# NTRAND

Returns uniform pseudo random number(s) in (0, 1) based on Mersenne Twister Algorithm which has long period (219937-1), high order of equidistribution and 623 dimensions.

### Syntax

NTRAND(

• Size,
• Algorithm,
• Random seed1,
• Random seed2

)

#### Parameters

• Size is # of random numbers (Positive integer).
• Algorithm is an integer value that determines a method to generate uniform random number.
• 0: Mersenne Twister(2002)
• 1: Mersenne Twister(1998)
• 2: Numerical Recipes ran2()
• Random seed1 is 1st. random seed.
• Random seed2 is 2nd. random seed.

### Remarks

• More precisely, a range of random number is
$[10^{-12},\;1-10^{-12}]$
• To generate uniform random numbers between a and b (a < b), use:
=(b-a)*NTRAND(100)+a
• To generate discrete random numbers in [m, n] (m and n are integer and m < n), use:
=INT(NTRAND(100)*(n-m+1))+m

For example, to model a dice (output is in [1,6]):

=INT(NTRAND(100)*6)+1

### Example

• The example may be easier to understand if you copy it to a blank worksheet
How to copy an example
1. Create a blank workbook or worksheet.
2. Select the example in the Help topic.

Note  Do not select the row or column headers.

Selecting an example from Help

3. Press CTRL+C.
4. In the worksheet, select cell A1, and press CTRL+V.
5. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

1
2

A B
Data Description
=NTRAND(100,0,12345,67890) 100 uniform random numbers by Mersenne Twister algorithm with random seeds 12345 and 67890

Note : The formula in the example must be entered as an array formula. After copying the example to a blank worksheet, select the range A2:A101 starting with the formula cell. Press F2, and then press CTRL+SHIFT+ENTER.