.google.com/a/lakeheadu.ca/bweaver/
"When all else fails, RTFM."

NOTE:  My Hotmail account is not monitored regularly.
To send me an e-mail, please use the address shown above.
--
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=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD