Random Numbers in Matrix Mode

[bdates]

Is it possible to generate uniform random numbers in a specific range in matrix mode?  For example, if I want to create a vector (i=100, j=1) of random numbers between 3 and 10, there doesn't seem to be a solution.  If n=100 and I use compute x=trunc(uniform(100,1)*n), I get numbers between 1 and 10.  If I use x=trunc(uniform(100,1)*n+2), I get numbers between 3 and 12.  So in one case I get the desired top of the range, and in the other I get the desired bottom of the range.  Any assistance is appreciated.  Thanks.

 

Brian

[Art Kendall]

Below is an example of syntax for generating 10,000 throws of a pair of dice. (each die is considered a random number from 1 to 6).
There is a client at the door so I don't have time to see how it works in matrix mode, but this may give you a start.


*THROW 2 DICE.
SET SEED=20090515.
NEW FILE.
INPUT PROGRAM  .
LOOP id=1 to 10000.
COMPUTE die1=RND(RV.UNIFORM(.5,6.5)).
COMPUTE die2=RND(RV.UNIFORM(.5,6.5)).
END CASE.
END LOOP.
END FILE.
END INPUT PROGRAM.
FORMATS DIE1 DIE2 (F1).
CROSSTAB TABLES= DIE1 BY DIE2 /CELLS=ALL.

Art Kendall
Social Research Consultants

On 3/6/2010 8:51 AM, Dates, Brian wrote:

Is it possible to generate uniform random numbers in a specific range in matrix mode?  For example, if I want to create a vector (i=100, j=1) of random numbers between 3 and 10, there doesn't seem to be a solution.  If n=100 and I use compute x=trunc(uniform(100,1)*n), I get numbers between 1 and 10.  If I use x=trunc(uniform(100,1)*n+2), I get numbers between 3 and 12.  So in one case I get the desired top of the range, and in the other I get the desired bottom of the range.  Any assistance is appreciated.  Thanks.

 

Brian

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[Marta Garcia-Granero]

Hi Brian:

On 3/6/2010 8:51 AM, Dates, Brian wrote:
> Is it possible to generate uniform random numbers in a specific range
> in matrix mode?  For example, if I want to create a vector (i=100,
> j=1) of random numbers between 3 and 10, there doesn't seem to be a
> solution.  If n=100 and I use compute x=trunc(uniform(100,1)*n), I get
> numbers between 1 and 10.  If I use x=trunc(uniform(100,1)*n+2), I get
> numbers between 3 and 12.  So in one case I get the desired top of the
> range, and in the other I get the desired bottom of the range.
This gives the expected Min and Max values for X vector:

MATRIX.
COMPUTE X=3+TRUNC(8*UNIFORM(100,1)).
COMPUTE MinX=MMIN(X).
COMPUTE MaxX=MMAX(X).
PRINT {MinX,MaxX}
 /FORMAT='F8'
 /TITLE='Min & Max values'.
END MATRIX.

HTH,
Marta GG


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